Difference between revisions of "Python/C2/Embellishing-a-plot/English-timed"

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{| border=1
 
{| border=1
!Timing
+
|'''Time'''
!Narration
+
|'''Narration'''
 +
 
 
|-
 
|-
 
+
00:00
0:00
+
 
|Hello friends Welcome to the tutorial on "Embellishing a Plot".
 
|Hello friends Welcome to the tutorial on "Embellishing a Plot".
  
 
|-
 
|-
| 0:06
+
| 00:06
 
| At the end of this tutorial, you will be able to,
 
| At the end of this tutorial, you will be able to,
  
Line 16: Line 16:
 
# Add annotations to the plot.
 
# Add annotations to the plot.
 
# Set and Get the limits of axes.
 
# Set and Get the limits of axes.
 
 
  
 
|-
 
|-
| 0:27
+
| 00:27
 
| So, Before beginning this tutorial,we would suggest you to complete the tutorial on "Using plot interactively".
 
| So, Before beginning this tutorial,we would suggest you to complete the tutorial on "Using plot interactively".
  
 
|-
 
|-
| 0:34
+
| 00:34
 
| so,let us start ipython with pylab loaded, open the terminal and type ipython hyphen pylab.
 
| so,let us start ipython with pylab loaded, open the terminal and type ipython hyphen pylab.
  
 
|-
 
|-
| 0:48
+
| 00:48
 
| We shall first make a simple plot and start decorating it.
 
| We shall first make a simple plot and start decorating it.
  
 
|-
 
|-
| 0:54
+
| 00:54
 
|So type x is equal to linspace within brackets -2,4,20
 
|So type x is equal to linspace within brackets -2,4,20
  
 
|-
 
|-
| 1:06
+
| 01:06
 
|then type plot(x,sin(x))
 
|then type plot(x,sin(x))
  
 
|-
 
|-
| 1:15
+
| 01:15
 
| As we can see, the default colour and the default thickness of the line is as decided by pylab.
 
| As we can see, the default colour and the default thickness of the line is as decided by pylab.
  
 
|-
 
|-
| 1:23
+
| 01:23
 
| Wouldn't it be nice if we could control these parameters in the plot?  
 
| Wouldn't it be nice if we could control these parameters in the plot?  
  
 
|-
 
|-
| 1:28
+
| 01:28
 
|This is possible by passing additional arguments to the plot command.
 
|This is possible by passing additional arguments to the plot command.
  
 
|-
 
|-
| 1:33
+
| 01:33
 
| We shall first clear the figure and plot the same by passing the additional color argument.
 
| We shall first clear the figure and plot the same by passing the additional color argument.
  
 
|-
 
|-
| 1:39
+
| 01:39
 
| Pass the argument 'r' for red color.
 
| Pass the argument 'r' for red color.
  
 
|-
 
|-
| 1:44
+
| 01:44
 
| So type clf, then plot within brackets x,sin(x),within single quotes r.
 
| So type clf, then plot within brackets x,sin(x),within single quotes r.
  
 
|-
 
|-
2:13
+
02:13
 
| The same plot is seen in red color.
 
| The same plot is seen in red color.
  
 
|-
 
|-
| 2:16
+
| 02:16
 
| The thickness of the line can be altered by 'linewidth' argument.
 
| The thickness of the line can be altered by 'linewidth' argument.
  
 
|-
 
|-
| 2:20
+
| 02:20
 
|So type plot within brackets x,cos(x),linewidth is equal to 2
 
|So type plot within brackets x,cos(x),linewidth is equal to 2
  
 
|-
 
|-
| 2:34
+
| 02:34
 
|Now, a plot with line thickness 2 is produced.
 
|Now, a plot with line thickness 2 is produced.
  
 
|-
 
|-
| 2:40
+
| 02:40
 
| Pause the video here and do this exercise and then resume the video.
 
| Pause the video here and do this exercise and then resume the video.
  
 
|-
 
|-
| 2:45
+
| 02:45
 
|Plot sin(x) in blue color along with linewidth as 3.
 
