Difference between revisions of "ASCEND/C2/Writing-basic-model/English"

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| style="border:0.75pt solid #000001;padding:0.0104in;"| Let us begin the tutorial with a simple example.  
 
| style="border:0.75pt solid #000001;padding:0.0104in;"| Let us begin the tutorial with a simple example.  
  
In this example, let us solve 3 simultaneous equations with 3 unknowns
+
In this example, let us solve 3 simultaneous equations with 3 unknowns.
  
 
We will use a text editor like '''gedit''' to write our '''model'''
 
We will use a text editor like '''gedit''' to write our '''model'''
  
I already have the '''code''' for the example in a text file
+
|-
 +
| style="border:0.75pt solid #000001;padding:0.0104in;"|
 +
| style="border:0.75pt solid #000001;padding:0.0104in;"| I already have the '''code''' for the example in a text file
  
 
Let me explain the '''code'''
 
Let me explain the '''code'''
Line 70: Line 72:
 
| style="border:0.75pt solid #000001;padding:0.0104in;"| Highlight the “'''system.a4l'''” line
 
| style="border:0.75pt solid #000001;padding:0.0104in;"| Highlight the “'''system.a4l'''” line
 
| style="border:0.75pt solid #000001;padding:0.0104in;"| Initially we mention the '''library''' (that is a collection of pre-defined '''models''' that we need in our model).
 
| style="border:0.75pt solid #000001;padding:0.0104in;"| Initially we mention the '''library''' (that is a collection of pre-defined '''models''' that we need in our model).
 +
  
 
Here we require the basic '''system.a4l''' '''library'''
 
Here we require the basic '''system.a4l''' '''library'''
  
'''.a4l '''extension denotes the '''ascend4 library'''
+
|-
 
+
| style="border:0.75pt solid #000001;padding:0.0104in;"| Highlight the “'''system.a4l'''” line
the name of the '''library''' is written in double quotes
+
| style="border:0.75pt solid #000001;padding:0.0104in;"| '''.a4l '''extension denotes the '''ascend4 library'''
 
+
  
  
 +
The name of the '''library''' is written in '''double quotes'''.
  
 
|-
 
|-
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Highlight the semi colon
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Highlight the semi colon
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Note that semi colon is a statement terminator in '''ASCEND'''
+
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Note that '''semi colon''' is a '''statement terminator''' in '''ASCEND'''.
  
'''ASCEND''' considers all the statements as one sentence if semi colon is not put after each statement
+
'''ASCEND''' considers  
 +
*all the statements as one sentence  
 +
*if '''semi colon''' is not put after each '''statement'''.
  
 
|-
 
|-
Line 94: Line 99:
 
|-
 
|-
 
| style="border:0.75pt solid #000001;padding:0.0104in;"| Highlight (*variables declaration*)
 
| style="border:0.75pt solid #000001;padding:0.0104in;"| Highlight (*variables declaration*)
| style="border:0.75pt solid #000001;padding:0.0104in;"| In '''ASCEND''' '''comments''' are written in parenthesis enclosed with in a pair of asterik mark
+
| style="border:0.75pt solid #000001;padding:0.0104in;"| In '''ASCEND''' '''comments''' are written in '''parenthesis''' enclosed with in a pair of '''asterik mark'''.
  
'''Comments''' are not executed
 
  
They make the '''model '''easier to understand
+
'''Comments''' are not executed.
  
We will now define variables for our model
 
  
|-
+
They make the '''model '''easier to understand.
| style="border:0.75pt solid #000001;padding:0.0104in;"| Highlight '''solver_var'''
+
  
  
 +
We will now define the '''variables''' for our '''model'''.
 +
 +
|-
 +
| style="border:0.75pt solid #000001;padding:0.0104in;"| Highlight '''solver_var'''
  
| style="border:0.75pt solid #000001;padding:0.0104in;"| Any variable whose value is expected to be computed by '''ASCEND''' must be of type '''solver_var'''
+
| style="border:0.75pt solid #000001;padding:0.0104in;"| Any '''variable''' whose value is expected to be computed by '''ASCEND''', must be of type '''solver underscore var'''
  
 
|-
 
|-
Line 115: Line 121:
 
