Kaushik Datta at 07:01, 22 March 2016

2016-03-22T07:01:27Z

Nancyvarkey at 02:16, 22 March 2016

2016-03-22T02:16:53Z

Nancyvarkey at 02:12, 22 March 2016

2016-03-22T02:12:48Z

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Kaushik Datta at 12:16, 21 March 2016

2016-03-21T12:16:26Z

Kaushik Datta at 12:15, 21 March 2016

2016-03-21T12:15:21Z

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Kaushik Datta: Created page with "{| border=1 ||'''Visual Cue''' ||'''Narration''' |- || Slide: '''Title Slide''' || Welcome to the Spoken Tutorial on '''Array Functions and Operations'''. |- || Slide: '''..."

2016-03-19T07:52:17Z

Created page with "{| border=1 ||'''Visual Cue''' ||'''Narration''' |- || Slide: '''Title Slide''' || Welcome to the Spoken Tutorial on '''Array Functions and Operations'''. |- || Slide: '''..."

New page

{| border=1
||'''Visual Cue'''
||'''Narration'''

|-
|| Slide:

'''Title Slide'''
|| Welcome to the Spoken Tutorial on '''Array Functions and Operations'''.

|-
|| Slide:

'''Learning Objectives'''
|| In this tutorial, we are going to learn:

* how to use '''OMShell'''

* how to use '''array construction functions'''.
* how to perform '''arithmetic operations''' on '''vectors''' and '''matrices'''.
* how to use '''conversion functions'''.

|-
|| Slide:

'''System Requirements'''
|| To record this tutorial, I am using

* '''OpenModelica 1.9.2'''
* '''Ubuntu Operating System version 14.04''' and
* '''gedit'''

'''Windows''' users may use any text editor like '''Notepad''' instead of '''gedit'''.

|-
|| Slide:

'''Prerequisites'''
|| To understand and practice this tutorial, you need

* knowledge of '''function''' and '''array declaration''' in '''Modelica'''.
* Prerequisite tutorials are mentioned on our website.

|-
|| Slide:

'''OMShell'''
|| '''OMShell''' is an interactive command line tool. It is a part of '''OpenModelica'''.

'''OpenModelica compiler''' can be invoked using '''commands''' typed in '''OMShell'''.

It can be used for loading '''classes''' and simulating them.

'''Functions''' can also be called in '''OMShell'''.

|-
||
|| We shall now use '''classes''' named '''polynomialEvaluatorUsingVectors''' and '''functionTester''' to demonstrate OMShell.

These '''classes''' were discussed in the previous tutorials.

For more information on these '''classes''', please watch the prerequisite tutorials.

All the '''commands''' to be used in this tutorial are provided in a file named '''OMShell-commands.txt'''.

You may locate and download all the '''code files''' available on our website.

Please save all these code files in one directory for easy access.

|-
|| Click on '''Search''' icon in '''Icon Tray'''.
|| Let me launch '''OMShell'''.

To open '''OMShell''' on '''Ubuntu''' Operating System,

Click on '''Dash Home''' icon at top left in the launcher.

|-
|| Type '''OMShell''' in the address box.
|| Type '''OMShell''' in the address box.

Click on '''OMShell''' icon.

In '''Windows''', you may find it in '''Start''' menu.

|-
|| /* OMShell */
|| '''OMShell''' has now opened.

Let me resize the window for better visibility.

Let us learn a few useful '''commands'''.

|-
||
|| Now, go to the location where you saved the text file named '''OMShell-commands.txt''' and open it.

Note that this file has all the '''commands''' to be used in this tutorial.

Hence, you may refer to this file whenever in doubt.

Let me switch to '''OMshell'''.

|-
|| Type // '''cd()''' //
|| Type '''cd open and close parentheses'''.

Press '''Enter''' to display the result produced on execution of the '''command'''.

|-
||
|| This prints the path to current directory.

|-
|| Type // '''cd(“path”)''' //
|| Change current directory to the location where you have saved the '''code files'''.

Let me change directory on my system.

Type '''cd(open and close parentheses) (within double quotes)''' .

Specify the path and press '''Enter'''.

|-
||
|| Note that a '''Windows''' path uses '''forward slash''' unlike the '''backward slash''' in '''Ubuntu'''.

'''Windows''' users need to be cautious of this fact.

|-
|| Type // '''loadFile(“polynomialEvaluatorUsingVectors.mo”) '''//
|| Let us load '''polynomialEvaluatorUsingVectors''' function.

Type '''loadFile (within parentheses) (within double quotes)'''.

Type '''polynomialEvaluatorUsingVectors.mo'''.

Note that '''F''' is upper-case in '''loadFile()''' command.

