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

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|-
 
|-
 
| 00:00
 
| 00:00
| Hello Friends and welcome to the tutorial on ''creating simple plots using iPython''.
+
| Hello friends and welcome to the tutorial on ''creating simple plots using iPython''.
  
 
|-
 
|-
 
| 00:06
 
| 00:06
| I hope you have, IPython running on your computer.
+
| I hope you have '''iPython''' running on your computer.
  
 
|-
 
|-
 
| 00:10
 
| 00:10
| At the end of this tutorial, you will be able to,
+
| At the end of this tutorial, you will be able to:
 
+
Create simple plots of mathematical functions.
# Create simple plots of mathematical functions.
+
Use the Figure window to study plots better.
# Use the Figure window to study plots better.
+
  
 
|-
 
|-
 
|  00:20
 
|  00:20
| Lets start'' ipython''.
+
| Let's start''' ipython'''.
  
 
|-
 
|-
 
| 00:22
 
| 00:22
| Open the terminal and type ''ipython -pylab'' and hit enter.
+
| Open the terminal and type: ''ipython -pylab'' and hit '''Enter'''.
  
 
|-
 
|-
 
| 00:35
 
| 00:35
| ''Pylab'' is a python library which provides plotting functionality.
+
| '''Pylab''' is a '''python library''' which provides plotting functionality.
  
 
|-
 
|-
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|-
 
|-
 
| 00:43
 
| 00:43
| After running, IPython -pylab in the shell you will see some information about ipython and pylab followed by the ''In[1] prompt''
+
| After running '''IPython -pylab''' in the '''shell''', you will see some information about 'ipython' and '''pylab''' followed by the '''In[1] prompt'''.
  
 
|-
 
|-
 
| 00:55
 
| 00:55
| But if you get an error like `ERROR: ''matplotlib'' could NOT be imported!  Starting normal IPython.`
+
| But, if you get an error like 'ERROR: ''matplotlib'' could NOT be imported!  Starting normal IPython.'
  
 
|-
 
|-
 
| 01:02
 
| 01:02
|Then you will have to install the ''matplotlib ''and run this command again.
+
|then you will have to install the ''matplotlib ''and run this command again.
  
 
|-
 
|-
 
| 01:08
 
| 01:08
| Now type 'linspace' followed by a '?' mark in your ipython shell
+
| Now type: 'linspace' followed by a '?' mark in your '''ipython shell'''.
  
 
|-
 
|-
 
|  01:19
 
|  01:19
| as the documentation says, it returns ''num'' evenly spaced samples, calculated over the interval start and stop.
+
| As the documentation says, it "returns 'num' evenly spaced samples, calculated over the interval 'start' and 'stop'".
  
 
|-
 
|-
 
| 01:29
 
| 01:29
| To illustrate this, lets try to generate ''100 points''.
+
| To illustrate this, let's try to generate ''100 points''.
  
 
|-
 
|-
 
| 01:33
 
| 01:33
| Type <tt>linspace within brackets ''1 comma 100 comma 100'' </tt> and hit enter.
+
| Type: <tt>linspace within brackets '''1 comma 100 comma 100''' </tt> and hit '''Enter'''.
  
 
|-
 
|-
 
| 01:47
 
| 01:47
| As you can see a sequence of numbers from ''1 to 100 appears.
+
| As you can see, a sequence of numbers from 1 to 100 appears.
  
 
|-
 
|-
 
| 01:52
 
| 01:52
| Now lets try to generate'' 200 points between 0 and 1''.
+
| Now let's try to generate 200 points between 0 and 1.
  
 
|-
 
|-
 
|01:57
 
|01:57
|we do that by typing'' linspace'' within brackets ''0 comma 1 comma 200''.
+
|we do that by typing''' linspace''' within brackets '''0 comma 1 comma 200'''.
  
 
|-
 
|-
 
| 02:11
 
| 02:11
| Here,''0'' is the start , 1 the stop and 200 the number of points.
+
| Here, 0 is the start, 1- the stop and 200- the number of points.
  
 
|-
 
|-
 
| 02:18
 
| 02:18
| 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.  
  
 
|-  
 
|-  
 
| 02:24
 
| 02:24
|Let's try and get ''100 points between  minus pi to pi''.
+
|Let's try and get 100 points between  minus 'pi' to 'pi'.
  
 
|-
 
|-
 
| 02:30
 
| 02:30
| Here 'pi' is a constant defined by ''pylab''.
+
| Here 'pi' is a constant defined by '''pylab'''.
  
 
|-
 
|-
 
| 02:34
 
| 02:34
| Save this to the variable,say ''p''.
+
| Save this to the variable, say 'p'.
  
 
|-
 
|-
 
| 02:52
 
| 02:52
| If we now type ''len'' within brackets ''p'' we will get the no. of points.
+
| If we now type 'len' within brackets 'p', we will get the no. of points.
  
 
|-
 
|-
 
| 03:05
 
| 03:05
| ''len'' function gives the no of elements of a sequence.
+
| '''len''' function gives the no. of '''element'''s of a sequence.
  
