View source for Scilab/C4/Loading-and-saving-data-in-Xcos/English

'''Title of script''': Loading and saving data in Xcos

'''Author: Rupak Rokade and Utkarsh'''

'''Keywords: Xcos,TOWS_c, C_binary, workspace, read, write, data file, scilab'''

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! '''Visual Cue'''
! '''Narration'''
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'''Title Slide'''
| Hello and welcome to the Spoken Tutorial on “ '''Loading and saving data in Xcos'''”.
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'''Learning Objectives'''
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In this tutorial, we will learn how to:

<ul>
<li><blockquote><p>Save '''Xcos''' simulation data values to the '''workspace'''.</p></blockquote></li>
<li><blockquote><p>Read and write data in '''Xcos''' simulation using a '''C binary''' file</p></blockquote></li></ul>
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'''System Requirements'''
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To record this tutorial, I am using

<ul>
<li><blockquote><p>'''Ubuntu 18.04 OS''' and</p></blockquote></li>
<li><blockquote><p>'''Scilab 6.1.0 version'''</p></blockquote></li></ul>
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'''Pre-requisites'''
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To follow this tutorial, you should have

<ul>
<li><blockquote><p>Basic knowledge of '''Scilab and Xcos.'''</p></blockquote></li>
<li><blockquote><p>If not, for relevant tutorials please visit this website.</p></blockquote></li></ul>
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'''Code Files'''
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<ul>
<li><blockquote><p>The files used in this tutorial are provided in the '''Code files''' link.</p></blockquote></li>
<li><blockquote><p>Please download and extract the files.</p></blockquote></li>
<li><blockquote><p>Make a copy and then use them while practising.</p></blockquote></li></ul>
|-
| Cursor on the '''Untitled Xcos editing''' window.
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I have already opened the '''Xcos''' windows.

We can see two windows named '''Untitled Xcos''' and the '''Palette browser''' are opened'''.'''
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On the '''Untitled Xcos''' window,

Cursor on '''Toolbar''' &gt;&gt; Click on '''Open file''' option &gt;&gt; Click on '''SaveData.xcos''' &gt;&gt; Click on '''OK.'''
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Go to the '''Untitled Xcos''' window.

Click on the '''Open File''' icon on the '''Toolbar'''.

A window will appear.

Go to the '''Downloads''' folder and select the file '''SaveData.xcos'''.

Then click on the '''OK''' button.
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| Adjust the Window accordingly.
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Let me adjust the window.

I have already created this file for demonstration.
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On the '''SaveData.xcos''' window,

cursor on the '''SaveData.xcos''' window.
| This file has a simple '''Xcos''' simulation diagram.
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On the '''SaveData.xcos''' window,

Hover cursor on '''RAMP''' block.
| It uses the '''RAMP''' block to generate a '''Ramp''' signal.
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On the '''SaveData.xcos''' window,

Hover cursor on '''CSCOPE''' block.
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And the '''CSCOPE''' block to plot it.

Let us see how to record the generated Ramp signal.
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On the '''SaveData.xcos''' window,

cursor on the '''SaveData.xcos window'''
| First we will see how to push the values generated by the '''RAMP''' block to '''workspace.'''
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On '''palette browser''',

click on '''Sinks''' &gt;&gt; scroll down &gt;&gt; click on '''TOWS_c.'''
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Go to the '''palette browser''' window.

Click on the '''Sinks''' palette.

In the right panel, select the '''TOWS_c''' block. This is the '''To Workspace''' block.
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| As per narration
| '''Drag and Drop''' the '''TOWS_c''' block to the '''SaveData.xcos''' window'''.'''
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On the '''editing''' window,

Double click on the '''TOWS_c''' block.
| Double click on the '''TOWS_c''' block to configure its properties.
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On the '''Scilab Multiple Values Request''' Window of '''TOWS_c''' block,

Double click on the '''Size of Buffer.''' Text field to highlight it.
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The size of buffer is by default set to '''128.'''

This means that 128 values will be saved in the block .

If any more values are passed, the block will overwrite the previous values.
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On the '''Scilab Multiple Values Request''' Window of '''TOWS_c''' block,

Double click on the '''Variable Name''' text field to highlight it.
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The '''Variable Name''' is the name of the variable to which the values are saved.

By default it is set to '''A.'''
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On the '''Scilab Multiple Values Request''' Window of '''TOWS_c''' block,

Double click on the '''Inherit''' Text field to highlight it.

Click on the '''OK''' button at the bottom.
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'''Inherit''' is used to decide whether to take the event input or not.

By default Inherit is set to '''0''' which means it has to take event input.

Click on the '''OK''' button to close this window.
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On '''SaveData.xcos Window''',

Connect as per narration'''.'''
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Let us make the connections.

Select the '''black input port''' of the '''TOWS_c''' block.