The definition of the type '''solver_var '''is predefined in the '''system.a4l library'''
 
The definition of the type '''solver_var '''is predefined in the '''system.a4l library'''
  
'''IS_A''' is an operator in '''ASCEND''' which is used to define variable types
+
'''IS underscore A''' is an operator in '''ASCEND''' which is used to define '''variable types'''.
  
 
|-
 
|-
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Highlight all the equation sequentially
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Highlight all the equation sequentially
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Equations to be solved are
+
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| The equations to be solved are
  
 
'''x+y+z = a*d'''
 
'''x+y+z = a*d'''
Line 127: Line 133:
 
'''5*x+2*y-3*z = 0'''
 
'''5*x+2*y-3*z = 0'''
  
Note that we have not mentioned how to solve this given set of equations.
+
|-
 
+
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Highlight continues
We have also not mentioned which variables are to be specified and which are to be calculated
+
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Note that we have not mentioned how to solve this given set of equations.
 
+
 
+
  
 +
We have also not mentioned which '''variables''' are to be specified and which are to be calculated.
  
 
|-
 
|-
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Highlight '''END my_model'''
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Highlight '''END my_model'''
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Now end this '''model '''with '''END my_model'''
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Now end this '''model '''with '''END my_model'''
 
 
 
  
 
|-
 
|-
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Show the loaded model on '''ASCEND''' interface
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Show the loaded model on '''ASCEND''' interface
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Now open this '''model''' in '''ASCEND'''
+
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Now open this '''model''' in '''ASCEND'''.
  
 
|-
 
|-
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Highlight the successful execution line in the message panel
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Highlight the successful execution line in the message panel
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Note that '''ASCEND''' has executed the '''on_load method''' by default
+
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Note that '''ASCEND''' has executed the '''on_load method''' by default.
 +
 
  
This can be seen from the message in the panel below
+
This can be seen from the message in the panel below.
  
 
|-
 
|-
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Highlight the values of the variables on '''ASCEND''' interface
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Highlight the values of the variables on '''ASCEND''' interface
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Observe that '''ASCEND''' has given the default value of 0.5 to each of the variable
+
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Observe that '''ASCEND''' has given default values of''' 0.5''' to each of the '''variables'''.
  
 
|-
 
|-
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Click the '''solve''' button
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Click the '''solve''' button
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Now click on the '''solve''' icon
+
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Now click on the '''Solve''' icon.
  
'''ASCEND '''displays the results
+
'''ASCEND '''displays the result.
  
 
|-
 
|-
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Highlight the converged message in the panel below
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Highlight the converged message in the panel below
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| This can be confirmed in the panel below
+
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| This can be confirmed in the panel below.
  
A converged message is displayed after the successful completion of the calculation
+
 
 +
A converged message is displayed after the successful completion of the calculations.
  
 
|-
 
|-
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Highlight the values of the variables '''y and d'''
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Highlight the values of the variables '''y and d'''
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Note that '''ASCEND''' squared the system automatically
+
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Note that '''ASCEND'''  
 
+
* squared the system automatically
Keping the values of two variables '''y and d''' as default value and calculated the value for rest of the variables
+
* by keping the values of two '''variables y''' and '''d''' as default values
 +
* and calculated the values for rest of the '''variables'''.
  
 
|-
 
|-
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Right click on '''d''' and assign it a value 1
+
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Right click on '''d''' and assign it a value 1.
  
Fix '''d '''by selecting the fixed option
+
Fix '''d '''by selecting the fixed option.
  
Repeat the same for '''x'''
+
Repeat the same for '''x'''.
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Now suppose we want to make '''x '''and '''d '''as our fixed variable by assigning values to them and solve for '''a, y '''and''' z'''
+
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Now suppose we want to  
 +
*make '''x '''and '''d '''as our fixed '''variables''''''Bold text''' by assigning values to them and solve for '''a, y '''and''' z'''.
  
Then, right click on '''d''' and select '''properties''' from the drop down menu
+
Then, right-click on '''d''' and select '''Properties''' from the drop down menu.
  
