Sandhya.np14 at 09:03, 20 August 2018

2018-08-20T09:03:02Z

Sandhya.np14 at 09:01, 20 August 2018

2018-08-20T09:01:48Z

Jyotisolanki: Created page with "{| border=1 ||''' Time ''' ||'''Narration''' |- || 00:01 || Welcome to the spoken tutorial on '''Arrays'''. |- || 00:05 || In this tutorial, we are going to learn: How to d..."

2017-10-03T11:08:24Z

Created page with "{| border=1 ||''' Time ''' ||'''Narration''' |- || 00:01 || Welcome to the spoken tutorial on '''Arrays'''. |- || 00:05 || In this tutorial, we are going to learn: How to d..."

New page

{| border=1
||''' Time '''
||'''Narration'''

|-
|| 00:01
|| Welcome to the spoken tutorial on '''Arrays'''.

|-
|| 00:05
|| In this tutorial, we are going to learn: How to declare '''array''' variables, How to construct '''arrays''', How to use '''for''' and '''while''' loops and How to use '''OMShell'''.

|-
|| 00:20
|| To record this tutorial, I am using: '''OpenModelica 1.9.2'''

|-
|| 00:26
||You may use any of the following operating systems to practice this tutorial.

|-
||00:32
|| To understand and practice this tutorial:You need knowledge of '''arrays''' in any programming language.

|-
|| 00:40
||You need to know how to define a '''class''' in '''Modelica'''. Prerequisite tutorials are mentioned on our website. Please go through them.

|-
|| 00:50
|| '''Vector''' is a one dimensional array.

|-
|| 00:53
||It has single index.

|-
|| 00:55
||'''Syntax''' for vector declaration is as shown.

|-
|| 00:50
||The example shown declares a vector variable '''a''' whose size is '''2'''.

|-
|| 01:05
||A '''vector''' can be constructed by including the elements in curly braces.

|-
|| 01:11
||This example defines a '''vector''' parameter '''a''' with '''2''' and '''3''' as its elements.

|-
|| 01:19
|| To access the elements of a '''vector''', it is necessary to understand '''indexing'''.

|-
|| 01:25
||'''Syntax''' for '''vector indexing''' is as shown.

|-
|| 01:29
||'''Vector indexing''' starts from '''1''' and '''Indices''' must be '''integers'''.

|-
|| 01:35
|| Let us develop a '''function''' named '''polynomialEvaluatorUsingVectors'''.

|-
|| 01:41
||This '''function''' is an extension of '''polynomialEvaluator''' function which was discussed in previous tutorials.

|-
|| 01:49
||We shall replace parameters '''a,b''' and '''c''' of '''polynomialEvaluator''' with a vector '''a'''.

|-
|| 01:58
|| Please download and save all the files available on our '''Code Files''' link.

|-
|| 02:05
||For your convenience, '''polynomialEvaluator''' function is also made available.

|-
||02:12
|| Now let me switch to '''OMEdit''' to demonstrate this function.

|-
|| 02:17
||'''OMEdit''' is now open in '''Welcome''' perspective.

|-
|| 02:21
||I have opened all the necessary files.

|-
|| 02:25
||Note that the following classes or functions are now open in OMEdit: '''functionTester''',
'''matrixAdder''', '''polynomialEvaluator''' and '''polynomialEvaluatorUsingVectors'''.

|-
||02:42
|| Now, to view them let me double click on each icon.

|-
|| 02:49
||Let me shift the '''OMEdit''' window to the left for better visibility.

|-
|| 02:56
||Go to '''polynomialEvaluator''' tab.

|-
|| 03:00
||Open it in '''Text View'''.

|-
|| 03:03
||For more information on this '''function''', refer to the previous tutorials.

|-
|| 03:09
|| Let me go to '''polynomialEvaluatorUsingVectors'''. Open it in '''Text View'''.

|-
|| 03:16
|| '''Input''' and '''output''' variables are the same as in '''polynomialEvaluator''' function.

|-
|| 03:23
|| Parameters '''a,b''' and '''c''' of '''polynomialEvaluator''' are replaced with a vector '''a'''.

|-
||03:32
|| Size of this vector is '''3'''.

|-
||03:36
|| The elements of this vector are included in curly braces as shown.

|-
|| 03:42
||The elements are separated by a '''comma'''.

|-
|| 03:46
|| In the '''assignment''' statement the elements of vector '''a''' are accessed using their indices.

|-
|| 03:54
||'''a[1]''' is the first element of vector '''a'''.

|-
|| 03:59
|| Similarly, the second element and third element of vector '''a''' have been accessed as well.

|-
|| 04:08
|| Now, let me switch to '''functionTester''' tab.

|-
|| 04:13
||Open it in '''Text View'''.

|-
|| 04:16
||This class is similar to the '''functionTester''' class discussed in previous tutorial.

