Difference between revisions of "Python/C2/Using-the-plot-command-interactively/English-timed"

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(Created page with '{| border=1 !Timing !Visual Cue |- | 0:00 | Hello Friends and welcome to the tutorial on creating simple plots using iPython. |- | 0:06 | I hope you have IPython running on your…')
 
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| 0:00
 
| 0:00
| Hello Friends and welcome to the tutorial on creating simple plots using iPython.
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| Hello Friends and welcome to the tutorial on ''creating simple plots using iPython''.
  
 
|-
 
|-
 
| 0:06
 
| 0:06
| I hope you have IPython running on your computer.
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| I hope you have, IPython running on your computer.
  
 
|-
 
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|-
 
|-
 
|  0:20
 
|  0:20
| Lets start ipython.
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| Lets start'' ipython''.
  
 
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|-
 
| 0:22
 
| 0:22
| Open the terminal and type ipython -pylab and hit enter.
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| Open the terminal and type ''ipython -pylab'' and hit enter.
  
 
|-
 
|-
 
| 0:35
 
| 0:35
| <nowiki>Pylab is a python library which provides plotting functionality</nowiki>.
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| ''Pylab'' is a python library which provides plotting functionality.
  
 
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| 0:43
 
| 0:43
| <nowiki>After running IPython -pylab in the shell you will see some information about ipython and pylab followed by the In[1] prompt</nowiki>.
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| After running, IPython -pylab in the shell you will see some information about ipython and pylab followed by the ''In[1] prompt''
  
 
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|-
 
| 0:55
 
| 0:55
| But if you get an error like `ERROR: matplotlib could NOT be imported!  Starting normal IPython.`
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| But if you get an error like `ERROR: ''matplotlib'' could NOT be imported!  Starting normal IPython.`
  
 
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|-
 
| 1:02
 
| 1:02
|Then you will have to install the matplotlib and run this command again.
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|Then you will have to install the ''matplotlib ''and run this command again.
  
 
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| 1:29
 
| 1:29
| To illustrate this, lets try to generate 100 points.
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| To illustrate this, lets try to generate ''100 points''.
  
 
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|-
 
| 1:33
 
| 1:33
| Type <tt>linspace within brackets 1 comma 100 comma 100 </tt> and hit enter.
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| Type <tt>linspace within brackets ''1 comma 100 comma 100'' </tt> and hit enter.
  
 
|-
 
|-
 
| 1:47
 
| 1:47
| As you can see a sequence of numbers from 1 to 100 appears.
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| As you can see a sequence of numbers from ''1 to 100 appears.
  
 
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| 1:52
 
| 1:52
| Now lets try to generate 200 points between 0 and 1.
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| Now lets try to generate'' 200 points between 0 and 1''.
  
 
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|1:57
 
|1:57
|we do that by typing linspace within brackets 0 comma 1 comma 200.
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|we do that by typing'' linspace'' within brackets ''0 comma 1 comma 200''.
  
 
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|-
 
| 2:11
 
| 2:11
| Here,0 is the start , 1 the stop and 200 the number of points.
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| Here,''0'' is the start , 1 the stop and 200 the number of points.
  
 
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| In linspace the start and stop points can be integers, decimals , or constants.  
 
| In linspace the start and stop points can be integers, decimals , or constants.  
  
|-
+
|-  
 
| 2:24
 
| 2:24
|Let's try and get 100 points between  minus pi to pi.
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|Let's try and get ''100 points between  minus pi to pi''.
  
 
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| 2:30
 
| 2:30
| Here 'pi' is a constant defined by pylab.
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| Here 'pi' is a constant defined by ''pylab''.
  
 
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| 2:34
 
| 2:34
| Save this to the variable,say p.
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| Save this to the variable,say ''p''.
  
 
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| 2:52
 
| 2:52
| If we now type <tt>len within brackets p</tt> we will get the no. of points.
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| If we now type ''len'' within brackets ''p'' we will get the no. of points.
  
 
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| 3:05
| <tt>len</tt> function gives the no of elements of a sequence.
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| ''len'' function gives the no of elements of a sequence.
  
 
|-
 
|-
 
| 3:11
 
| 3:11
| Let's try and plot a cosine curve between minus pi and pi. For this we use the plot command. Here cos(p) gets the cosine value at every point corresponding to point p.
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| Let's try and plot a cosine curve between minus pi and pi. For this we use the plot command. Here ''cos(p)'' gets the cosine value at every point corresponding to point p.
  