 
|-
 
|-
 
| 03:11
 
| 03:11
| 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.
+
| 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'.
  
 
|-
 
|-
 
| 03:50
 
| 03:50
| We can save ''cos(p)'' to variable cosine and then plot it using the plot function.
+
| We can save '''cos(p)''' to variable 'cosine' and then plot it using the '''plot''' function.
  
 
|-
 
|-
 
| 03:57
 
| 03:57
| Now to clear the plot ,we use the ''clf'' closing brackets function
+
| Now, to clear the plot, we use the '''clf''' closing brackets function.
  
 
|-
 
|-
 
| 04:19  
 
| 04:19  
| This is done, because if we wish to make another plot, it will overlap the previous plot.
+
| This is done because, if we wish to make another plot, it will overlap the previous plot.
  
 
|-
 
|-
 
| 04:25
 
| 04:25
| 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()'''.  
  
 
|-
 
|-
 
|04:34
 
|04:34
|Now, lets try a sine plot.
+
|Now, let's try a 'sine plot'.
  
 
|-
 
|-
 
| 05:04
 
| 05:04
| We can study the plot better on the plot window by using the various options available on it.
+
| We can study the plot better on the '''plot window''' by using the various options available on it.
  
 
|-
 
|-
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|-
 
|-
 
| 05:14
 
| 05:14
| As we can observe, moving the mouse pointer along the plot gives us the location of each point on the plot
+
| As we can observe, moving the '''mouse pointer''' along the plot gives us the location of each point on the plot.
  
 
|-
 
|-
 
| 05:26
 
| 05:26
| To the bottom left of the window,there are a few buttons.  
+
| To the bottom left of the window, there are a few buttons.  
  
 
|-
 
|-
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|-
 
|-
 
| 05:48
 
| 05:48
|We will save the file  by the name ''sin_curve'' in pdf format.
+
|We will '''save''' the file  by the name 'sin_curve' in ''''pdf' format'''.
  
 
|-
 
|-
 
| 06:00
 
| 06:00
| As you can see we can specify the format of file from the ''dropdown''.  
+
| As you can see, we can specify the format of file from the '''drop-down'''.  
  
 
|-
 
|-
 
| 06:05
 
| 06:05
|Formats like'' png ,eps ,pdf, ps'' are available.
+
|Formats like''' png, eps, pdf, ps''' are available.
  
 
|-
 
|-
 
| 06:17
 
| 06:17
| Left to the save button is the slider button by which we can specify the margins.
+
| Left to the '''save''' button is the '''slider''' button by which we can specify the margins.
  
 
|-
 
|-
 
| 06:25
 
| 06:25
| Left to this is the zoom button by which we can zoom into the plot.
+
| Left to this is the '''zoom''' button by which we can zoom into the plot.
  
 
|-
 
|-
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|-
 
|-
 
| 07:06
 
| 07:06
| The last one is 'home' referring to the initial plot.
+
| The last one is '''home''', referring to the initial plot.
  
 
|-
 
|-
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|-
 
|-
 
| 07:20
 
| 07:20
|Plot ''(sin(x) into sin(x))'' by x.
+
|Plot '''(sin(x) into sin(x))''' by x.
  
 
|-
 
|-
 
| 07:26
 
| 07:26
| 1. Save the plot by the sin square by ''x.pdf ''in pdf format.
+
| 1. '''Save''' the plot by the sin square by ''x.pdf ''in pdf format.
  
 
|-
 
|-
 
| 07:33
 
| 07:33
| Second one. ''Zoom'' and find the'' maxima''.
+
| Second one. ''Zoom'' and find the '''maxima'''.
  
 
|-
 
|-
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|-
 
|-
 
| 07:44
 
| 07:44
| Now, lets revise quickly what we have learnt today.
+
| Now, let's revise quickly what we have learnt today-
  
 
|-
 
|-
 
| 07:49
 
| 07:49
|To Study ''Ipython'' with ''pylab''.
+
|To Study '''Ipython''' with '''pylab'''.
  
 
|-
 
|-
 
| 07:52
 
| 07:52
| To Use the ''linspace ''function to create ''num'' equally spaced points in a region.
+
|To Use the '''linspace '''function to create '''num''' equally spaced points in a region.
  
 
|-
 
|-
 
| 07:57
 
| 07:57
|To Find the length of sequences using ''len'' function.
+
|To Find the length of sequences using '''len''' function.
  
 
|-
 
|-
 
| 08:01
 
| 08:01
| ''Plot'' mathematical functions using plot.
+
|Plot mathematical functions using '''plot'''.
  
 
|-
 
|-
 
| 08:05
 
| 08:05
| To clear drawing area using ''clf''.
+
|To clear drawing area using '''clf'''.
  
 
|-
 
|-
 
| 08:08
 
| 08:08
| 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''.
  
 
|-
 
|-
 
| 08:23
 
| 08:23
| 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?
  
 
|-
 
|-
 
| 08:31
 
| 08:31
|Second one is. How do you clear a figure in'' ipython?''
+
|Second one is- How do you clear a figure in''' ipython'''?
  