|-
|| 04:24
|| '''z''' is a Real variable.

|-
|| 04:27
|| '''polynomialEvaluatorUsingVectors''' function is called with an '''input''' argument of '''10''' units.

|-
|| 04:35
|| The value returned by this function is equated to '''z'''.

|-
|| 04:40
||Now let me Simulate this class.

|-
|| 04:43
|| Click on '''Simulate''' button.

|-
|| 04:46
||Close the pop up window.

|-
|04:49
|| Select '''z''' in the '''variables''' browser.

|-
|| 04:53
||Note that the value of '''z''' is equal to '''f(x)''' at '''x = 10'''.

|-
|| 05:00
||This plot is the same as observed in the case of '''polynomialEvaluator''' function.

|-
|| 05:07
||Now let me de-select '''z''' and delete the result.

|-
|| 05:13
|| Go back to '''Modeling perspective'''

|-
|| 05:16
|| Now let me switch to the slides.

|-
|| 05:19
|| '''for''' loop is used to iterate statements a given number of times.

|-
|| 05:24
||It can be used in '''algorithm''' and '''equation''' sections.

|-
|| 05:29
||'''Syntax''' for '''for''' loop is as shown with an example.

|-
|| 05:34
|| To demonstrate how to use '''for''' loop let me go back to '''OMEdit'''.

|-
|| 05:40
|| Click on '''polynomialEvaluatorUsingVectors''' tab.

|-
|| 05:45
|| In the '''assignment''' statement for '''fx''', we are accessing the elements of vector '''a'''.

|-
|| 05:52
||This can also be done using a '''for''' loop.

|-
|| 05:55
||Now, let us see how to include a '''for''' loop in the '''algorithm''' section.

|-
|| 06:01
|| Firstly, '''Comment''' the assignment statement for '''fx''' by inserting double slash at the beginning and end.

|-
|| 06:10
||Save this function by pressing '''Ctrl+S'''.

|-
|| 06:15
|| The '''for''' loop to be inserted has been provided in a text file named '''for-loop.txt'''.

|-
|| 06:23
||It is available on our website. I have opened this file using '''gedit'''.

|-
|| 06:29
||Windows users may use '''notepad''' or any other text editor to open it.

|-
|| 06:35
|| Let me go to '''gedit'''.

|-
|| 06:38
|| Copy all the statements by pressing '''Ctrl+C'''.

|-
|| 06:44
||Go back to '''OMEdit'''

|-
|| 06:46
|| Press '''Enter'''. Paste all the statements by pressing '''Ctrl + V'''.

|-
|| 06:53
||Save this function by pressing '''Ctrl + S'''.

|-
|| 06:57
|| Now, let me explain each statement of this loop.

|-
|| 07:02
||This statement assigns '''fx '''an initial value of zero before the loop starts.

|-
|| 07:09
|| Here, '''i''' serves as a loop counter.

|-
|| 07:12
||The loop runs until value of '''i''' is '''3'''.

|-
|| 07:16
||It is not necessary to declare '''i''' before it is used.

|-
|| 07:21
||Let me scroll down a bit.

|-
|| 07:24
|| This statement iteratively adds terms of the polynomial '''f(x)'''.

|-
|| 07:30
||Polynomial '''f(x)''' has been discussed while discussing '''polynomialEvaluator''' function.

|-
|| 07:37
|| This statement indicates the end of '''for''' loop.

|-
|| 07:41
|| Now, this function is complete.

|-
|| 07:44
||To test this function let us use the class '''functionTester'''.

|-
|| 07:49
||I have made no changes to this function to this '''class'''.

|-
|| 07:54
|| let me simulate this class by pressing '''Simulate''' button in the toolbar.

|-
|| 07:49
|| Select '''z''' in '''variables browser'''.

|-
|| 08:03
||Note that the value of '''z''' remains the same after changes are made to the function.

|-
|| 08:10
||Let me de-select '''z''' and delete the result.

|-
|| 08:14
|| Go back to '''Modeling perspective'''

|-
|| 08:17
|| Now let me go back to the slides once again.

|-
|| 08:21
|| '''while''' loop is used to iterate statements until a given condition is satisfied.

|-
|| 08:27
||'''while''' loop cannot be used in '''equation''' section.

|-
|| 08:31
||'''for ''' loop is more frequently used in Modelica as compared to '''while'''.

|-
|| 08:37
|| Let us discuss '''Arrays''' now.

|-
|| 08:40
||'''Arrays''' are used to represent '''multi-dimensional''' data.

|-
|| 08:44
||They can be constructed using '''vector''' notation.

|-
|| 08:48
|| '''Syntax''' for '''array''' declaration and '''indexing''' is as shown.

|-
|| 08:55
|| To understated more about '''array''' construction and '''indexing'''.