|Plot sin(x) in blue color along with linewidth as 3.
  
 
|-
 
|-
| 2:53
+
| 02:53
 
| So, now switch to terminal for solution A combination of color and linewidth would do the job for us.
 
| So, now switch to terminal for solution A combination of color and linewidth would do the job for us.
  
 
|-
 
|-
| 3:01
+
| 03:01
 
|So , type clf , then type plot  x, sin(x),within single quotes b,linewidth is equal to 3.
 
|So , type clf , then type plot  x, sin(x),within single quotes b,linewidth is equal to 3.
  
 
|-
 
|-
| 3:16
+
| 03:16
 
| To get the style of line as bunch of points not joined, pass the linestyle argument with or without color argument.
 
| To get the style of line as bunch of points not joined, pass the linestyle argument with or without color argument.
  
 
|-
 
|-
| 3:25
+
| 03:25
 
| So for that type on the terminal clf, then type  plot x,sin(x), dot in single quotes.
 
| So for that type on the terminal clf, then type  plot x,sin(x), dot in single quotes.
  
 
|-
 
|-
| 3:43
+
| 03:43
 
| We get a plot with only points.
 
| We get a plot with only points.
  
 
|-
 
|-
| 3:49
+
| 03:49
 
| To get the same plot in blue color type clf, then type plot x, sin(x),within single quotes b dot.
 
| To get the same plot in blue color type clf, then type plot x, sin(x),within single quotes b dot.
  
 
|-
 
|-
| 4:02
+
| 04:02
 
| Other available options for passing arguments can be seen in the documentation of plot.
 
| Other available options for passing arguments can be seen in the documentation of plot.
  
 
|-
 
|-
| 4:07
+
| 04:07
 
|To see that we can type in the terminal plot then question mark.
 
|To see that we can type in the terminal plot then question mark.
  
 
|-
 
|-
| 4:19
+
| 04:19
 
| So, you can actually go through the documentation.
 
| So, you can actually go through the documentation.
 
  
 
|-
 
|-
| 4:23
+
| 04:23
 
| So ,pause the video here and do this exercise and then resume the video.
 
| So ,pause the video here and do this exercise and then resume the video.
  
 
|-
 
|-
| 4:28
+
| 04:28
 
|Plot the sine curve with green filled circles.
 
|Plot the sine curve with green filled circles.
  
 
|-
 
|-
| 4:33
+
| 04:33
 
| so ,for solutionNow, switch the terminal . We use a combination of linestyle and color.
 
| so ,for solutionNow, switch the terminal . We use a combination of linestyle and color.
  
 
|-
 
|-
|4:40
+
|04:40
 
|So ,type clf() then type plot within brackets x,cos(x), within single quotes go.
 
|So ,type clf() then type plot within brackets x,cos(x), within single quotes go.
  
 
|-
 
|-
|4:56
+
|04:56
 
|So, Pause the video here, try out the following exercise and resume the video.
 
|So, Pause the video here, try out the following exercise and resume the video.
  
 
|-
 
|-
|5:02
+
|05:02
 
|Plot the curve of x versus tan(x) in red dash line and linewidth 3.
 
|Plot the curve of x versus tan(x) in red dash line and linewidth 3.
  
 
|-
 
|-
| 5:13
+
| 05:13
 
| So for solution, we will switch to terminal .  
 
| So for solution, we will switch to terminal .  
  
 
|-
 
|-
| 5:18
+
| 05:18
 
|Here we shall use a combination of linewidth argument and linestyle.
 
|Here we shall use a combination of linewidth argument and linestyle.
  
 
|-
 
|-
|5:22
+
|05:22
 
|So in terminal you can type clf() then plot within brackets x, cos(x), within single quotes r hyphen hyphen
 
|So in terminal you can type clf() then plot within brackets x, cos(x), within single quotes r hyphen hyphen
  
 
|-
 
|-
| 5:36
+
| 05:36
 
| Now that we know how to produce a bare minimum plot with color, style and thickness of our interest, we shall look at further decorating the plot.
 
