Sandhya.np14 at 11:40, 20 August 2018

2018-08-20T11:40:22Z

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

2017-10-05T09:32:05Z

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

New page

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

|-
|| 00:01
|| Welcome to the Spoken Tutorial on '''Packages'''.

|-
||00:05
|| In this tutorial, we are going to learn: How to create a '''package''' of '''classes''' in '''Modelica'''.

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||00:12
||How to reference '''classes''' in a '''package'''.

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||00:16
||How to import a '''package''' and How to use '''Modelica Library'''.

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|| 00:22
|| To record this tutorial, I am using : '''OpenModelica 1.9.2''' and '''Ubuntu''' Operating System version '''14.04''' and '''gedit'''.

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||00:35
||'''Windows''' users may use '''Notepad''' or any other text editor instead of '''gedit'''.

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|| 00:42
|| To understand and practice this tutorial, you need Knowledge of '''class''' and '''type definition''' in '''Modelica'''

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||00:51
|| Prerequisite tutorials are mentioned on our website. Please go through them.

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|| 00:56
|| A '''Package''' is a specialized '''class''' in '''Modelica'''.

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||01:01
||It is a collection of '''classes'''.

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||01:04
||It can be stored as a '''single file''' or a '''directory'''.

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||01:08
||We will first learn about '''single file storage'''.

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|| 01:12
|| In '''single file storage''' all '''classes''' belonging to a '''package''' are written in a '''single file'''.

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||01:20
||It is not recommended as it may get lengthy in a few cases.

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|| 01:24
|| Now let me switch to '''OMEdit''' to demonstrate '''single file storage''' for a '''package'''.

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|| 01:31
|| Please download and save all the files available on our website.

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|| 01:36
||You may see that there is a file and a folder bearing the name '''spokenTutorialExamples'''.

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||01:43
||Please download both of them.

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|| 01:46
|| Now, let me open the necessary files in '''OMEdit'''.

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||01:51
||'''Press Ctrl + O'''.

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||01:54
||Go to the appropriate location on your system and select '''spokenTutorialExamples.mo''',

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||02:02
|| '''bouncingBallWithUserTypes.mo''' and '''bouncingBallWithImport'''.

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|| 02:08
||You may also open each of them individually.

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|| 02:12
||Note that I have not selected '''spokenTutorialExamples''' folder.

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|| 02:17
||We shall discuss more about it when we look at directory storage.

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||02:23
||Click on '''Open'''.

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|| 02:25
||You may see that '''spokenTutorialExamples''' package is now seen in '''Libraries Browser'''.

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|| 02:32
|| Double click on '''spokenTutorialExamples''' icon.

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|| 02:37
|| Switch to '''Text View''' if the file opens in '''Icon/Diagram View'''.

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|| 02:42
|| Now let me discuss '''spokenTutorialExamples'''

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|| 02:47
||First line defines the name of a '''package'''.

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|| 02:51
||Evidently, name of this package is '''spokenTutorialExamples'''.

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||02:56
|| This package consists of '''freefall class''' '''bouncingBall''' model and '''bouncingBallWithUserTypes''' models.

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|| 03:08
|| '''end statement''' defines where the package ends.

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|| 03:13
|| We have viewed all '''classes''' and '''models''' of this package at one place.

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|| 03:19
||Now, let us learn how to view individual ''classes'' in a package.

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|| 03:24
|| Click on the (+) button besides '''spokenTutorialExamples''' icon in '''Libraries Browser'''.

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|| 03:31
||This displays the names of '''classes''' present in this package.

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|| 03:36
|| Double-click on '''freeFall''' in '''Libraries Browser'''.

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|| 03:40
||'''freeFall class''' has now opened.

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|| 03:43
||Individual '''classes''' of a package may be simulated.

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|| 03:47
||But the package itself can not be simulated.

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|| 03:52
|| Let me go back to '''spokenTutorialExamples''' tab.

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|| 03:57
|| Note that '''Simulate''' button doesn’t appear in the toolbar which indicates that this package cannot be simulated.

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|| 04:06
|| Now let me unload '''spokenTutorialExamples''' from OMEdit.

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|| 04:12
||Do a right-click and select '''unload'''. Select '''Yes'''.

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|| 04:18
||This is done so as to avoid conflict when demonstrating directory storage.

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|| 04:24
|| Now let me go back to the slides.

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|| 04:27
|| In '''Directory storage classes''' are stored in separate files.

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|| 04:32
||Name of directory is same as that of the package.

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|| 04:37
||A file named '''package.mo''' is to be included in the directory and Each '''class''' starts with a '''within statement'''.

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|| 04:47
|| Now, let me demonstrate the folder '''spokenTutorialExamples''' that you’ve downloaded.

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|| 04:54
||Note that this folder represents the same package as that we have already discussed.

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|| 05:02
|| Let me demonstrate the file structure of this folder.

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|| 05:06
||Go to the location where you saved the downloaded files on your system.

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|| 05:12
|| Double-click on '''spokenTutorialExamples''' folder.

