Sandhya.np14 at 06:25, 4 March 2015

2015-03-04T06:25:44Z

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Sandhya.np14 at 11:30, 3 March 2015

2015-03-03T11:30:03Z

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Gaurav at 05:46, 11 July 2014

2014-07-11T05:46:37Z

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PoojaMoolya: Created page with '{| Border=1 || Time || Narration |- | 00.01 | Welcome to the spoken tutorial on ''' “Calling user-defined functions in Xcos”''' |- | 00.07 | In this tutorial we will le…'

2014-03-19T11:10:53Z

Created page with '{| Border=1 || Time || Narration |- | 00.01 | Welcome to the spoken tutorial on ''' “Calling user-defined functions in Xcos”''' |- | 00.07 | In this tutorial we will le…'

New page

{| Border=1

|| Time

|| Narration

|-
| 00.01
| Welcome to the spoken tutorial on ''' “Calling user-defined functions in Xcos”'''

|-
| 00.07
| In this tutorial we will learn,

|-
|00.09
|To write a squaring function in '''Scilab'''

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|00.12
|To use the ''' scifunc''' block in ''' Xcos'''

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| 00.15
| To use MUX block to draw multiple plots

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|00.19
|To call functions having multiple inputs and outputs

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| 00.24
|''' Ubuntu''' 12.04 is the ''' operating system''' used with '''Scilab version 5.3.3 installed.'''

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| 00.32
| You should have Basic knowledge of ''' Scilab'''

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|00.35
|Basic knowledge of ''' Xcos'''

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| 00.38
| If not, for relevant tutorials please visit ''' spoken hyphen tutorial dot org'''

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| 00.44
| Start ''' Scilab''' on your computer.

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|00.47
|In the ''' Scilab''' console, type ''' editor''' and press ''' Enter'''

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|00.53
|Then type the following code

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|00.55

|function space ''' y ''' is equal to squareit open bracket a close bracket

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|01.07

|Press the enter key and type

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|01.10
|''' y''' is equal to '''a''' raise to 2

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| 01.14

|put a semicolon in the end

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| 01.17
|The function has one input variable ''' a''' and one output variable ''' y '''

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|01.24

|The name of the function is ''' squareit '''

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|01.27
|This function will do the job of squaring the variable ''' a.'''

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|01.31

|It will store the result in ''' y.'''

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|01.34

|Let us save this file in the desired directory.

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|01.38
|I will save this file with file name ''' squareit''' and extension ''' .sci '''

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| 01.44
|Here we are following the convention of saving functions in '''.sci''' format.

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|01.50

|Switch to the ''' Scilab''' console

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|01.53

| Now, type ''' Xcos''' and press '''Enter.'''

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|01.57

|Two windows will open

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| 01.59

|A ''' palette browser''' and an '''untitled Xcos''' window.

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| 02.04
|Now we will make the ''' Xcos''' diagram.

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|02.06
| This will access the function '''squareit''' created just now.

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|02.10
| This can be done by using '''scifunc''' block.

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| 02.14
|Switch to the ''' palette browser''' window

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| 02.17
|Click on the ''' User-Defined''' function in the pallet browser.

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| 02.21
|Locate the block '''scifunc_block_m''' in this section.

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| 02.27
|Drag and drop it in '''untitled Xcos''' window.

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|02.32
|I will zoom the untitled Xcos window for better view.

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| 02.36

|I will use the Zoom button as you see.

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| 02.40
|Now double click on the '''scifunc''' block to configure it.

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|02.44

|A window named ''' Scilab multiple values request''' will open

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| 02.49
| This window will allow you to change the number of input and output ports of the '''scifunc''' block.

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| 02.56

|Our function '''squareit''' has only one input and output variable.

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| 03.00

| 'Hence, we will keep the settings unchanged.

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| 03.03

| Click on Ok.

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|03.05

||A new '''Scilab input value request''' window will open.

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|03.09

|In the text box, type the function name along with input and output variables.
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| 03.14

|This function will be called by the scifunc block

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| 03.18

|In the text box available,

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| 03.20

|edit the default function name.