| Now that we know how to produce a bare minimum plot with color, style and thickness of our interest, we shall look at further decorating the plot.
  
 
|-
 
|-
5:46
+
05:46
 
| Let us start with a plot for the function minus x squared plus  4x minus  5.
 
| Let us start with a plot for the function minus x squared plus  4x minus  5.
  
 
|-
 
|-
|5:52
+
|05:52
 
|So for that you have to type clf then plot within brackets x,minus x star x plus 4 star x minus 5,'r',linewidth is equal to 2.
 
|So for that you have to type clf then plot within brackets x,minus x star x plus 4 star x minus 5,'r',linewidth is equal to 2.
  
 
|-
 
|-
| 6:16
+
| 06:16
 
| As you can see, the figure does not have any description describing the plot.
 
| As you can see, the figure does not have any description describing the plot.
  
 
|-
 
|-
| 6:21
+
| 06:21
 
|To add a title to the plot to describe what the plot is,use the title command.
 
|To add a title to the plot to describe what the plot is,use the title command.
  
 
|-
 
|-
|6:26
+
|06:26
 
|So, we can type in the terminal title within brackets and double quotes Parabolic function - x squared plus  4x minus 5
 
|So, we can type in the terminal title within brackets and double quotes Parabolic function - x squared plus  4x minus 5
  
 
|-
 
|-
|6:42
+
|06:42
 
|The figure now has a title.
 
|The figure now has a title.
  
 
|-
 
|-
|6:45
+
|06:45
 
| But it is not formatted and does not look clean.
 
| But it is not formatted and does not look clean.
  
 
|-
 
|-
| 6:49
+
| 06:49
 
| It would look shabby if there were fractions and more complex functions like log and exp.
 
| It would look shabby if there were fractions and more complex functions like log and exp.
  
 
|-
 
|-
| 6:57
+
| 06:57
 
| So, Wouldn't it be good if the title is seen in LaTeX like formatting?
 
| So, Wouldn't it be good if the title is seen in LaTeX like formatting?
  
 
|-
 
|-
| 7:03
+
| 07:03
 
| This is possible by adding a '$' sign before and after the part of the string that should be in LaTeX style.
 
| This is possible by adding a '$' sign before and after the part of the string that should be in LaTeX style.
  
 
|-
 
|-
|7:10
+
|07:10
 
| So in the command you can type title within brackets  Parabolic function dollar sign minus x squared plus 4x minus 5 dollar sign
 
| So in the command you can type title within brackets  Parabolic function dollar sign minus x squared plus 4x minus 5 dollar sign
 
  
 
|-
 
|-
| 7:26
+
| 07:26
 
| As we can see, the polynomial is now formatted.
 
| As we can see, the polynomial is now formatted.
  
 
|-
 
|-
| 7:30
+
| 07:30
 
|So, Pause the video here, try out the following exercise and resume the video.
 
|So, Pause the video here, try out the following exercise and resume the video.
  
 
|-
 
|-
| 7:35
+
| 07:35
 
| Change the title of the figure such that the whole title is formatted in LaTeX style.
 
| Change the title of the figure such that the whole title is formatted in LaTeX style.
  
 
|-
 
|-
| 7:41
+
| 07:41
 
|So for that Switch to terminal for solution.  
 
|So for that Switch to terminal for solution.  
  
 
|-
 
|-
| 7:45
+
| 07:45
 
| The solution is to enclose the whole string in between '$'.
 
| The solution is to enclose the whole string in between '$'.
  
 
|-
 
|-
|7:51
+
|07:51
 
|So you can type title within brackets dollar sign Parabolic function -x squared plus 4x minus 5 dollar sign.
 
|So you can type title within brackets dollar sign Parabolic function -x squared plus 4x minus 5 dollar sign.
  
 
|-
 
|-
| 8:01
+
| 08:01
 
| Although we have title, the plot is not complete without labelling x and y axes.  
 
| Although we have title, the plot is not complete without labelling x and y axes.  
  
 
|-
 
|-
| 8:05
+
| 08:05
 
| we shall label x-axis to "x" and y-axis to "f(x)".
 