Under '''values''', assign a value to '''d'''
+
Under '''Values''', assign a value to '''d'''
  
Here I am giving the value 1
+
Here I am giving the value 1.
  
Now in solving section, select fixed
+
Now in '''Solving''' section, select '''Fixed'''.
  
Click on '''Apply''' and '''OK'''
+
Click on '''Apply''' and '''OK'''.
  
 
Now similarly repeat the same procedure for fixing the value of '''x'''
 
Now similarly repeat the same procedure for fixing the value of '''x'''
Line 195: Line 201:
 
|-
 
|-
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Highlight the corresponding results
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Highlight the corresponding results
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Observe that '''ASCEND''' has solve the '''model '''and you will have a new set of results
+
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Observe that '''ASCEND''' has solved the '''model '''and you will have a new set of results.
  
Note that the '''fixed''' variables are shown in green color and '''free''' variables, calculated by '''ASCEND''' are shown in blue color
 
  
Also note that the final result has been displayed with a tick mark and the '''fixed''' variables have been denoted by a closed lock icon
+
Note that the '''fixed variables''' are shown in green color and '''free variables''', calculated by '''ASCEND''' are shown in blue color.
  
We can also specify the '''fixed''' and '''free''' variables in the '''code''' and assigning value to the variables
 
  
In '''ASCEND''' the solution procedure is separate from the problem statement
+
Also note that the final results has been displayed with a '''tick mark''' and the '''fixed variables''' have been denoted by a '''closed lock icon'''.
  
'''Methods '''contain procedures to solve the model
+
 
 +
We can also specify the '''fixed''' and '''free variables''' in the '''code''' and assign values to the '''variables'''.
 +
 
 +
 
 +
In '''ASCEND''' the solution procedure is separate from the problem statement.
 +
 
 +
 
 +
'''Methods '''contain procedures to solve the '''model'''.
  
 
|-
 
|-
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Open '''my_model''' in '''gedit'''
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Open '''my_model''' in '''gedit'''
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| We will now explain different methods to solve our model
+
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| We will now explain different methods to solve our '''model'''.
  
Open the file '''my_model.a4c''' in a text editor
 
  
We write the '''methods''' after equations
+
Open the file '''my_model.a4c''' in a text editor.
 +
 
 +
 
 +
We write the '''methods''' after '''equations'''.
  
 
|-
 
|-
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Delete '''END my_model''' and remove asterik from '''METHODS''' and end of the code
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Delete '''END my_model''' and remove asterik from '''METHODS''' and end of the code
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Now remove the line '''END my_model'''
+
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Now remove the line '''END my_model'''.
  
Delete the parenthesis and asterik mark in front of methods and at the end of the code
 
  
 +
Delete the '''parenthesis''' and '''asterik mark''' in front of '''METHODS''' and at the end of the '''code'''.
  
 +
|-
 +
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Highlight the corresponding lines in the code sequentially
 +
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Under '''METHOD specify''', we fixed '''variables a''' and '''d'''.
 +
 +
 +
We also assign values to the '''variables''' as '''a = 1''' and '''d = 3'''.
  
  
 
|-
 
|-
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Highlighte the corrsponding lines in the code sequentially
+
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"|  
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Under '''method specify''', we fixed variable '''a''' and '''d'''
+
  
We also assign values to the variables as '''a = 1 and d=3''',note that to assign the values to a particular variable, we use '''a :''' and '''<nowiki>=</nowiki>''' sign together
+
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Note that to assign the values to a particular '''variable''', we use a '''colon''' and '''<nowiki>=</nowiki>''' sign together.
  
I will refer''' :=''' to sign as '''is equal to '''from here on
 
  
Under method '''on_load''' we run the '''method specify'''
+
I will refer''' := (colon and equal to)''' sign as '''is equal to '''from here on.
 +
 
 +
 
 +
|-
 +
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Highlight the corresponding lines in the code sequentially
 +
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Under '''METHOD on_load''', we run the '''METHOD specify'''.
  