'''loadFile''' command can be used to load '''class''' or '''model''' files with a file extension of '''.mo''' and press '''Enter'''.

|-
|| // '''true''' //
|| If the file is found, '''OMShell''' returns '''true'''.

|-
|| Type // '''polynomialEvaluatorUsingVectors(10) //'''
|| Let us call this function interactively.

Type '''polynomialEvaluatorUsingVectors (with an argument of) 10'''.

Press '''Enter'''.

|-
||
|| This command takes an input argument of '''10''' units and displays the result.

|-
|| Type // '''loadFile(“functionTester.mo”) '''//
|| Let me load '''functionTester''' class.

Type '''loadFile(functionTester.mo)'''

|-
|| Type // '''simulate(functionTester,startTime=0,stopTime=1) '''//
|| Let us simulate '''functionTester'''.

Type '''simulate (within brackets) functionTester (comma) startTime (equals) 0 (comma) stopTime (equals) 1''' and press '''Enter'''.

|-
||
|| The simulation is complete.

Let us plot variable '''z''' from '''functionTester class.

|-
|| Type // '''plot({z}) '''//
|| Type '''plot (within parentheses) (within curly braces) z''' and press '''Enter'''.

This generates a plot of variable '''z''' vs '''time'''.

|-
||
|| Let me go back to the slides.

|-
|| Slide:

'''Array Construction Functions'''

* fill()
* zeros()
* identity()

|| '''Array construction functions''' are used to construct '''arrays''' of given size.

Now let us take a look at a few '''array construction functions'''.

We will also practice them using '''OMShell'''.

'''fill()''' is used to construct '''arrays''' with all the elements same.

The syntax for '''fill''' is as shown.

First '''argument''' represents the number which fills the '''array'''.

Remaining '''arguments''' represent the size of each dimension of the array.

'''zeros()''' function is used to create an '''array''' filled with zeros.

Syntax for '''zeros()''' function is as shown.

'''Arguments''' represent the size of each dimension.

'''identity()''' function creates an identity matrix.

It takes one '''argument''' that represents the size of both dimensions.

|-
||
|| Let me demonstrate these functions using '''OMShell'''.

Let me go back to '''OMShell'''.

|-
|| /* OMShell */

Type // '''fill(5,2,2)''' //
|| Type '''fill(within parentheses) 5 (comma) 2 (comma) 2'''.

This command generates a two by two matrix with all its elements '''5'''.

The first arguments represents element to be filled.

The second argument represents first dimension of the array.

whereas the third argument, that is, '''2''', represents second dimension of the array.

|-
||
|| Hence, using the function '''fill''', one may generate arrays of any dimension with a given number.

|-
|| Type // '''zeros(2,2)''' //
|| Let us use '''zeros()''' function to create a (two by two) matrix with all its elements zero.

Type '''zeros (within parentheses) 2 (comma) ''' and press '''Enter'''.

The result is as expected.

|-
|| Type // '''identity(3)''' //
|| Let us now try '''identity''' function.

Type '''identity(3)''' and press '''Enter'''.

Note that it creates a 3 (by) 3 identity matrix.

|-
||
|| We can also perform '''arithmetic operations''' and use '''assignment statements''' in '''OMShell'''.

|-
|| Type // '''a:=[1,2;3,4] '''//
|| Let us create two matrices and perform '''arithmetic operations''' on them.

Type '''a (colon) (equals) (within square brackets) 1 (comma) 2 (semicolon) 3 (comma) 4''' and press '''Enter.

'''Comma''' is used to separate elements in a row whereas '''semi-colon''' is uses to separate rows themselves.

|-
|| Type // '''b:=identity(2) '''//
|| Type '''b (colon) (equals) identity (within brackets) 2''' and press '''Enter'''.

|-
|| Type // '''a + b '''//
|| Type '''a (plus) b''' and press '''Enter'''.

This performs matrix addition.

|-
|| Type // '''a * b''' //
|| Type '''a (asterisk) b''' and press '''Enter'''.

This performs matrix multiplication.

|-
|| Type // '''a .* b''' //
|| Type '''a (dot) (asterisk) b'''.

Press '''Enter'''.

This performs element-wise multiplication of the two matrices.

|-
||
|| Note that it is not necessary to define data-types of variables used in '''OMShell'''.

|-
||
|| Let me switch back to the slides.

|-
|| Slide:

'''Reduction Functions'''
|| '''Reduction functions''' take an '''array''' as '''input''' and return '''scalar''' as '''output'''.

'''min()''' function returns the minimum value in an array.

'''max()''' function returns the maximum value in an array.

'''sum()''' function returns the sum of all elements in an array.