Connect it to the line joining the '''RAMP''' and the '''CSCOPE''' block.
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On '''SaveData.xcos Window''',

Connect as per narration'''.'''
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Next, Select the '''red input port''' of the '''TOWS_c''' block.

Connect it to the line joining the '''CLOCK_c''' and the '''CSCOPE''' block.

Our file is ready for simulation.
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On the '''SaveData.xcos''' window,

Click on '''Start''' button on the toolbar &gt;&gt; click on '''OK''' button on the '''Warning message.'''
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Let us run this simulation by clicking on the '''Start''' Button on the '''toolbar'''.

An '''Warning message''' will appear.

Ignore the message and click on the '''OK''' button.
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On the '''Graphic''' window,

Hover cursor on the '''graph.'''

Close the '''Graphic''' window.
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We can see a straight line with slope 2.

Let’s close the graphic window.
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| Switch to '''workspace.'''
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Now let us look at the values.

Switch to the '''workspace'''.
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On the '''workspace''',

Type '''''A''''' &gt;&gt; press '''Enter.'''
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Let us execute the variable '''A'''.

Type '''A''' on the '''workspace''' and press '''Enter'''.
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On the '''workspace''' window,

Highlight '''variable A.'''

Highlight '''values.'''

Highlight '''time.'''
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'''A''' is a special variable.

We can either extract '''values''' from '''A''' or we can extract '''times''' from '''A.'''

Let us look at the values.
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On the '''workspace''' window,

Type '''''A.values''''' &gt;&gt; Press '''Enter.'''
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Type '''A.values''' on the '''workspace'''.

Press '''Enter.'''
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On the '''workspace''',

Scroll up to show all the values and Highlight them.
| These are all the values from the graph and are now saved in the workspace.
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On the '''workspace''',

hover cursor on a new line on the workspace.
| Now we need to save these values in a file so that we can share them.
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| Switch to '''SaveData.xcos''' window.
| Switch back to the '''SaveData.xcos''' window.
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On the '''palette browser''',

Click on '''Sinkss''' &gt;&gt; Click on '''WRITEC_f''' block.
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To save these values, we will use the '''WRITEC_f''' block.

Go to the '''palette browser''' window.

Click on the '''Sinks''' palette.

Click on the '''WRITEC_f''' block in the right panel.

This is the '''Write to C binary file''' block.
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| As per narration
| '''Drag and Drop''' the block on the '''SaveData.xcos''' window.
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On the '''SaveData.xcos''' window,

Double click on '''WRITEC_f''' block.
| Double click on the '''WRITEC_f''' block to configure its properties.
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On the '''Scilab Multiple Values Request''' Window of '''WRITEC_f''' block,

Double click on the '''Input Size''' Text field to highlight it.
| '''Input Size''' is the size of our input values.
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On the '''Scilab Multiple Values Request''' Window of '''WRITEC_f''' block,

Double click on the '''Output File Name''' Text field to highlight it &gt;&gt; Change it to '''''‘data’'''''
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'''Output File''' is the name of our output file.

I will name the output file as '''‘ data ‘'''.

If no file path is entered, the file will be saved in the '''Current working directory.'''
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On the '''Scilab Multiple Values Request''' Window of '''WRITEC_f''' block,

Double click on the '''Output Format''' Text field to highlight it &gt;&gt; Change it to ‘ '''d''' ’
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'''Output Format''' is the format of the output file.

By default it is '''‘ c ‘.''' That is, by default, values are saved as integers.

But, I want to save the values as '''double.''' So''',''' I will change it to '''‘d’.'''
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On the '''Scilab Multiple Values Request''' Window of '''WRITEC_f''' block,

Double click on the '''Buffer Size''' Text field to highlight it.
| '''Buffer Size''' is the size of the buffer.
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On '''SaveData.xcos Window''',

Connect as per narration'''.'''
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Let us make the connections.

Select the '''black input port''' of the '''WRITEC_f''' block.

Connect it to the line joining the '''RAMP''' and the '''CSCOPE''' block.
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On '''SaveData.xcos Window''',

Connect as per narration'''.'''
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Next, Select the '''red input port''' of the '''WRITEC_f''' block.

Connect it to the line joining the '''CLOCK_c''' and the '''CSCOPE''' block.

Our file is ready for simulation.
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On the '''SaveData.xcos''' window,

Click on '''Start''' button on the toolbar &gt;&gt; click on '''OK''' button on the Warning message.
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Let's run the simulation again by clicking on the '''Start''' Button on the '''toolbar.'''

A '''Warning message''' will appear. Ignore the message and click on the '''OK''' button.
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On the '''Graphic''' window,

Hover cursor on the '''graph.'''

'''Close''' the Graphic window.
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We can see the graph.