This is the method that describes '''ASCEND '''the action to be taken when a '''model''' is loaded
+
This is the '''method''' that describes '''ASCEND '''the action to be taken when a '''model''' is loaded.
  
 
|-
 
|-
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Click on the '''save''' button
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Click on the '''save''' button
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Now end the '''method on_load''' and '''my_model''' and save this file
+
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Now end the '''METHOD on_load''' and '''my_model''' and save this file.
  
 
|-
 
|-
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Show the ascend interface
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Show the ascend interface
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Now open this with '''ASCEND'''
+
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Now open this with '''ASCEND'''.
  
 
|-
 
|-
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Select the '''on_load method '''and run the code
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Select the '''on_load method '''and run the code
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Now under '''methods '''select '''on_load'''
+
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Now under '''Methods '''select '''on_load'''
  
Click on '''run'''
+
Click on '''Run'''.
  
 
|-
 
|-
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Click on the '''solve''' button and highlight the asnwers
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Click on the '''solve''' button and highlight the asnwers
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Click on '''solve''' icon
+
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| And then click on '''Solve''' icon.
  
Observe that '''ASCEND''' has fixed the variable '''a''' and''' d''' and calculated the values for '''x,y '''and '''z'''
+
 
 +
Observe that '''ASCEND''' has fixed the '''variables a''' and''' d''' and calculated the values for '''x, y '''and '''z'''.
  
 
|-
 
|-
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Open the code file again in '''gedit'''
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Open the code file again in '''gedit'''
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Now open the code for '''my_model.a4c''' again
+
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Now open the '''code''' for '''my_model.a4c''' again.
  
 
|-
 
|-
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Carry out the required editing in the code file
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Carry out the required editing in the code file
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Now remove the values assigned under specify
+
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Now remove the values assigned under '''specify'''.
  
Now we will add a new '''method''' called '''values'''
+
|-
 +
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Type as per narration
 +
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"|Now we will add a new '''METHOD''' called '''values'''.
  
Type method values and then type '''a = 1, d= 2 '''and '''end values'''
 
  
Now under '''on_load''' type '''run values''' after '''run specify'''
+
Type '''METHOD values''' and then type '''a = 1, d= 2 '''and '''END values'''
 +
 
 +
|-
 +
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Type as per narration
 +
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"|Now under '''on_load''' type '''RUN values''' after '''RUN specify'''.
  
 
|-
 
|-
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Open the file with ascend
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Open the file with ascend
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Now save the file and open it with '''ASCEND'''
+
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Now save the file and open it with '''ASCEND'''.
  
 
|-
 
|-
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Run the code using '''on_laod method''' and press '''solve'''
+
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Run the code using '''on_load method''' and press '''solve'''
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Again run the '''method on_load''' and click on '''solve'''
+
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Again run the '''Method on_load''' and click on '''Solve'''.
  
You will see '''ASCEND''' has fixed variable''' a '''and '''d''' and assigned the values as mentioned under '''values''' section in the code
+
 
 +
You will see  
 +
*'''ASCEND''' has fixed '''variables a '''and '''d'''  
 +
*and assigned the values  
 +
*as mentioned under '''Values''' section in the '''code'''.
  
 
|-
 
|-
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Open the required code file in '''gedit'''
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Open the required code file in '''gedit'''
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Now let’s look at an interesting feature of dimensional consistency in '''ASCEND '''with the help of another model
+
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Now let’s look at an interesting feature of '''dimensional consistency''' in '''ASCEND '''with the help of another '''model'''.
  
Here we will compute the mass of a cylinder
 
  
I already have the code for this model
+
Here we will compute the '''mass''' of a '''cylinder'''.
  
Let me explain the code
 
  
Open''' cylinder.a4c''' with a text editor
+
|-
 +
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Type as per narration
 +
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"|I already have the '''code''' for this '''model'''.
 +
 
 +
Let me explain the '''code'''.
 +
 
 +
Open''' cylinder.a4c''' with a text editor.
  
 
|-
 
|-
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Highlight the corresponding line in a sequential order
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Highlight the corresponding line in a sequential order
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Note that here we require '''atoms.a4l''' library as compared to '''systems library '''used earlier in the last '''model'''
+
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Note that, *here we require '''atoms.a4l''' library  
 +
*as compared to '''systems library, '''used earlier in the last '''model'''
  
'''atoms '''is a refined version of '''systems library'''
 
  
and contains the definition of various variable types that represent different physical units
+
|-
 +
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Highlight continues
 +
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"|
 +
*'''atoms '''is a refined version of '''systems library'''.
 +
*and contains the definition of various variable types  
 +
*that represent different physical units
  
For example we write v is a volume
 
  
m is a mass etc.
+
|-
 +
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Highlight the corresponding line in a sequential order
 +
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| For example, we write
 +
*'''v is a volume'''
 +
*'''m is a mass''' etc.
  