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|| 05:17
||Notice that the folder has following files: '''package.mo''', '''freeFall.mo''', '''bouncingBallWithUserTypes''' and '''bouncingBall'''.

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|| 05:30
||We shall understand more about directory storage using both '''OMEdit''' and '''gedit'''.

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|| 05:38
|| Note that '''package.mo''' indicates that this folder represents a package.

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|| 05:45
||Without this file, the folder doesn’t represent a '''Modelica package'''.

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|| 05:51
|| Now, let me switch to '''OMEdit''' to demonstrate directory storage.

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|| 05:57
||Press '''Ctrl + O'''.

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|| 05:59
||Navigate to the '''spokenTutorialExamples''' folder that you have downloaded.

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|| 06:05
||Select '''package.mo''' from this folder and click on '''Open'''.

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||06:11
|| '''spokenTutorialExamples''' package can now be seen in '''Libraries Browser'''.

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|| 06:17
||Double-click on '''spokenTutorialExamples''' icon.

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|| 06:22
|| Open the package in '''Text View''' if it opens in either '''Icon/Diagram View'''.

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||06:27
|| If you scroll down, you may notice that this package is the same as that we have seen in '''single file storage'''.

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|| 06:36
|| The difference between single file and directory storage can only be understood when we open this '''package''' using a text editor like '''gedit'''.

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|| 06:47
||You may use '''Notepad''' or any other text editor if you are using '''Windows'''.

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|| 06:53
|| Now let me unload '''spokenTutorialExamples''' package from 'OMEdit'''.

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||06:59
|| Switch to '''spokenTutorialExamples''' folder and open all the files using '''gedit'''.

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|| 07:08
||Now all the files are open in '''gedit'''.

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|| 07:13
||Let us take a look at '''package.mo''' first.

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|| 07:17
|| '''within statement''' indicates that this file represents a '''package'''.

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|| 07:21
|| Name of this package is '''spokenTutorialExamples'''.

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|| 07:25
||Note that the name of folder was '''spokenTutorialExamples''' as well.

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||07:31
|| '''package.mo''' file can only contain the '''within statement''' and '''package''' declaration.

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|| 07:38
|| Let me switch to '''freeFall''' tab.

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|| 07:41
|| This '''within statement''' indicates that '''freefall class''' belongs to '''spokenTutorialExamples''' package.

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|| 07:49
||Rest of this file has information specific to '''freeFall class'''.

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|| 07:54
|| You may see that other models in this package namely '''bouncingBallWithUserTypes''' and '''bouncingBall''' follow a similar syntax as well.

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|| 08:04
||But, we didn’t observe '''within statement''' when we opened the package in '''OMEdit'''.

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|| 08:11
||This indicates that '''within statement''' helps '''OMEdit''' recognize the file structure.

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|| 08:17
||Hence, it is omitted by '''OMEdit''' while displaying the '''package'''.

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|| 08:22
|| Let me go back to the slides.

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|| 08:25
|| We shall now understand more about '''Modelica Library'''.

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|| 08:29
||'''Modelica Library''' is an open-source package.

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|| 08:33
||'''OMEdit''' automatically loads it for every session.

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|| 08:38
||It can be seen in '''Libraries Browser'''.

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|| 08:41
||It has '''classes''' from '''mechanical, electrical''' and '''thermal''' domains.

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|| 08:46
||'''Classes''' of this library can be referenced and used.

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|| 08:51
|| Now let me switch to '''OMEdit''' to demonstrate '''Modelica Library'''.

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|| 08:57
|| Locate '''Modelica''' icon in '''Libraries Browser''' and expand it.

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|| 09:03
||Note that '''Modelica Library''' has packages named '''Blocks, Complex Blocks''' etc.

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|| 09:10
||You may note that a package may further contain packages as well as is evident here. Of special mention, is the '''SIunits''' package.

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|| 09:22
||Expand it.

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|| 09:25
|| This package has type definitions for physical quantities like '''Angle, Length, Position''' etc.

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|| 09:32
||We shall see how to use these type definitions using '''bouncingBallWithImport class'''.

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|| 09:39
||Compress '''SIunits'''.

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|| 09:42
|| And double-click on '''bouncingBallWithImport''' and '''bouncingBallWithUserTypes'''.

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|| 09:49
|| Let me shift '''OMEdit''' window to the left for better visibility.

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|| 09:55
|| We shall first look at '''bouncingBallWithUserTypes'''.

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|| 09:59
||We have learnt about this model in the prerequisite tutorials.

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|| 10:03
|| This model has type definitions named '''Length''' and '''Velocity'''.

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|| 10:09
||We can instead use the type definition in '''SIunits''' instead of defining them explicitly in every model.

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|| 10:18
||We shall see how to do that using '''bouncingBallWithImport''' model.

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|| 10:23
|| Let me switch to '''bouncingBallWithImport'''.

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||10:27
|| A '''class''' in a package is referenced to using '''dot'''.

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|| 10:32
||'''Modelica.SIunits''' refers to '''SIunits''' package which belongs to '''Modelica''' library.