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| 03.22

|Type '''y1''' equal to '''squareit''' open bracket '''u1''' close the bracket

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| 03.31

|Note that, here the input and output variables are '''u1''' and '''y1''' respectively.

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| 03.37

|These should be strictly in '''u''' and '''y''' form and not as per the variable names used in the actual function.

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| 03.45

|Cick on '''OK.'''

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| 03.47

|Another '''Scilab input value request''' window will open.

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| 03.51

|Keep clicking on '''Ok''' in the subsequent 3 windows that will appear.

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|03.56

|The '''scifunc''' block is now configured.

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| 04.00

|Next we will include a '''sinusoid''' generator block.

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| 04.04

| In the '''palette browser''' window, click on '''Sources section. '''

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| 04.08

|Drag and drop the '''Sinusoid Generator''' block in '''untitled Xcos''' window.

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| 04.14

|Place the block towards the left of the '''scifunc''' block for convenience.

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| 04.20
| Now we need a block to plot the output variable.

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| 04.23
|'In the '''palette browser window,''' click on '''Sinks''' section.

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| 04.29
|Drag and drop the '''CScope''' block in the '''untitled Xcos''' window.

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| 04.34

| Place the block towards the right of the '''scifunc''' block

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| 04.38

| Place it away from scifunc block, for convenience.

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| 04.43

|Notice that the '''CScope''' block has a red input port.

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| 04.47

| This is an event input

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| 04.49

|we need an event generator block.

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| 04.52

|In the ''' palette browser window,''' click on '''Sources''' section.

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| 04.57

|Drag and drop the clock underscore c block in the '''untitled Xcos''' window.

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| 05.05

|Place it above the '''CScope''' block.

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| 05.08

|Notice that the '''CScope''' block has only one input port.

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| 05.13

|But we want to plot both the input and output variables in a single plot window.

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| 05.18

|Hence, we need a multiplexer block,

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| 05.22

|This block will multiplex two inputs and generate output on one output port.

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| 05.28

|In the ''' palette browser window,''' click on '''Signal Routing''' section.

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| 05.33

|Drag and drop the '''MUX''' block in the '''untitled Xcos''' window.

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| 05.39

|Place the block between the '''scifunc''' block and '''CScope''' block.

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| 05.43

|Let me resize and realign the '''Mux block'''

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| 05.47

|Now let us connect the blocks together.

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| 05.51

|Connect the output port of '''Sinusoid generator''' block to the input port of '''scifunc''' block

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| 05.57

|Now connect the output port of '''scifunc''' block to the lower input port of the '''MUX.'''

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| 06.04

|Connect the output port of '''MUX''' block to the input port of '''CScope''' block.

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| 06.10

|Connect the output port of clock underscore c block to the event input port of '''CScope''' block.
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| 06.19

|We also have to plot '''sine''' input.

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| 06.22

|We have to connect the '''Sinusoid generator''' block to the '''MUX.'''

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| 06.26

|Click on the upper input port of the '''MUX''' block.

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| 06.30

|Then without releasing, move your mouse pointer towards the link between the ''' Sinusoid generator''' block and '''scifunc''' block.

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| 06.39

|To bend the link, release the mouse button or click at places

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| 06.44

|As you bring the pointer on the link, the link turns green.

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| 06.49

|Release the mouse button or click once to create a link between these two blocks.

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| 06.55

|Now let us see the configuration of other blocks

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| 06.59

| We can change the '''frequency, magnitude''' and '''phase''' of the '''sinusoid generator''' block.

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| 07.04

|To do this, double click on the '''Sinusoid''' generator block.

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| 07.09

|The configuration window will open.

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| 07.11

|We will keep the '''magnitude''' and '''frequency''' as 1 and ''' phase''' as 0

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| 07.18

|Click on ''' Ok''' to close the configuration window.

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| 07.21

|Now let us configure the '''CScope''' block.

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| 07.25

|Double click on the '''CScope''' block to open its configuration window.

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| 07.30

|Change the ''' Ymin''' parameter to minus 2 and '''Ymax''' parameter to 2

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| 07.37

|Change the '''Refresh period''' value to 10.

