Scilab/C2/Plotting-2D-graphs/English-timed

Time	Narration
00.00	Welcome to the spoken tutorial on Plotting 2D graphs with scilab.
00.04	Assuming that Scilab is installed on your computer, we will discuss plots in Scilab.
00.10	Scilab offers many ways to create and customize various types of 2D and 3D plots.
00.15	The several common charts Scilab can create are: x-y plots, contour plots, 3D plots, histograms, bar charts, etc...
00.24	Now open your Scilab console window.
00.28	I will use Plotting.sce file to cut and paste the commands.
00.34	In order to Plot, we need a set of points. Let us create a sequence of equally spaced points.
00.39	This can be done by the linspace command which creates a linearly equally spaced vector.
00.45	For Example
00.48	x is a row vector with 5 points linearly equally spaced between 1 and 10
00.57	Similarly y is a row vector with linearly equally spaced 5 points between 1 and 20
01.08	More information on linspace can be obtained from the Help documentation.
01.14	We will now plot a graph with the arguments x and y using the Plot function.
01.19	This is similar to the one used in matlab.
01.23	Plot x,y creates a graph of x verses y as you see.
01.31	Notice that the graphics window is labeled as '0'
01.36	We will open another graphic window using the xset function.
01.41	I will close this.
01.43	Cut the xset function, paste in scilab hit enter.
01.50	You will see a graphic window number 1.
01.54	Note that two arguments are passed to this function namely the window and 1.
02.03	The next graph will be plotted on this window.
02.06	For scilab plot 2d is the native function used to plot 2d graphs.
02.14	plot2d command plots a graph of x verses y as you see.
02.26	Notice that there is a third argument called style.
02.31	Style argument is optional.It is used to customize the appearance of the plot.
02.36	For positive values of style the curve is a plain with different colours like green for 3 in our case.
02.44	The default value of style is 1.
02.46	Try plotting graphs for negative values and see the difference in appearance yourself.
02.51	Also we can set the start points and end points for x and y axis by passing the fourth argument.
02.57	It is called rect. As you see,
03.07	We have x axis starting from 1 to 10 and y axis from 1 to 20.
03.14	The order of argument in the rect command is xmin, ymin, xmax and ymax.
03.24	Let us now learn about Title,Axis and Legends
03.28	To configure labels to the axis and title to the plot we can use the commands title, x label and ylabel.
03.38	I will cut this set of commands and paste in the console. Hit enter
03.45	You will see that the graph has been labeled x to the x axis, y to the y axis and the title of the graph is my title.
03.58	You may want to configure the title and axis of the plot in a single command instead of 3
04.04	For this purpose we use the xtitle command with all the 3 arguments.
04.11	I will cut this command paste in scilab enter.
04.18	Now you see that the x axis label is X axis , Y axis and the title is My title.
04.26	The clf() function that i am typing now will clear the graphic window as you see.
04.36	It is useful while plotting different graph on the same graphic window.
04.41	I will close this window.
04.44	Sometimes we need to compare two sets of data in the same plot, that is, one set of x data and two sets of y data.
04.51	Let us see an example for this I will scroll down
04.56	We will define the x axis points in a row vector x using the linspace command
05.03	Let us define a function
05.05	y1 = x square
05.07	plot x verses y1
05.10	define another function y2 = 2x square
05.15	plot x verses y2
05.17	We will also give label and title to our graph
05.22	Notice that we have additionally passed ”o-” and ”+ -” commands to the plot function, to change the appearance of the curve
05.33	These arguments are not a part of the plot2d function.
05.37	They can be used only with the plot function
05.41	I will copy these set of commands and paste in the scilab console.
05.49	You see the graph
05.51	Wouldn't it be of great help to know which curve is associated with which function?
05.56	This can be achieved using the legend command, as you see
06.08	"o-" curve represents function y1=x square and "+-" curve represents function y2=2*x^2 (y2=2x square)
06.19	I will close this graphic window
06.22	We will now discuss about plot2d demos and subplot function
06.28	Scilab provides demos for all its major functions.
06.31	Demos of plot2d can be viewed through the demonstration tab.
06.39	Click on Graphics, click 2d_3d plots and select a demo out of the various demos provided.
06.51	I will click on plot2d.
06.54	You will see the demo graph
06.55	The code for this graph can also be seen by clicking on the view code button here.
07.02	This link does not open in Mac OS but it works in windows and linux
07.07	Never the less in Mac the code can be viewed through the directory.
07.12	Let us go to the terminal.
07.15	Currently i am in demos directory of scilab 5.2 as shown.
07.21	The full path to this directory is shown here.
07.27	We will type ls to see the list of demos available, as you see here.
07.36	Then we will select the 2d_3d_plots directory and hit enter.
07.46	Type ls again to see the various demo code available in the sce files
07.55	we will view the code for the demo which we have seen earlier.
08.00	Type more plot2d.dem.sce and hit enter
08.11	Here you will see the code for the demo graph of plot2d function
08.18	I will close the terminal.
08.21	I will close the demo graph and the demo window
08.26	Similarly you can go through the other demos and explore scilab
08.29	Let us now discuss about Subplot function
08.33	The subplot() function divides the graphics window into a matrix of sub-windows.
08.37	To explain this function we will use demos for plotting 2D graphs in scilab.
08.43	For example, type plot 2d in your console and see the demo plot for this function
08.58	I will close this window.
09.00	The subplot command breaks the graphics window into a 2 by 2 matrix of sub-windows represented by the first two arguments in the subplot command.
09.10	The third argument denotes the current window in which the plot will be plotted
09.15	I will execute this whole set of commands by copying it to the scilab console
09.24	You can see 4 plots in a single plot window .
09.28	The plot obtained can be saved as a image on your computer
09.32	Click on the graphic window, go to File menu select export to .
09.39	Give a suitable title to your plot,
09.50	Select a destination folder to save your file.
09.54	Select the file format in which you want your image to appear.
09.59	I will select the JPEG format and Click Save.
10.05	Browse through the directory to open the image and verify yourself whether it has been saved or not.
10.11	This brings us to the end of this spoken tutorial on Plotting in Scilab.
10.15	There are many other functions in Scilab which will be covered in other spoken tutorials.
10.20	Keep watching the Scilab links.
10.22	Spoken Tutorials are part of the Talk to a Teacher project, supported by the National Mission on Education through ICT.
10.29	More information on the same is available on the following link
10.32	Thanks for joining. Good bye

Contributors and Content Editors

Gaurav, Krupali, PoojaMoolya, Sandhya.np14, Sneha