 
|-
 
|-
 
| 08:36
 
| 08:36
|The third one. How do you find the length of a sequence?
+
|The third one- How do you find the length of a sequence?
  
 
|-
 
|-
 
| 08:43
 
| 08:43
| And the answers are,
+
| And the answers are-
  
 
|-
 
|-
 
| 08:45
 
| 08:45
|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''.
+
|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''.
  
 
|-
 
|-
 
| 09:03
 
| 09:03
|Second one. We use'' clf ''closing bracket function to clear a figure.
+
|Second one- We use''' clf '''closing bracket function to clear a figure.
  
 
|-
 
|-
 
| 09:11
 
| 09:11
|Third one. ''len within brackets sequence_name'' is the function used to find out the length of a sequence.
+
|Third one- '''len''' within brackets 'sequence_name' is the function used to find out the length of a sequence.
  
 
|-
 
|-

Latest revision as of 18:01, 20 February 2017

Time Narration
00:00 Hello friends and welcome to the tutorial on creating simple plots using iPython.
00:06 I hope you have iPython running on your computer.
00:10 At the end of this tutorial, you will be able to:

Create simple plots of mathematical functions. Use the Figure window to study plots better.

00:20 Let's start ipython.
00:22 Open the terminal and type: ipython -pylab and hit Enter.
00:35 Pylab is a python library which provides plotting functionality.
00:39 It provides many other important mathematical and scientific functions.
00:43 After running IPython -pylab in the shell, you will see some information about 'ipython' and pylab followed by the In[1] prompt.
00:55 But, if you get an error like 'ERROR: matplotlib could NOT be imported! Starting normal IPython.'
01:02 then you will have to install the matplotlib and run this command again.
01:08 Now type: 'linspace' followed by a '?' mark in your ipython shell.
01:19 As the documentation says, it "returns 'num' evenly spaced samples, calculated over the interval 'start' and 'stop'".
01:29 To illustrate this, let's try to generate 100 points.
01:33 Type: linspace within brackets 1 comma 100 comma 100 and hit Enter.
01:47 As you can see, a sequence of numbers from 1 to 100 appears.
01:52 Now let's try to generate 200 points between 0 and 1.
01:57 we do that by typing linspace within brackets 0 comma 1 comma 200.
02:11 Here, 0 is the start, 1- the stop and 200- the number of points.
02:18 In linspace, the start and stop points can be integers, decimals or constants.
02:24 Let's try and get 100 points between minus 'pi' to 'pi'.
02:30 Here 'pi' is a constant defined by pylab.
02:34 Save this to the variable, say 'p'.
02:52 If we now type 'len' within brackets 'p', we will get the no. of points.
03:05 len function gives the no. of elements of a sequence.
03:11 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'.
03:50 We can save cos(p) to variable 'cosine' and then plot it using the plot function.
03:57 Now, to clear the plot, we use the clf closing brackets function.
04:19 This is done because, if we wish to make another plot, it will overlap the previous plot.
04:25 As we do not wish to clutter the area with overlaid plots, we just clear it with clf().
04:34 Now, let's try a 'sine plot'.
05:04 We can study the plot better on the plot window by using the various options available on it.
05:11 Let us have a look at these options.
05:14 As we can observe, moving the mouse pointer along the plot gives us the location of each point on the plot.
05:26 To the bottom left of the window, there are a few buttons.
05:30 The right most among them is for saving the file.
05:35 Just click on it and type the file name.
05:48 We will save the file by the name 'sin_curve' in 'pdf' format.
06:00 As you can see, we can specify the format of file from the drop-down.
06:05 Formats like png, eps, pdf, ps are available.
06:17 Left to the save button is the slider button by which we can specify the margins.
06:25 Left to this is the zoom button by which we can zoom into the plot.
06:30 Just specify the region to zoom into.
06:40 The button to the left of it can be used to move the axes of the plot.
06:50 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.
07:00 It more or less acts like the back and forward button in a browser.
07:06 The last one is home, referring to the initial plot.
07:13 Pause the video here, try out the following exercise and resume the video.
07:20 Plot (sin(x) into sin(x)) by x.
07:26 1. Save the plot by the sin square by x.pdf in pdf format.
07:33 Second one. Zoom and find the maxima.
07:37 3. Bring it back to initial position.
07:44 Now, let's revise quickly what we have learnt today-
07:49 To Study Ipython with pylab.
07:52 To Use the linspace function to create num equally spaced points in a region.
07:57 To Find the length of sequences using len function.
08:01 Plot mathematical functions using plot.
08:05 To clear drawing area using clf.
08:08 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.
08:23 Create 100 equally spaced points between minus pi by 2 and pi by 2?
08:31 Second one is- How do you clear a figure in ipython?
08:36 The third one- How do you find the length of a sequence?
08:43 And the answers are-
08:45 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.
09:03 Second one- We use clf closing bracket function to clear a figure.
09:11 Third one- len within brackets 'sequence_name' is the function used to find out the length of a sequence.
09:20 Hope you have enjoyed and found it useful.
09:24 Thank you!

Contributors and Content Editors

Gaurav, Minal, PoojaMoolya, Sandhya.np14, Sneha