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| 07.41

|Make a mental note of this value.

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| 07.44

|Change the '''buffer size''' value to 2 .

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| 07.47

|click on '''OK'''

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| 07.50

|Now let us configure the '''CLOCK_c''' block

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| 07.54

|Double click on the block to open its configuration window.

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| 07.58

|Keep the value of ''' Period''' as 0.1

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| 08.02

|Change the ''' Initialisation Time''' to be 0.

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| 08.06

|Click on OK

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| 08.08

|Now let us change the '''Simulation''' parameters.

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| 08.12

|On the menu bar of the '''untitled Xcos''' window click on the '''Simulation tab.'''

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| 08.17

|Now click on ''' Setup from the drop down menu.'''

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| 08.22

|Change the ''' Final Integration time''' to match the '''Refresh period''' of '''CScope''' block.

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| 08.28

|The value of '''Refresh period''' was 10.

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| 08.32

|Hence, put the value of '''Final integration''' time as 10.

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| 08.36

|Click on '''OK'''

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| 08.38

|Now, click on '''File''' and then click on '''Save''' to save the '''Xcos''' diagram.

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| 08.44

|Choose a desired directory to save the '''Xcos''' diagram.

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| 08.48

|However, it is advised to save it in the folder where you have saved the '''squareit.sci''' file.

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| 08.56

|Click on OK

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| 08.58

|Note that the '''scifunc''' block will call the ''' squareit''' function.

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| 09.02

|This means that we should first load the ''' squareit''' function before we execute the xcos diagram.

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| 09.09

|Switch to the ''' Scilab editor''' window, which has the '''squareit.sci''' file open.

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| 09.16

|Click on the '''Execute''' button available on the '''menu bar''' of the editor.

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| 09.21

|This will load the '''squareit''' function.

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| 09.24

|Now we can execute the '''Xcos''' diagram.

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| 09.28

|Open the Xcos diagram file

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| 09.31

|Click on the '''Start''' button available on the '''menu bar''' of '''Xcos''' window

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| 09.37

|A graphic window will appear.

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| 09.39

|This window will have two plots.

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| 09.42
|Input '''sine wave''' in black color and output '''sine wave''' in green color.

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| 09.47

|Notice that the squaring function implemented in the '''squareit''' function, has indeed squared the input sine wave.

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| 09.55

|Hence, the output '''sine''' wave has been shifted to the positive axis.

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| 10.00

|Close the plot window

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| 10.02

|Now, let us see how to edit the scifunc block to call a function which has more than one input and output variables.

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| 10.10

|Switch to '''scilab''' editor window.

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| 10.13

|Edit the '''squareit''' function to have two input and output variables.

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| 10.19

|Edit the output variable as open square bracket y comma z close the square bracket .

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| 10.28

|Edit the input variables as open bracket '''a''' comma '''b''' close bracket

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| 10.36

|We will change the function to shift the squared output by 1 unit.

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| 10.41

|Edit the main function line as

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| 10.44

|'''y''' is equal to '''b''' plus '''a''' raise to two put a semicolon in the end

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| 10.51

|Also generate an output whose amplitude will be half of the input.

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| 10.56

|Go to next line by pressing enter key and type

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| 11.01

|'''z''' is equal to 0.5 multiplied by a put a semicolon in the end

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| 11.10

|Now save the file

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| 11.12

| switch to the xcos window

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| 11.15

|Double click on the '''scifunc''' block to configure it.

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| 11.19

|In the ''' input port size field,''' put a semi colon after 1 comma 1 and type 1 comma one again

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| 11.27

|Similarly, in the output port size field, put a semi colon after 1 comma 1 and type 1 comma 1 again

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| 11.36

|Click on Ok

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| 11.38

|A new '''Scilab input value request''' window will open.

|-

| 11.41

|In the text box,

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| 11.43

|Put a comma after y1 and type y2.