| we shall label x-axis to "x" and y-axis to "f(x)".
  
 
|-
 
|-
| 8:12
+
| 08:12
 
|So for that you can type in terminal xlabel within brackets in double quotes x , then ylabel in  terminal within brackets in double quotes f of x.
 
|So for that you can type in terminal xlabel within brackets in double quotes x , then ylabel in  terminal within brackets in double quotes f of x.
  
 
|-
 
|-
| 8:31
+
| 08:31
 
| As you can see, xlabel and 'ylabel' command takes a string as an argument.  
 
| As you can see, xlabel and 'ylabel' command takes a string as an argument.  
  
 
|-
 
|-
| 8:37
+
| 08:37
 
| xlabel sets the label to x-axis as 'x' and ylabel sets the name to the y-axis as 'f(x)'.
 
| xlabel sets the label to x-axis as 'x' and ylabel sets the name to the y-axis as 'f(x)'.
 
  
 
|-
 
|-
| 8:50
+
| 08:50
 
|So now Pause the video here, try out the following exercise and resume the video.
 
|So now Pause the video here, try out the following exercise and resume the video.
  
 
|-
 
|-
| 8:57
+
| 08:57
 
| Set the x and y labels as "x" and "f(x)" in LaTeX style.
 
| Set the x and y labels as "x" and "f(x)" in LaTeX style.
  
 
|-
 
|-
| 9:04
+
| 09:04
 
| Since we need LaTeX style formatting, all we have to do is enclose the string in between two '$'.
 
| Since we need LaTeX style formatting, all we have to do is enclose the string in between two '$'.
  
 
|-
 
|-
| 9:10
+
| 09:10
 
| Switch to terminal and  type xlabel within brackets in double quote in between two dollar sign x and then type ylabel and again  brackets  double quotes  in between two dollar sign f of x .
 
| Switch to terminal and  type xlabel within brackets in double quote in between two dollar sign x and then type ylabel and again  brackets  double quotes  in between two dollar sign f of x .
 
   
 
   
 
 
|-
 
|-
| 9:31
+
| 09:31
 
| The plot is now almost complete except that the points are not named.
 
| The plot is now almost complete except that the points are not named.
  
 
|-
 
|-
| 9:37
+
| 09:37
 
| For example the point (2, -1) is the local maxima.
 
| For example the point (2, -1) is the local maxima.
  
 
|-
 
|-
| 9:42
+
| 09:42
 
| We would like to name the point accordingly.  
 
| We would like to name the point accordingly.  
  
 
|-
 
|-
|9:47
+
|09:47
 
|To do this use the function annotate.
 
|To do this use the function annotate.
  
 
|-
 
|-
|9:49
+
|09:49
 
|So for that you can type in the terminal annotate within brackets in double quotes local maxima comma xy is equal to within brackets 2 comma -1.
 
|So for that you can type in the terminal annotate within brackets in double quotes local maxima comma xy is equal to within brackets 2 comma -1.
  
Line 427: Line 421:
 
| 14:07
 
| 14:07
 
| And the final question. How do you set the title as x^2-5x+6 in LaTex style formatting.
 
| And the final question. How do you set the title as x^2-5x+6 in LaTex style formatting.
 
  
 