'''product()''' function returns the product of all elements in an array.

|-
||
|| Let me switch to '''OMShell''' to demonstrate these functions.

|-
|| '''x = [3,4;5,6]'''
|| Let me create a new matrix '''x'''.

Type '''x (colon)(equals) 3 (comma) 4 (semicolon) 5 (comma) 6'''.

|-
|| Type // '''min(x)''' //
|| Let us apply each one of those functions on '''x'''.

Type '''min (within brackets) x''' and press '''Enter'''.

It returns the minimum value in '''x'''.

|-
|| Type // '''max(x)''' //
|| Type '''max (within brackets) x''' and press '''Enter'''.

It returns the maximum value in '''x'''.

|-
|| Type // '''sum(x) '''//
|| Type '''sum (within brackets) x'''.

Press '''Enter'''.

It returns the sum of all elements in '''x'''.

|-
|| Type // '''product(x)''' //
|| Type '''product (within brackets) x'''.

Press '''Enter'''

It returns the product of all elements in '''x'''.

|-
||
|| Let me go back to the slides.

|-
|| Slide:

'''Miscellaneous functions'''
|| Let us now discuss various other functions that take an '''array''' as '''input'''.

'''abs()''' is a function that returns an array with the absolute values of all its elements.

'''size()''' returns a vector with the size of each dimension.

'''ndims()''' function returns the number of dimensions in an array.

|-
||
|| This brings us to the end of this tutorial.

In this tutorial, we used '''OMShell''' to interactively demonstrate '''array functions'''.

These functions are part of '''Modelica''' language specification.

Hence, they may be used while writing '''classes''' in '''OMEdit''' as well.

|-
|| Slide:

'''Assignment'''
|| As an assignment, apply '''abs(), size()''' and '''ndims()''' to an array..

Secondly, we have used a two-dimensional array or matrix as an argument to most of the functions.

As an assignment, implement all these functions with higher dimensional arrays.

|-
||
|| This brings us to the end of this tutorial.

|-
|| Slide:

About the '''Spoken Tutorial project'''
|| Watch the video available at the link shown below.

[http://spoken-tutorial.org/ http][http://spoken-tutorial.org/ ://][http://spoken-tutorial.org/ spoken][http://spoken-tutorial.org/ -][http://spoken-tutorial.org/ tutorial][http://spoken-tutorial.org/ .][http://spoken-tutorial.org/ org] /What\_is\_a\_Spoken\_Tutorial

|-
|| Slide:

'''Spoken Tutorial''' Workshops
|| We conducts workshops using spoken tutorials.

Give certificates.

Please contact us.

|-
|| Slide:

'''Forum to answer questions'''
|| If you have questions in this tutorial, please visit the webpage mentioned.

|-
|| Slide:

'''Textbook Companion Project'''
|| We coordinate coding of solved examples from popular books.

We give honorarium to contributors.

Please visit our website.

|-
|| Slide:

'''Lab Migration Project'''
|| We help migrate labs from commercial simulators to '''OpenModelica'''.

|-
|| Slide:

'''Acknowledgements'''
|| '''Spoken Tutorial Project''' is supported by '''NMEICT, MHRD''' Government of India.

|-
|| Slide:

'''Thanks'''
|| We thank '''OpenModelica''' development team for their support.

|-
||
|| Thank you for joining me in this tutorial.

Goodbye!

@@ Line 85: / Line 85: @@
 |-
 || Type '''OMShell''' >> click on '''OMShell''' icon
-|| Type '''OMShell''' in the search box.
+|| Type '''OMShell''' in the search bar.

@@ Line 145: / Line 145: @@
 |-
-||
+||Highlight
-||Highlight
+||Note that '''F''' is upper-case in '''loadFile()''' command.
 Note that '''F''' is upper-case in '''loadFile()''' command.
 |-
@@ Line 196: / Line 195: @@
 |-
-|| Type // '''plot({z}) '''//
+|| Type // '''plot({z}) '''// >> press '''Enter'''
 || Type '''plot''' (within parentheses) (within curly braces) '''z''' and press '''Enter'''.
@@ Line 202: / Line 201: @@
 |-
-||
+|| Back to the slides
 || Now let me go back to the slides.
@@ Line 306: / Line 305: @@
 |-
-|| Type // '''b:=identity(2) '''//
+|| Type // '''b:=identity(2) '''// >> press '''Enter'''
 || Type '''b''' (colon) (equals) '''identity (2)'''.
@@ Line 338: / Line 337: @@
 |-
-||
+||Back to the slides
 || Now let me switch back to the slides.
@@ Line 398: / Line 397: @@
 |-
-||
+|| '''Summary Slide'''
 || This brings us to the end of this tutorial.