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| 11.48

|Put y1 and y2 in square brackets

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| 11.52

|Now put a comma after '''u1''' and type '''u2'''

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| 11.57

|Click on OK

|-

| 11.59

|Another '''Scilab input value request''' window will open.

|-

| 12.03

|Keep clicking on '''Ok''' in the subsequent 3 windows that will appear.

|-

| 12.08

|The '''scifunc''' block is now configured.

|-

| 12.11

|Let me realign the scifunc block
|-

| 12.14

|Switch to the ''' palette browser''' window.

|-

| 12.17

|In the '''sources''' section, drag and drop the Constant underscore m block in the xcos window.

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| 12.24

|Place it below the sinusoid generator block.

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| 12.28

|Connect the ''' Constant underscore m''' block to the lower input of the '''scifunc''' block

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| 12.36

|The default value of this block is 1.

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| 12.39

|Keep it unchanged.

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| 12.41

|Double click on the '''MUX''' block.

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| 12.44

|Change the ''' input port size''' to 3

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| 12.47

|Click on '''OK'''

|-

| 12.48

|Let me resize the '''MUX''' block and I will connect '''MUX''' and '''CSCOPE''' block properly.

|-

| 12.59

|Connect the lower output port of the '''scifunc''' block to the lower input port of '''MUX''' block

|-

| 13.07

|Click on '''File''' and choose '''Save''' to save the xcos file.

|-

| 13.12

|Switch to the '''Scilab editor''' which has the '''squareit.sci''' file open.

|-

| 13.18

|Click on the '''Execute''' button available on the '''menu bar''' of the editor.

|-

| 13.23

|This will load the '''squareit''' function.

|-

| 13.26

|Now we can execute the '''Xcos''' diagram.

|-

| 13.30

|Click on the '''Start''' button available on the '''menu bar''' of the '''Xcos''' window.

|-

| 13.35

|A graphic window will appear.

|-

| 13.38

|This window will have three plots.

|-

| 13.40

|Input '''sine wave''' in black color,

|-

| 13.43

|output ''' sine wave''' in green color and
|-

| 13.45

| amplitude scaled input in red colour

|-

| 13.49

|Notice that the function has indeed squared the input '''sine wave''' and also shifted it by an offset of 1 unit, which is as expected.

|-

| 13.59

|We also get the amplitude scaled of the input '''sine wave,''' as expected

|-

| 14.05

|Close the plot window

|-

| 14.08

|Now let us summarize.

|-

| 14.10

|In this tutorial we learnt,

|-

| 14.12

|To write a squaring function in '''Scilab'''

|-

| 14.15

|To use the '''scifunc''' block in '''Xcos '''

|-

| 14.19

|To use '''MUX ''' block to draw multiple plots

|-

| 14.22

|To call functions having multiple input and output

|-
|14.26
| Watch the video available at the following link

|-

| 14.29

| It summarises the Spoken Tutorial project

|-

|14.33

||If you do not have good bandwidth, you can download and watch it

|-

|14.37

||The spoken tutorial project Team

|-

|14.40

||Conducts workshops using spoken tutorials

|-

|14.43

||Gives certificates for those who pass an online test

|-

|14.47

||For more details, please write to contact@spoken-tutorial.org

|-

|14.53

|Spoken Tutorial Project is a part of Talk to a Teacher project

|-

| 14.57

| It is supported by the National Mission on Eduction through ICT, MHRD, Government of India.
|-

| 15.05

|More information on this mission is available at spoken-tutorial.org/NMEICT-Intro

|-

|15.15

| Thank you for joining .Hope you found this tutorial useful

|-

| 15.19

|This is Anuradha Amruthkar from IIT Bombay signing off.

Scilab/C4/Calling-User-Defined-Functions-in-XCOS/English-timed - Revision history

Sandhya.np14 at 06:25, 4 March 2015

Sandhya.np14 at 11:30, 3 March 2015

Gaurav at 05:46, 11 July 2014

PoojaMoolya: Created page with '{| Border=1 || Time || Narration |- | 00.01 | Welcome to the spoken tutorial on ''' “Calling user-defined functions in Xcos”''' |- | 00.07 | In this tutorial we will le…'