 
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| 3:50
 
| 3:50
| We can save cos(p) to variable cosine and then plot it using the plot function.
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| We can save ''cos(p)'' to variable cosine and then plot it using the plot function.
  
 
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| 3:57
 
| 3:57
| Now to clear the plot ,we use the <tt>clf closing brackets</tt> function
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| Now to clear the plot ,we use the ''clf'' closing brackets function
  
 
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| 4:19  
 
| 4:19  
| This is done because if we wish to make another plot, it will overlap the previous plot.
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| This is done, because if we wish to make another plot, it will overlap the previous plot.
  
 
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| 4:25
 
| 4:25
| As we do not wish to clutter the area with overlaid plots , we just clear it with clf().  
+
| As we do not wish to clutter the area with overlaid plots , we just clear it with ''clf()''.  
  
 
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|-
 
|4:34
 
|4:34
|Now lets try a sine plot.
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|Now, lets try a sine plot.
  
 
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| 5:48
|We will save the plot by the name ''sin_curve'' in pdf format.
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|We will save the file  by the name ''sin_curve'' in pdf format.
  
 
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| 6:00
 
| 6:00
| As you can see we can specify the format of file from the dropdown.  
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| As you can see we can specify the format of file from the ''dropdown''.  
  
 
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| 6:05
 
| 6:05
|Formats like png ,eps ,pdf, ps are available.
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|Formats like'' png ,eps ,pdf, ps'' are available.
  
 
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| Just specify the region to zoom into.
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| Just specify the region to ''zoom'' into.
  
 
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| The next two buttons with left and right arrow icons change the state of the plot and take it to the previous state it was in.
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| The next two buttons with'' left and right'' arrow icons change the state of the plot and take it to the previous state it was in.
  
 
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| 7:00
 
| 7:00
| It more or less acts like the back and forward button in a browser.
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| It more or less acts like the ''back and forward ''button in a browser.
  
 
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|Plot (sin(x) into sin(x)) by x.
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|Plot ''(sin(x) into sin(x))'' by x.
  
 
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| 7:26
 
| 7:26
| 1. Save the plot by the sin square by x.pdf in pdf format.
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| 1. Save the plot by the sin square by ''x.pdf ''in pdf format.
  
 
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| 7:33
 
| 7:33
| Second one. Zoom and find the maxima.
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| Second one. ''Zoom'' and find the'' maxima''.
  
 
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| 7:49
 
| 7:49
|To Study Ipython with pylab.
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|To Study ''Ipython'' with ''pylab''.
  
 
|-
 
|-
 
| 7:52
 
| 7:52
| To Use the linspace function to create ''num'' equally spaced points in a region.
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| To Use the ''linspace ''function to create ''num'' equally spaced points in a region.
  
 
|-
 
|-
 
| 7:57
 
| 7:57
|To Find the length of sequences using len function.
+
|To Find the length of sequences using ''len'' function.
  
 
|-
 
|-
 
| 8:01
 
| 8:01
| Plot mathematical functions using plot.
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| ''Plot'' mathematical functions using plot.
  
 
|-
 
|-
 
| 8:05
 
| 8:05
| To clear drawing area using clf.
+
| To clear drawing area using ''clf''.
  
 
|-
 
|-
 
| 8:08
 
| 8:08
| To Use the UI of plot for studying it better and using functionality like save,zoom and moving the plots on x and y axis.
+
| To Use the'' UI'' of plot for studying it better and using functionality like save,zoom and moving the plots on ''x and y axis''.
  
 
|-
 
|-
 
| 8:23
 
| 8:23
| Create 100 equally spaced points between minus pi by 2 and pi by 2?
+
| Create 100 equally spaced points between minus pi by'' 2 and pi by 2?''
  
 
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| 8:31
 
| 8:31
|Second one is. How do you clear a figure in ipython?
+
|Second one is. How do you clear a figure in'' ipython?''
  
  
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|1.We use the command ''linspace within brackets minus pi by 2 comma pi by 2 comma 100'' to create 100 equally spaced lines between the points minus pi by 2 and pi by 2.
+
|1.We use the command ''linspace within brackets minus pi by ''2 comma pi by 2 comma 100'' to create 100 equally spaced lines between the points minus pi by 2 and pi by 2''.
  