Volume, mass etc. are different variable types defined in '''atoms.a4l'''
+
'''Volume, mass''' etc. are different''' variable types''' defined in '''atoms.a4l'''
 +
 
 +
This helps in ensuring that the equations written in '''ASCEND models''' are '''dimensionally consistent'''.
 +
 
 +
|-
 +
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Scroll down the code
 +
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| After this we write '''equations''' and '''methods''' as explained earlier.
 +
 
 +
 
 +
|-
 +
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Highlight the corresponding line in a sequential order
 +
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Note that, while specifying values for these '''variable types''', we need to mention the corresponding physical units in '''curly brackets'''..
  
This helps in ensuring that the equations written in '''ASCEND model''' are dimensionally consistent
 
  
After this we write equations and '''methods''' as explained earlier
+
Here we write '''V = 100 cm cube '''and '''p = 100 kg per metre cube'''.
  
Note that while specifying values for these variable types, we need to mention the corresponding physical units in curly brackets
 
  
Here we write V = 100 '''cm^3 '''and p = 100'''kg/m^3'''
+
Note that '''v''' is in '''CGS units''' while '''p''' is in '''SI units'''.
  
Note that V is in CGS units while p is in SI units
 
  
The user doesn't have to worry about the units as '''ASCEND''' itself performs the unit conversion
+
The user doesn't have to worry about the '''units''' as '''ASCEND''' itself performs the '''unit conversion'''.
  
 
|-
 
|-
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Open the file in ASCEND and run and solve it using the on_load method
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Open the file in ASCEND and run and solve it using the on_load method
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Now open this file in '''ASCEND'''
+
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Now open this file in '''ASCEND'''.
  
Now once again run the '''on_load method'''
+
Now once again run the '''on_load Method''' and solve the problem.
 
+
and solve the problem
+
  
 
|-
 
|-
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Highlight the answers
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Highlight the answers
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Observe that '''ASCEND''' has converted the values of volume into SI units and then calculated the mass in SI units
+
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Observe that '''ASCEND''' has converted the values of '''volume''' into '''SI units''' and then calculated the '''mass''' in '''SI units'''
  
Note that '''ASCEND''' by default uses SI units until specified otherwise
+
 
 +
Note that '''ASCEND''', by default, uses '''SI units''' until specified otherwise.
  
 
|-
 
|-
Line 336: Line 387:
  
 
Summary
 
Summary
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Now let us summarize,in this tutorial,
+
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Now let us summarize.
  
We have learned how to
+
In this tutorial,
 +
 
 +
We have learnt how to
  
 
* Build a basic '''model'''
 
* Build a basic '''model'''
 
* Add '''methods''' to the basic '''model''' and
 
* Add '''methods''' to the basic '''model''' and
* Write dimensionally consistent equations
+
* Write '''dimensionally consistent equations'''
 
+
 
+
  
 
|-
 
|-
Line 352: Line 403:
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Do the following assignment
 
| style="border-top:none;border-bottom:0.75pt solid #000001;border-left:0.75pt solid #000001;border-right:0.75pt solid #000001;padding:0.0104in;"| Do the following assignment
  
Edit the '''model cylinder '''in a text editor and make it dimensionally inconsistent
+
#Edit the '''model cylinder '''in a text editor and make it '''dimensionally inconsistent'''
 
+
#For example, write '''m is a distance''' instead of '''mass'''
For example, write '''m is a distance''' instead of mass
+
#Now run this '''dimensionally inconsistent model''' in '''ASCEND '''and observe the output
 
+
#Add more '''variables''' and '''equations''' to the '''model cylinder.a4c''' and solve it in '''ASCEND'''
Now run this dimensionally inconsistent model in '''ASCEND '''and observe the output
+
 