|-
 
|-

Revision as of 12:19, 10 July 2014

Time Narration
00:00 Hello friends Welcome to the tutorial on "Embellishing a Plot".
00:06 At the end of this tutorial, you will be able to,
  1. Modify the attributes of the plot -- color, line style,linewidth.
  2. Add a title to the plot with embedded LaTeX.
  3. Label x and y axes.
  4. Add annotations to the plot.
  5. Set and Get the limits of axes.
00:27 So, Before beginning this tutorial,we would suggest you to complete the tutorial on "Using plot interactively".
00:34 so,let us start ipython with pylab loaded, open the terminal and type ipython hyphen pylab.
00:48 We shall first make a simple plot and start decorating it.
00:54 So type x is equal to linspace within brackets -2,4,20
01:06 then type plot(x,sin(x))
01:15 As we can see, the default colour and the default thickness of the line is as decided by pylab.
01:23 Wouldn't it be nice if we could control these parameters in the plot?
01:28 This is possible by passing additional arguments to the plot command.
01:33 We shall first clear the figure and plot the same by passing the additional color argument.
01:39 Pass the argument 'r' for red color.
01:44 So type clf, then plot within brackets x,sin(x),within single quotes r.
02:13 The same plot is seen in red color.
02:16 The thickness of the line can be altered by 'linewidth' argument.
02:20 So type plot within brackets x,cos(x),linewidth is equal to 2
02:34 Now, a plot with line thickness 2 is produced.
02:40 Pause the video here and do this exercise and then resume the video.
02:45 Plot sin(x) in blue color along with linewidth as 3.
02:53 So, now switch to terminal for solution A combination of color and linewidth would do the job for us.
03:01 So , type clf , then type plot x, sin(x),within single quotes b,linewidth is equal to 3.
03:16 To get the style of line as bunch of points not joined, pass the linestyle argument with or without color argument.
03:25 So for that type on the terminal clf, then type plot x,sin(x), dot in single quotes.
03:43 We get a plot with only points.
03:49 To get the same plot in blue color type clf, then type plot x, sin(x),within single quotes b dot.
04:02 Other available options for passing arguments can be seen in the documentation of plot.
04:07 To see that we can type in the terminal plot then question mark.
04:19 So, you can actually go through the documentation.
04:23 So ,pause the video here and do this exercise and then resume the video.
04:28 Plot the sine curve with green filled circles.
04:33 so ,for solutionNow, switch the terminal . We use a combination of linestyle and color.
04:40 So ,type clf() then type plot within brackets x,cos(x), within single quotes go.
04:56 So, Pause the video here, try out the following exercise and resume the video.
05:02 Plot the curve of x versus tan(x) in red dash line and linewidth 3.
05:13 So for solution, we will switch to terminal .
05:18 Here we shall use a combination of linewidth argument and linestyle.
05:22 So in terminal you can type clf() then plot within brackets x, cos(x), within single quotes r hyphen hyphen
05:36 Now that we know how to produce a bare minimum plot with color, style and thickness of our interest, we shall look at further decorating the plot.
05:46 Let us start with a plot for the function minus x squared plus 4x minus 5.
05:52 So for that you have to type clf then plot within brackets x,minus x star x plus 4 star x minus 5,'r',linewidth is equal to 2.
06:16 As you can see, the figure does not have any description describing the plot.
06:21 To add a title to the plot to describe what the plot is,use the title command.
06:26 So, we can type in the terminal title within brackets and double quotes Parabolic function - x squared plus 4x minus 5
06:42 The figure now has a title.
06:45 But it is not formatted and does not look clean.
06:49 It would look shabby if there were fractions and more complex functions like log and exp.
06:57 So, Wouldn't it be good if the title is seen in LaTeX like formatting?
07:03 This is possible by adding a '$' sign before and after the part of the string that should be in LaTeX style.
07:10 So in the command you can type title within brackets Parabolic function dollar sign minus x squared plus 4x minus 5 dollar sign
07:26 As we can see, the polynomial is now formatted.
07:30 So, Pause the video here, try out the following exercise and resume the video.
07:35 Change the title of the figure such that the whole title is formatted in LaTeX style.
07:41 So for that Switch to terminal for solution.
07:45 The solution is to enclose the whole string in between '$'.
07:51 So you can type title within brackets dollar sign Parabolic function -x squared plus 4x minus 5 dollar sign.
08:01 Although we have title, the plot is not complete without labelling x and y axes.
08:05 we shall label x-axis to "x" and y-axis to "f(x)".
08:12 So for that you can type in terminal xlabel within brackets in double quotes x , then ylabel in terminal within brackets in double quotes f of x.
08:31 As you can see, xlabel and 'ylabel' command takes a string as an argument.
08:37 xlabel sets the label to x-axis as 'x' and ylabel sets the name to the y-axis as 'f(x)'.
08:50 So now Pause the video here, try out the following exercise and resume the video.
08:57 Set the x and y labels as "x" and "f(x)" in LaTeX style.
09:04 Since we need LaTeX style formatting, all we have to do is enclose the string in between two '$'.
09:10 Switch to terminal and type xlabel within brackets in double quote in between two dollar sign x and then type ylabel and again brackets double quotes in between two dollar sign f of x .
09:31 The plot is now almost complete except that the points are not named.
09:37 For example the point (2, -1) is the local maxima.
09:42 We would like to name the point accordingly.
09:47 To do this use the function annotate.
09:49 So for that you can type in the terminal annotate within brackets in double quotes local maxima comma xy is equal to within brackets 2 comma -1.
10:04 As you can see, the first argument to annotate command is the name we would like to mark the point as, and the second argument is the co-ordinates of the point at which the name should appear.
10:18 It is a tuple containing two numbers.
10:20 The first is x co-ordinate and second is y co-ordinate.
10:25 Pause the video, do this exercise and then resume the video.
10:30 Make an annotation called "root" at the point (-4, 0).
10:38 What happens to the first annotation ?
10:43 For that Switch to the terminal for the solution.
10:46 As we can see, every annotate command makes a new annotation on the figure.
10:52 Now we have everything we need to decorate a plot, but the plot would be incomplete if we can not set the limits of axes.
11:01 This can be done using the button provided on the plot window.
11:06 Else limits also can be get and set from the terminal.
11:13 Use "xlim()"function and "ylim()" function to get the limits.
11:17 So type in the terminal annotate within brackets in double quotes root comma xy is equal to within brackets minus 4 comma 0.
11:32 xlim function returns the current x axis limits and ylimfunction returns the current y-axis limits.
11:41 Set the limits of x-axis from -4 to 5 by giving command xlim(-4,5). So in the terminal you can type xlim() and then again ylim () then type xlim(-4,5).
12:12 Similarly set the limits of y-axis appropriately.So you can type ylim(-15,2)
12:22 Pause the video, do this exercise and then resume the video.
12:27 Set the limits of axes such that the area of interest is the rectangle (-1, -15) and (3, 0)
12:37 Switch to the terminal for the solution.