Let’s close the graphic window.
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| As per narration.
| Let's go to the location where we have saved the data file.
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On '''file manager window''',

Click on the '''data''' file once.
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We can see a file named '''‘ data ‘''' .

Since it is a binary encoded file we cannot simply read it.

We would need a special block to read this file.
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| Switch back to '''SaveData.xcos''' file
| Switch back to the '''SaveData.xcos''' window.
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On the '''SaveData.xcos''' window,

Cursor on '''Toolbar''' &gt;&gt; Click on '''Open file''' option &gt;&gt; Click on '''LoadData.xcos''' &gt;&gt; Click on '''OK'''
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Let us open the file '''LoadData.xcos'''

Click on the '''Open File''' icon on the '''Toolbar'''.

A window will appear.

Go to '''Downloads''' Folder and select the file '''LoadData.xcos'''.

Then click on the '''OK''' button.

We will use this file to read our data file.
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| Adjust the Window accordingly.
| Let me adjust the window.
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On the '''palette browser,'''

Click on '''Sources''' &gt;&gt; Click on '''READC_f''' block.
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We will use the '''READC_f''' block to read our values.

Go to the '''palette browser''' window.

Click on the '''Sources''' palette.

Click on '''READC_f''' Block in the right panel.

This is the '''Read from C Binary''' block.
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| As per narration
| '''Drag and Drop''' the block on the '''LoadData.xcos''' window.
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On the '''LoadData.xcos''' window,

Double click on '''READC_f''' block..
| Double click on the '''READC_f''' block to configure its properties'''.'''
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On the '''Scilab Multiple Values Request''' Window of '''READC_f''' block,

Double click on the '''Input File Name''' Text field to highlight it. &gt;&gt; Change it to '''''data'''''
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'''Input file''' name is the name and the path of your data file.

Since my data file was named '''data''' I will change it to '''data'''.
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On the '''Scilab Multiple Values Request''' Window of '''READC_f''' block,

Double click on the '''Input Format''' Text field to highlight it &gt;&gt; Change it to '''''d.'''''
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'''Input format''' is the format of the data file.

Since the format for my data file is '''double''' , I will change it to '''d'''.
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On the '''Scilab Multiple Values Request''' Window of '''READC_f''' block,

Double click on the '''Buffer Size''' Text field to highlight it.

Click the '''OK''' button .
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This is the buffer size.

Let’s close this window by clicking on the '''OK''' button.
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On '''LoadData.xcos Window''',

Connect as per narration'''.'''
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Let us make the connections.

Select the '''black output port''' of the '''READC_f''' block.

Connect it to the '''black input port''' of the '''CSCOPE''' block.
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On '''LoadData.xcos Window''',

Connect as per narration'''.'''
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Lastly, Select the '''red input port''' of the '''READC_f''' block.

Connect it to the line joining the '''CLOCK_C''' &amp; the '''CSCOPE''' block.
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On the '''LoadData.xcos''' window,

Click on '''Start''' button on the '''toolbar'''
| Let’s run this simulation again by clicking on the '''Start''' Button on the '''toolbar'''.
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On the '''Graphic''' Window,

Hover Cursor on the '''Graph.'''
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We have a similar graph to the one we had earlier without using the '''RAMP''' block.

This is because we have loaded the values from the data file.
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Show Slide:

'''Summary'''
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This brings us to the end of this tutorial. Let us summarise.

In this tutorial, we have learnt to:

<ul>
<li><blockquote><p>Save '''Xcos''' simulation data values to the '''workspace'''.</p></blockquote></li>
<li><blockquote><p>Read and write data in '''Xcos''' Simulation using a '''C binary''' file</p></blockquote></li></ul>
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Show Slide:

'''Assignment'''
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As an assignment,

Create two '''Xcos''' simulation files:

<ul>
<li><blockquote><p>Use the first for plotting a straight line with slope 3.</p></blockquote></li>
<li><blockquote><p>Push the values to the workspace and save them as a binary encoded file.</p></blockquote></li>
<li><blockquote><p>Create another '''Xcos''' simulation to plot a new graph of a straight line with slope 3.</p></blockquote></li>
<li><blockquote><p>Use only the saved data values.</p></blockquote></li></ul>
|-
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'''Answers for THIS Spoken Tutorial'''
| Please post your timed queries in this forum.
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Please post your general and technical queries on '''Scilab''' in this forum.

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'''Textbook Companion project.'''
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The FOSSEE team coordinates the Textbook Companion project.

We give Certificates and Honorarium to the contributors.

For more details, please visit this website.
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The FOSSEE team coordinates the Lab Migration project.

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| Show Slide: '''Acknowledgement'''
| Spoken Tutorial and FOSSEE projects are funded by the Ministry of Education, Government of India.
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| Show Slide: '''Thank you'''
|
This is Utkarsh Anand, FOSSEE intern 2021, IIT Bombay signing off.

Thanks for joining.
|}