Gnuplot/C2/Generate-3D-plots-and-surfaces/English

Visual Cue	Narration
Slide Number 1 Title Slide Generate 3D plot and surfaces	Welcome to the tutorial on Generate 3D plot and surfaces
Slide Number 2 Learning Objectives	In this tutorial we will learn, Generate 3D plot with splot command Format surface properties Change viewing angle and rotate view Color the two sides of surfaces differently
Slide Number 3 Learning Objectives	* Make graph via script Run and edit script to change graph Draw a sphere Change surface color of sphere Generate heat map
Slide Number 4 System and Software Requirement	Debian Linux 9.3 Gedit text editor 3.22.0 and gnuplot 5.2.5
Slide Number 5 Pre-requisites	To follow this tutorial, learners must be familiar with, Basic computer and internet skills Concept of graphing and College level Mathematics skills
ctrl+alt+T >gnuplot	Please open a terminal by pressing control alt t keys together A terminal opens Please open gnuplot from the terminal Type gnuplot in prompt to open gnuplot
clear screen	I will also clear the screen for clarity in video.
	We will plot the function, cos x cos y to form a surface. Besides x and y axes, the third axis is the value of the function in the plot.
	Command for 3D plot is splot
splot cos(x)*cos(y)	Hence, we will enter command splot space cos x times cos y
	Make sure x and y are in parenthesis. This generates a 3D plot.
Rotate the graph	Hold down left mouse key and turn around and rotate the plot to your desire.
Zoom into graph	Zoom in slightly into graph to see a wavy surface. Notice the surface is plotted in a wide mesh style.
	Let's change some of the surface and graph properties. Next, we will color both sides of the surface differently.
>set hidden3d >replot	The required command for this is set space hidden3d Let's type it. Replot to see the changed colors.
	Now notice the hidden surface is colored green and the top surface is purple.
>set isosamples 50,50	Enter command, set space isosamples space 50 comma 50
>replot	Replot to notice a finer mesh defining the surface.
Rotate the surface	To rotate, hold down left mouse key and move to your desired viewing angle
Close graph	Notice, the angle change in the top of the graphic window. Next, close the graphic window. We will write a script to draw a sphere in gnuplot using a text editor.
Slide number 6 Polar coordinates and sphere	Equation of a sphere with radius R, centered at x0,y0 and z0 is x square plus y square plus z square plus is equal to R square Here r is the radius of the square Such functions can be plotted in polar co-ordinates.
	We will practice to write scripts in a text file. Then run the script file to plot a graph. We can edit the script file to make any required changes in the graph.
Click on Search your computer and online resources	Click on Search your computer and online resources icon
In search form type terminal and press enter	In search form type gedit and press enter to open gedit
	I will use gedit text editor, windows users may use notepad software.
	Let's enter a comment on first line. Comment starts with a hash.
# my first 3D plot and press enter	I will type # my first 3D plot and press enter to start to start newline
	Next, please type the commands as seen
> set parametric	First set to parametric mode
>set angle degree	Then set angle to degree
>set urange [0:360] >set vrange [0:360]	Set u and v range
>set isosample 50,50	Set isosamples to make a fine mesh
>set ticslevel 0	Set tic level to zero.
>r=1	I will set the radius to one.
Highlight >splot r*cos(u)*cos(v),r*sin(u)*cos(v),r*sin(v)	Next splot the function for sphere Pause the video if necessary, and explore more.
Ctrl s	Press crtl s to save
Give file name – sphere.dem in desktop folder click on save	A dialogue box opens. I will save the file in Desktop folder with name sphere.dem Click on Save
Close gedit, go to terminal	Minimize gedit. Go back to the terminal where gnuplot was open If you had closed gnuplot, please open gnuplot again
>cd “~/Desktop”	On gnuplot prompt change directory to desktop Use commands as seen on the screen Let's run the script to generate a sphere.
>load 'sphere.dem'	Type load space within single quotes sphere.dem
	A plot of a sphere centered at zero, zero, zero with radius one appear on the screen Next, say I want to change the sphere to blue color
Go back to gedit script	Go back to the gedit window to edit the script. If you had closed it, please open the script file to edit.
Add lc rgb 'red' in the end of splot command	Add lc space rgb space within single quotes blue
Save file	Save the changes in the script file
Go to gnuplot window	Come back to gnuplot and load the script file again as before
>load 'sphere.dem' Next, let's try a heatmap with pm3d command
Highlight and delete, lc rgb blue	Go back to the script in gedit Delete the lc space rgb space blue part This specified blue color as we saw in the graph
Type with pm3d	Instead type in with space pm3d to generate surface with heatmap
Save script, minimize edit, go to gnuplot	Save the script file, minimize gedit and go to gnuplot
Highlight, >load 'sphere.dem'	Load the sphere.dem script again
Hover mouse on heat map guide	Notice the heatmap in the sphere Notice the color ranges and the map guide is also visible Values in range 1 to 0.8 are yellow and minus 0.8 to minus 1 is deep purple.
	Via scripts, we can generate and make changes to graphs easily. Similar scripts are available in gnuplot demo website.
	Pause the video if required. Practice and familiarize with commands and styles.
Slide Number 7 Summary	To summarize, in this tutorial, we learned to Generated 3D graph with splot command Formatted 3D plot Changed viewing angle and rotate view Colored 2 surfaces of plot differently
Slide Number 8 Summary	* Plotted a sphere and formatted color Wrote and modified script, ran the script to generate plot and Learned to generate heat map
Slide Number 9 Assignment	For assignment, plot the following, Plot 5 spheres in the graph with radius 0.5, 1, 2, 3 and 4 Center them differently Hint: To plot more than one function, separate them using comma sign
Slide Number 10 Assignment	If you like to program, you may use a for loop If sphere is centered at x1, y1,z1 equation takes the form as seen on the slide
Slide Number 11 Spoken Tutorial Project	This video summarises the Spoken Tutorial Project Please download and watch it.
Slide Number 12 Spoken Tutorial workshops*	We conduct workshops and give certificates. Please write to us.
Slide Number 13 Forum for specific questions:	Post your timed queries in the forum.
Slide Number 14 Acknowledgement	Spoken Tutorial Project is funded by NMEICT, MHRD, Government of India.
	Thank you for joining.

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Madhurig, PoojaMoolya, Ranipv076, Snehalathak