+
Add more variables and equations to the '''model cylinder.a4c''' and solve it in ASCEND
+
  
 
|-
 
|-

Latest revision as of 20:39, 6 July 2014

Tutorial 3: Developing a Basic model in ASCEND


Visual Cue
Narration
Open Slide number 1

Title slide

Welcome to the spoken tutorial on Developing a Basic Model in ASCEND
Open Slide 2

Learning Objectives

In this tutorial,

We will learn how to

  • Build a basic model
  • Add methods to the basic model and
  • Write dimensionally consistent equations


Open Slide number 3

System Requirement

Here I am using
  • Ubuntu Linux OS v. 12.04
  • ASCEND v. 0.9.8


Open Slide number 4

Pre-requisites

To know more about ASCEND

Please visit ascend4.org

For relevant tutorials please visit our website

http://spoken-tutorial.org

Open Slide number 5

Example

Let us begin the tutorial with a simple example.

In this example, let us solve 3 simultaneous equations with 3 unknowns.

We will use a text editor like gedit to write our model

I already have the code for the example in a text file

Let me explain the code

Open mymodel.a4c in gedit Open the file mymodel.a4c in a text editor
Highlight the “system.a4l” line Initially we mention the library (that is a collection of pre-defined models that we need in our model).


Here we require the basic system.a4l library

Highlight the “system.a4l” line .a4l extension denotes the ascend4 library


The name of the library is written in double quotes.

Highlight the semi colon Note that semi colon is a statement terminator in ASCEND.

ASCEND considers

  • all the statements as one sentence
  • if semi colon is not put after each statement.
Highlight MODEL my_model MODEL my_model begins a model with name my_model

You can give any name to the model

Highlight (*variables declaration*) In ASCEND comments are written in parenthesis enclosed with in a pair of asterik mark.


Comments are not executed.


They make the model easier to understand.


We will now define the variables for our model.

Highlight solver_var Any variable whose value is expected to be computed by ASCEND, must be of type solver underscore var
Highlight all the defined variables Thus we define variable x,y,z,d and a as a solver_var

The definition of the type solver_var is predefined in the system.a4l library

IS underscore A is an operator in ASCEND which is used to define variable types.

Highlight all the equation sequentially The equations to be solved are

x+y+z = a*d

x+y+2*z = 5 and

5*x+2*y-3*z = 0

Highlight continues Note that we have not mentioned how to solve this given set of equations.

We have also not mentioned which variables are to be specified and which are to be calculated.

Highlight END my_model Now end this model with END my_model
Show the loaded model on ASCEND interface Now open this model in ASCEND.
Highlight the successful execution line in the message panel Note that ASCEND has executed the on_load method by default.


This can be seen from the message in the panel below.

Highlight the values of the variables on ASCEND interface Observe that ASCEND has given default values of 0.5 to each of the variables.
Click the solve button Now click on the Solve icon.

ASCEND displays the result.

Highlight the converged message in the panel below This can be confirmed in the panel below.


A converged message is displayed after the successful completion of the calculations.

Highlight the values of the variables y and d Note that ASCEND
  • squared the system automatically
  • by keping the values of two variables y and d as default values
  • and calculated the values for rest of the variables.
Right click on d and assign it a value 1.

Fix d by selecting the fixed option.

Repeat the same for x.

Now suppose we want to
  • make x and d as our fixed variables'Bold text by assigning values to them and solve for a, y and z'.

Then, right-click on d and select Properties from the drop down menu.

Under Values, assign a value to d

Here I am giving the value 1.

Now in Solving section, select Fixed.

Click on Apply and OK.

Now similarly repeat the same procedure for fixing the value of x

Highlight the corresponding results Observe that ASCEND has solved the model and you will have a new set of results.


Note that the fixed variables are shown in green color and free variables, calculated by ASCEND are shown in blue color.


Also note that the final results has been displayed with a tick mark and the fixed variables have been denoted by a closed lock icon.


We can also specify the fixed and free variables in the code and assign values to the variables.


In ASCEND the solution procedure is separate from the problem statement.


Methods contain procedures to solve the model.

