Difference between revisions of "Python/C2/Using-the-plot-command-interactively/English-timed"
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| − | + | |'''Time''' | |
| − | + | |'''Narration''' | |
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| − | | | + | | 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 |
| I hope you have, IPython running on your computer. | | I hope you have, IPython running on your computer. | ||
|- | |- | ||
| − | | | + | | 00:10 |
| At the end of this tutorial, you will be able to, | | At the end of this tutorial, you will be able to, | ||
| Line 18: | Line 19: | ||
|- | |- | ||
| − | | | + | | 00:20 |
| Lets start'' ipython''. | | Lets start'' ipython''. | ||
|- | |- | ||
| − | | | + | | 00:22 |
| Open the terminal and type ''ipython -pylab'' and hit enter. | | Open the terminal and type ''ipython -pylab'' and hit enter. | ||
|- | |- | ||
| − | | | + | | 00:35 |
| ''Pylab'' is a python library which provides plotting functionality. | | ''Pylab'' is a python library which provides plotting functionality. | ||
|- | |- | ||
| − | | | + | | 00:39 |
| It provides many other important mathematical and scientific functions. | | 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'' | | 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.` | | 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. | |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 | | 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. | | as the documentation says, it returns ''num'' evenly spaced samples, calculated over the interval start and stop. | ||
|- | |- | ||
| − | | | + | | 01:29 |
| To illustrate this, lets try to generate ''100 points''. | | To illustrate this, lets try to generate ''100 points''. | ||
|- | |- | ||
| − | | | + | | 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 |
| 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 |
| Now lets try to generate'' 200 points between 0 and 1''. | | Now lets try to generate'' 200 points between 0 and 1''. | ||
|- | |- | ||
| − | | | + | |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 |
| 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 |
| 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 |
|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 |
| Here 'pi' is a constant defined by ''pylab''. | | Here 'pi' is a constant defined by ''pylab''. | ||
|- | |- | ||
| − | | | + | | 02:34 |
| Save this to the variable,say ''p''. | | Save this to the variable,say ''p''. | ||
|- | |- | ||
| − | | | + | | 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 |
| ''len'' function gives the no of elements of a sequence. | | ''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. | | 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. | | 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 | | 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. | | 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()''. | | As we do not wish to clutter the area with overlaid plots , we just clear it with ''clf()''. | ||
|- | |- | ||
| − | | | + | |04:34 |
|Now, lets try a sine plot. | |Now, lets try a sine plot. | ||
|- | |- | ||
| − | | | + | | 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. | ||
|- | |- | ||
| − | | | + | | 05:11 |
| Let us have a look at these options. | | 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 | | 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. | | To the bottom left of the window,there are a few buttons. | ||
|- | |- | ||
| − | | | + | | 05:30 |
|The right most among them is for saving the file. | |The right most among them is for saving the file. | ||
|- | |- | ||
| − | | | + | | 05:35 |
|Just click on it and type the file name. | |Just click on it and type the file name. | ||
|- | |- | ||
| − | | | + | | 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 |
| 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 ''dropdown''. | ||
|- | |- | ||
| − | | | + | | 06:05 |
|Formats like'' png ,eps ,pdf, ps'' are available. | |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. | | 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. | | Left to this is the zoom button by which we can zoom into the plot. | ||
|- | |- | ||
| − | | | + | | 06:30 |
| Just specify the region to ''zoom'' into. | | 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. | | 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. | | 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. | | 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. | | 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. | | Pause the video here, try out the following exercise and resume the video. | ||
|- | |- | ||
| − | | | + | | 07:20 |
|Plot ''(sin(x) into sin(x))'' by x. | |Plot ''(sin(x) into sin(x))'' by x. | ||
|- | |- | ||
| − | | | + | | 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 |
| Second one. ''Zoom'' and find the'' maxima''. | | Second one. ''Zoom'' and find the'' maxima''. | ||
|- | |- | ||
| − | | | + | | 07:37 |
| 3. Bring it back to initial position. | | 3. Bring it back to initial position. | ||
| − | |||
| − | |||
|- | |- | ||
| − | | | + | | 07:44 |
| Now, lets revise quickly what we have learnt today. | | Now, lets revise quickly what we have learnt today. | ||
|- | |- | ||
| − | | | + | | 07:49 |
|To Study ''Ipython'' with ''pylab''. | |To Study ''Ipython'' with ''pylab''. | ||
|- | |- | ||
| − | | | + | | 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 |
|To Find the length of sequences using ''len'' function. | |To Find the length of sequences using ''len'' function. | ||
|- | |- | ||
| − | | | + | | 08:01 |
| ''Plot'' mathematical functions using plot. | | ''Plot'' mathematical functions using plot. | ||
|- | |- | ||
| − | | | + | | 08:05 |
| To clear drawing area using ''clf''. | | 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''. | | 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?'' | | 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?'' | |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? | |The third one. How do you find the length of a sequence? | ||
|- | |- | ||
| − | | | + | | 08:43 |
| And the answers are, | | 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''. | |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. | |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. | |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. | | Hope you have enjoyed and found it useful. | ||
|- | |- | ||
| − | | | + | | 09:24 |
| Thank you! | | Thank you! | ||
Revision as of 12:14, 10 July 2014
| 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,
|
| 00:20 | Lets 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, lets 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 lets 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, lets 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 dropdown. |
| 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, lets 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! |