 
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| 9:03
 
| 9:03
|Second one. We use clf closing bracket function to clear a figure.
+
|Second one. We use'' clf ''closing bracket function to clear a figure.
  
 
|-
 
|-

Revision as of 12:42, 4 March 2013

Timing Visual Cue
0:00 Hello Friends and welcome to the tutorial on creating simple plots using iPython.
0:06 I hope you have, IPython running on your computer.
0:10 At the end of this tutorial, you will be able to,
  1. Create simple plots of mathematical functions.
  2. Use the Figure window to study plots better.
0:20 Lets start ipython.
0:22 Open the terminal and type ipython -pylab and hit enter.
0:35 Pylab is a python library which provides plotting functionality.
0:39 It provides many other important mathematical and scientific functions.
0:43 After running, IPython -pylab in the shell you will see some information about ipython and pylab followed by the In[1] prompt
0:55 But if you get an error like `ERROR: matplotlib could NOT be imported! Starting normal IPython.`
1:02 Then you will have to install the matplotlib and run this command again.
1:08 Now type 'linspace' followed by a '?' mark in your ipython shell
1:19 as the documentation says, it returns num evenly spaced samples, calculated over the interval start and stop.
1:29 To illustrate this, lets try to generate 100 points.
1:33 Type linspace within brackets 1 comma 100 comma 100 and hit enter.
1:47 As you can see a sequence of numbers from 1 to 100 appears.
1:52 Now lets try to generate 200 points between 0 and 1.
1:57 we do that by typing linspace within brackets 0 comma 1 comma 200.
2:11 Here,0 is the start , 1 the stop and 200 the number of points.
2:18 In linspace the start and stop points can be integers, decimals , or constants.
2:24 Let's try and get 100 points between minus pi to pi.
2:30 Here 'pi' is a constant defined by pylab.
2:34 Save this to the variable,say p.
2:52 If we now type len within brackets p we will get the no. of points.
3:05 len function gives the no of elements of a sequence.
3:11 Let's try and plot a cosine curve between minus pi and pi. For this we use the plot command. Here cos(p) gets the cosine value at every point corresponding to point p.
3:50 We can save cos(p) to variable cosine and then plot it using the plot function.
3:57 Now to clear the plot ,we use the clf closing brackets function
4:19 This is done, because if we wish to make another plot, it will overlap the previous plot.
4:25 As we do not wish to clutter the area with overlaid plots , we just clear it with clf().
4:34 Now, lets try a sine plot.
5:04 We can study the plot better on the plot window by using the various options available on it.
5:11 Let us have a look at these options.
5:14 As we can observe, moving the mouse pointer along the plot gives us the location of each point on the plot
5:26 To the bottom left of the window,there are a few buttons.
5:30 The right most among them is for saving the file.
5:35 Just click on it and type the file name.
5:48 We will save the file by the name sin_curve in pdf format.
6:00 As you can see we can specify the format of file from the dropdown.
6:05 Formats like png ,eps ,pdf, ps are available.
6:17 Left to the save button is the slider button by which we can specify the margins.
6:25 Left to this is the zoom button by which we can zoom into the plot.
6:30 Just specify the region to zoom into.
6:40 The button to the left of it can be used to move the axes of the plot.
6:50 The next two buttons with left and right arrow icons change the state of the plot and take it to the previous state it was in.
7:00 It more or less acts like the back and forward button in a browser.
7:06 The last one is 'home' referring to the initial plot.
7:13 Pause the video here, try out the following exercise and resume the video.
7:20 Plot (sin(x) into sin(x)) by x.
7:26 1. Save the plot by the sin square by x.pdf in pdf format.
7:33 Second one. Zoom and find the maxima.
7:37 3. Bring it back to initial position.


7:44 Now, lets revise quickly what we have learnt today.
7:49 To Study Ipython with pylab.
7:52 To Use the linspace function to create num equally spaced points in a region.
7:57 To Find the length of sequences using len function.
8:01 Plot mathematical functions using plot.
8:05 To clear drawing area using clf.
8:08 To Use the UI of plot for studying it better and using functionality like save,zoom and moving the plots on x and y axis.
8:23 Create 100 equally spaced points between minus pi by 2 and pi by 2?
8:31 Second one is. How do you clear a figure in ipython?


8:36 The third one. How do you find the length of a sequence?
8:43 And the answers are,
8:45 1.We use the command linspace within brackets minus pi by 2 comma pi by 2 comma 100 to create 100 equally spaced lines between the points minus pi by 2 and pi by 2.
9:03 Second one. We use clf closing bracket function to clear a figure.
9:11 Third one. len within brackets sequence_name is the function used to find out the length of a sequence.


9:20 Hope you have enjoyed and found it useful.
9:24 Thank you!

Contributors and Content Editors

Gaurav, Minal, PoojaMoolya, Sandhya.np14, Sneha