Open my_model in gedit We will now explain different methods to solve our model.


Open the file my_model.a4c in a text editor.


We write the methods after equations.

Delete END my_model and remove asterik from METHODS and end of the code Now remove the line END my_model.


Delete the parenthesis and asterik mark in front of METHODS and at the end of the code.

Highlight the corresponding lines in the code sequentially Under METHOD specify, we fixed variables a and d.


We also assign values to the variables as a = 1 and d = 3.


Note that to assign the values to a particular variable, we use a colon and = sign together.


I will refer := (colon and equal to) sign as is equal to from here on.


Highlight the corresponding lines in the code sequentially Under METHOD on_load, we run the METHOD specify.

This is the method that describes ASCEND the action to be taken when a model is loaded.

Click on the save button Now end the METHOD on_load and my_model and save this file.
Show the ascend interface Now open this with ASCEND.
Select the on_load method and run the code Now under Methods select on_load

Click on Run.

Click on the solve button and highlight the asnwers And then click on Solve icon.


Observe that ASCEND has fixed the variables a and d and calculated the values for x, y and z.

Open the code file again in gedit Now open the code for my_model.a4c again.
Carry out the required editing in the code file Now remove the values assigned under specify.
Type as per narration Now we will add a new METHOD called values.


Type METHOD values and then type a = 1, d= 2 and END values

Type as per narration Now under on_load type RUN values after RUN specify.
Open the file with ascend Now save the file and open it with ASCEND.
Run the code using on_load method and press solve Again run the Method on_load and click on Solve.


You will see

  • ASCEND has fixed variables a and d
  • and assigned the values
  • as mentioned under Values section in the code.
Open the required code file in gedit Now let’s look at an interesting feature of dimensional consistency in ASCEND with the help of another model.


Here we will compute the mass of a cylinder.


Type as per narration I already have the code for this model.

Let me explain the code.

Open cylinder.a4c with a text editor.

Highlight the corresponding line in a sequential order Note that, *here we require atoms.a4l library
  • as compared to systems library, used earlier in the last model


Highlight continues
  • atoms is a refined version of systems library.
  • and contains the definition of various variable types
  • that represent different physical units


Highlight the corresponding line in a sequential order For example, we write
  • v is a volume
  • m is a mass etc.

Volume, mass etc. are different variable types defined in atoms.a4l

This helps in ensuring that the equations written in ASCEND models are dimensionally consistent.

Scroll down the code After this we write equations and methods as explained earlier.


Highlight the corresponding line in a sequential order Note that, while specifying values for these variable types, we need to mention the corresponding physical units in curly brackets..


Here we write V = 100 cm cube and p = 100 kg per metre cube.


Note that v is in CGS units while p is in SI units.


The user doesn't have to worry about the units as ASCEND itself performs the unit conversion.

Open the file in ASCEND and run and solve it using the on_load method Now open this file in ASCEND.

Now once again run the on_load Method and solve the problem.

Highlight the answers Observe that ASCEND has converted the values of volume into SI units and then calculated the mass in SI units


Note that ASCEND, by default, uses SI units until specified otherwise.

Open Slide number 5:

Summary

Now let us summarize.

In this tutorial,

We have learnt how to

  • Build a basic model
  • Add methods to the basic model and
  • Write dimensionally consistent equations
Open Slide number 6:

Assignment

Do the following assignment
  1. Edit the model cylinder in a text editor and make it dimensionally inconsistent
  2. For example, write m is a distance instead of mass
  3. Now run this dimensionally inconsistent model in ASCEND and observe the output
  4. Add more variables and equations to the model cylinder.a4c and solve it in ASCEND
Open Slide number 7

About the Spoken Tutorial Project

Information on the spoken tutorial project is available on our website

spoken-tutorial.org

Open Slide number 8

Spoken Tutorial Workshops

Details on Workshops based on spoken tutorials is also available on the website
Open Slide number 9

Acknowledgements

Spoken tutorial project is funded by NMEICT,MHRD



Open Slide number 10

Thank You

This is Priya Bagde from IIT Bombay signing off

Thank You for joining

Contributors and Content Editors

Nancyvarkey, Tarung