|-
|| 09:00
||Let us write a '''class''' named '''matrixAdder''' which adds '''myMatrix''' and '''adder matrices''' to give '''mySum'''. '''myMatrix''' and '''adder matrices''' are as shown.

|-
|| 09:14
|| Now, let me switch to '''OMEdit''' to demonstrate '''matrixAdder''' class.

|-
|| 09:19
||It is already open in '''OMEdit'''.

|-
|| 09:23
|| Click on '''matrixAdder''' tab.

|-
|| 09:26
||Open it in '''Text view'''.

|-
||09:29
|| '''myMatrix''' is a '''Real''' parameter array.

|-
|| 09:33
|| Numbers in square bracket represent size of this '''array'''.

|-
|| 09:39
||The size of first dimension is '''3'''.

|-
|| 09:42
||Similarly, the size of second dimension is '''2'''.

|-
|| 09:46
|| '''myMatrix''' array is constructed using three vectors of two elements each.

|-
|| 09:53
|| '''{1,2}''' represents the first vector.

|-
|| 09:57
|| '''{3,4}''' is the second one and

|-
|| 10:00
|| '''{5,6}}''' represents the third vector.

|-
|| 10:04
||Size of each of this vectors is equal to size of second dimension of this array.

|-
|| 10:11
||Hence, the size of second dimension of myMatrix is '''2'''.

|-
|| 10:16
||The number of vectors is equal to the size of first dimension. Hence, the size of first dimension is equal to '''3'''.

|-
|| 10:25
|| '''adder''' matrix is constructed in a similar fashion.

|-
|| 10:29
|| To add this two arrays or matrices we need to access elements from two dimensions.

|-
|| 10:35
||Hence '''a''' '''nested for''' loop is required.

|-
|| 10:40
|| This '''for''' loop runs through the first dimension.

|-
|| 10:44
|| Similarly this '''for''' loop runs through the second dimension.

|-
|| 10:49
||Let me scroll down a bit.

|-
|| 10:52
|| Corresponding elements of '''myMatrix''' and '''adder matrices''' are added to yield '''mySum'''

|-
|| 11:00
|| This statements represent the end of each '''for''' loop. The class is now complete.

|-
|| 11:07
|| Let me simulate it by clicking on '''Simulate''' button.

|-
|| 11:11
||Close the pop up window if it appears.

|-
|| 11:15
||Let me expand '''variables''' column.

|-
|| 11:18
||Select '''adder[1,1]''', '''myMatrix[1,1]''', and '''mySum[1,1]'''.

|-
|| 11:25
||Note that '''adder[1,1]''' plus '''myMatrix[1,1]''' gives '''mySum[1,1]''' which means that the result is accurate.

|-
|| 11:35
||Let me de-select them and delete the result.

|-
|| 11:40
|| Let me go back to the slides.

|-
|| 11:43
|| As an assignment: Write a function named '''vectorReversal''' to reverse the order of elements in a vector.

|-
|| 11:51
||Similarly write a function '''matrixReversal''' to reverse the order of elements in each row of a matrix.

|-
|| 12:00
|| Write '''functionTester''' class to test these two functions.

|-
|| 12:05
|| This brings us to the end of this tutorial.

|-
|| 12:09
|| Please watch the video available at following link: [http://spoken-tutorial.org/ org] /What\_is\_a\_Spoken\_Tutorial''' It summarises the '''Spoken Tutorial''' project.

|-
|| 12:15
|| We conducts workshops using spoken tutorials.Give certificates. Please contact us.

|-
|| 12:21
|| If you have questions related to this spoken tutorial, please visit the following website.

|-
|| 12:28
|| We coordinate coding of solved examples of popular books.

|-
|| 12:33
||We give honorarium and certificates to those who do this. Please visit the following website.

|-
|| 12:39
|| We help migrate commercial simulator labs to OpenModelica. Please visit the following website for more information.

|-
|| 12:48
|| Spoken Tutorial Project is funded by '''NMEICT, MHRD''', Government of India.

|-
|| 12:55
|| We thank the development team of '''OpenModelica''' for their support.

|-
|| 13:00
|| Thank you for joining me in this tutorial.

@@ Line 539: / Line 539: @@
 || 12:09
 || Please watch the video available at following link:
-http://spoken-tutorial.org/What_is_a_Spoken_Tutorial''' It summarizes the '''Spoken Tutorial''' project.
+'''http://spoken-tutorial.org/What_is_a_Spoken_Tutorial'''
 |-

OpenModelica/C2/Arrays-in-Modelica/English-timed - Revision history

Sandhya.np14 at 09:03, 20 August 2018

Sandhya.np14 at 09:01, 20 August 2018

Jyotisolanki: Created page with "{| border=1 ||''' Time ''' ||'''Narration''' |- || 00:01 || Welcome to the spoken tutorial on '''Arrays'''. |- || 00:05 || In this tutorial, we are going to learn: How to d..."