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||10:39
|| Variable '''h''' is declared to be of '''Length''' type which is defined in '''SIunits''' package.

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||10:47
|| Similarly, variable '''v''' is declared to be of '''Velocity''' type which is defined in '''SIunits''' package.

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|| 10:56
|| Note that parameters '''radius''' and '''g''' are declared in a similar fashion.

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|| 11:03
||Now let me '''Simulate''' this model.

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|| 11:07
||Click on '''Simulate''' button in the toolbar.

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|| 11:10
||Close the pop up window.

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|| 11:13
||Select '''h''' in the '''Variables Browser'''.

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||11:17
|| Note that the plot obtained is similar to the one seen in the case of'''bouncingBallWithUserTypes'''.

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|| 11:25
||let me de-select '''h'''. Delete the result. Switch to '''Modeling''' perspective.

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|| 11:33
|| It is tedious to use the full name of a class every time.

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|| 11:38
||This can be simplified using '''import statement'''.

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|| 11:42
||Now, we shall type a few '''statements''' that show the use of '''import'''.

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|| 11:48
||The '''statements''' to be typed are provided in a text file named '''import-statements.txt'''.

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|| 11:56
||Go to the location where you saved it on your system.

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|| 12:01
||Double-click on '''import-statements.txt'''. '''Windows''' users may use '''Notepad''' to open this file.

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||12:11
|| The file is now open in '''gedit'''.

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|| 12:14
||Copy all the statements using '''Ctrl+C''' or by doing right-click.

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|| 12:21
|| Switch to '''OMEdit'''.

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|| 12:23
||Paste all the '''statements''' at the beginning of the model.

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|| 12:28
|| Delete the '''declaration statements''' for '''Length''' and '''Velocity,''' which have been defined before.

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|| 12:36
||Delete the extra spaces.

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|| 12:39
||Save this model by pressing '''Ctrl + S'''.

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|| 12:43
||Now the model is complete and ready for simulation.

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|| 12:48
|| Click on '''Simulate''' button to simulate it.

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|| 12:52
||Close the pop up window.

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|| 12:54
|| Select '''h''' in the '''Variables Browser'''.

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|| 12:58
||Note that the plot is same as in previous case.

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|| 13:03
||De-select '''h''' and delete the result.

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|| 13:07
||Switch to '''Modeling''' perspective.

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||13:10
|| Now let us now try to understand the '''import''' statements.

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|| 13:15
||Using the '''import statements''', '''Modelica''' looks up for '''Length''' and '''Velocity''' type definitions using the path mentioned here.

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|| 13:25
||This saves the trouble of referring to the package every time.

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|| 13:30
||A detailed discussion of '''lookup rules''' is beyond the scope of this tutorial.

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|| 13:36
|| Now let us see how we can replace these two '''import statements''' by a single '''import statement'''.Delete the two '''statements'''.

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||13:47
|| And type '''import (space) Modelica (dot) SIunits (dot) asterisk (semicolon)'''

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|| 13:58
||Save this model by pressing '''Ctrl + S'''

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|| 14:02
|| This '''statement''' is known as a '''wild-card import'''.

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|| 14:06
||This way, any '''class''' from '''SIunits''' may be accessed without explicitly mentioning it.

|-
|| 14:14
|| Now let me '''Simulate''' this model.

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|| 14:17
||Click on '''Simulate''' button.

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|| 14:20
||Close the pop up window.

|-
|| 14:22
|| Select '''h''' in the '''Variables Browser'''.

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|| 14:25
||You may notice the similarity of plot once again.

|-
|| 14:29
||De-select '''h''' and delete the result.

|-
||14:32
|| Go back to '''Modeling perspective'''.

|-
|| 14:35
|| Now let me switch to the slides.

|-
|| 14:38
||As an assignment, Declare variable '''h''' and '''v''' of '''freeFall class''' as '''Length''' and '''Velocity''' types respectively.

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|| 14:47
||These type definitions can be found in '''SIunits''' package of '''Modelica''' library.

|-
|| 14:54
|| This brings us to the end of this tutorial.

|-
||14:58
|| Watch the video available at the link shown below: ][http://spoken-tutorial.org/ org] /What\_is\_a\_Spoken\_Tutorial

|-
|| 15:02
||It summarises the '''Spoken Tutorial project'''.

|-
|| 15:05
||If you have questions in this '''Spoken Tutorial''', please visit the website shown.

|-
||15:11
|| We coordinate coding of solved examples from popular books.

|-
|| 15:15
||We give honorarium to contributors. Please visit our website.

|-
|| 15:21
|| We help migrate labs from commercial simulators to '''OpenModelica'''.

|-
|| 15:26
||Please visit the following website.

|-
|| 15:29
|| '''Spoken Tutorial Project''' is supported by '''NMEICT, MHRD''' Government of India.

|-
|| 15:36
|| We thank the development team of '''OpenModelica''' for their support.

|-
|| 15:41
|| I would like to thank you for joining me in this tutorial.

Good bye.

OpenModelica/C3/Modelica-Packages/English-timed - Revision history

Sandhya.np14 at 11:40, 20 August 2018

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