12:40 As we can see, the lower and upper limits of x-axis in the exercise are -1 and 3 respectively.
12:46 The lower and upper limits of y-axis are -15 and 0 respectively.
12:51 So in the command we can type xlim within brackets -1 comma 3 and ylim within brackets -15 comma 0.
13:02 This gives us the required rectangle.
13:09 This brings us to the end of this tutorial.In this tutorial,we have learnt to,Modify the attributes of plot like color, line width, line style by passing additional arguments.
13:20 Add title to a plot using 'title' command.
13:24 Incorporate LaTeX style formatting by adding a $ sign before and after the part of the string.
13:30 Label x and y axes using xlabel()function and ylabel() commands.
13:36 Then, add annotations to a plot using annotate() command.
13:38 Get and set the limits of axes using xlim() and ylim() commands.
13:46 Here are some self assessment questions for you to solve.
13:50 1. Draw a plot of cosine graph between -2pi to 2pi with line thickness 4.
13:57 2. Read through the documentation and find out, is there a way to modify the alignment of text in the command ylabel.
14:05 Yes or No are the options.
14:07 And the final question. How do you set the title as x^2-5x+6 in LaTex style formatting.
14:15 Now, the answers,
14:20 1. In order to plot a cosine graph between the points -2pi and 2pi with line thickness 4,we use the linspace and plot command as, x = linspace(-2*pi, 2*pi)
14:41 then plot(x, cos(x), linewidth=4)
14:46 And the second answer is No. We do not have an option to modify the alignment of text in the command ylabel.
14:53 Then the third and final one. To set the title in LaTex style formatting,we write the equation between two dollar signs as,
title("$x^2-5x+6$")
15:11 Hope you have enjoyed this tutorial and found it useful.


Contributors and Content Editors

Gaurav, Kavita salve, Minal, PoojaMoolya, Sandhya.np14, Sneha