9 Ipython is An Enhanced Interactive Python interpreter. It provides additional features like tab completion,easier access to help , and many other useful features which are not present in the vanilla Python interpreter. |
9 Ipython is An Enhanced Interactive Python interpreter. It provides additional features like tab completion,easier access to help , and many other useful features which are not present in the vanilla Python interpreter. |
10 Pylab is python library which provides plotting functionality. |
10 Pylab is python library which provides plotting functionality. |
11 |
11 |
12 I am assuming that both Ipython and Pylab are installed on your system . |
12 I am assuming that both Ipython and Pylab are installed on your system . |
13 |
13 |
14 *On your terminal type in the command Ipython -pylab |
14 *On your terminal type in the command |
15 $ ipython -pylab |
15 $ ipython -pylab |
16 press RETURN |
16 press RETURN |
17 |
17 |
18 We will first start with the customary Hello world program. print hello world |
18 We will first start with the customary Hello world program by writing: |
19 |
19 |
20 In []: print 'hello world' |
20 In []: print 'hello world' |
21 |
21 |
22 Voila we have got hello world as the output |
22 Voila we have got hello world as the output |
23 |
23 |
36 |
36 |
37 In [] x=linspace( RETURN |
37 In [] x=linspace( RETURN |
38 oops I made a mistake . As you can see I made the mistake of not writing command correctly |
38 oops I made a mistake . As you can see I made the mistake of not writing command correctly |
39 and Ipython changed the prompt . To get the old prompt back type crtl-c |
39 and Ipython changed the prompt . To get the old prompt back type crtl-c |
40 |
40 |
41 In []: x = linspace(0, 2*pi, 50) |
41 In []: x = linspace(0, 2*pi, 100) |
42 |
42 |
43 *As you can see linspace can take three parameters start, stop, and num and returns num evenly space points . You can scroll through the help to know more about the function |
43 *As you can see linspace can take three parameters start, stop, and num and returns num evenly space points . You can scroll through the help to know more about the function |
44 |
44 |
45 |
45 |
46 *To know more about any function, example for the 'linspace' function you can type ? after it . |
46 *To know more about any function, example for the 'linspace' function you can type ? after it . |
76 |
76 |
77 Ok what if I want the legend to be in different location. It just requires us to define one extra parameter. |
77 Ok what if I want the legend to be in different location. It just requires us to define one extra parameter. |
78 |
78 |
79 We have just typed legend command can we reuse it . Yes |
79 We have just typed legend command can we reuse it . Yes |
80 |
80 |
81 To go to previous command, we can use 'UP Arrow key' and 'DOWN' will take us (in reverse order)/back. |
81 To go to previous command, we can use 'UP Arrow key' and 'DOWN' will take us back. |
82 |
82 |
83 We can modify previous command to specify the location of the legend, by passing an additional argument to the function. |
83 We can modify previous command to specify the location of the legend, by passing an additional argument to the function. |
84 #Ask madhu how to describe the feature here. |
84 #Ask madhu how to describe the feature here. |
85 Once you start editing a previous command and then you try to use 'Up arrow key ' you can get commands that are only similar to the command you are editing. But if you move your cursor to the beginning of the line you can get all the previous commands using up and down arrow keys. |
85 Once you start editing a previous command and then you try to use 'Up arrow key ' you can get commands that are only similar to the command you are editing. But if you move your cursor to the beginning of the line you can get all the previous commands using up and down arrow keys. |
86 In []: legend(['sin(x)'], loc = 'center') |
86 In []: legend(['sin(x)'], loc = 'center') |
100 |
100 |
101 We save the plot by the function savefig |
101 We save the plot by the function savefig |
102 In []: savefig('sin.png') saves the figure with the name 'sin.png' in the current directory. |
102 In []: savefig('sin.png') saves the figure with the name 'sin.png' in the current directory. |
103 |
103 |
104 #other supported formats are: eps, ps, pdf etc. |
104 #other supported formats are: eps, ps, pdf etc. |
105 When we use plot again by default plots get overlaid. |
105 When we use plot again |
106 In []: plot(x, cos(x)) |
106 In []: plot(x, cos(x)) by default plots get overlaid. |
107 |
107 |
108 we update Y axis label |
108 we update Y axis label |
109 In []: ylabel('f(x)') |
109 In []: ylabel('f(x)') |
110 |
110 |
111 Now in these situations with overlaid graphs, legend becomes absolutely essential. To add multiple legends, we pass the strings within quotes separated by commas and enclosed within square brackets as shown. |
111 Now in these situations with overlaid graphs, legend becomes absolutely essential. To add multiple legends, we pass the strings within quotes separated by commas and enclosed within square brackets as shown. |
145 In []: close() |
145 In []: close() |
146 |
146 |
147 close() now closes the figure(2). |
147 close() now closes the figure(2). |
148 In []: close() |
148 In []: close() |
149 |
149 |
150 The plot command can take the parameters such as 'g' which generates the plot in green color. |
150 The plot command can take the additional parameters such as 'g' which generates the plot in green color. |
151 |
151 |
152 Passing the linewidth=2 option to plot, generates the plot with linewidth of two units. |
152 Passing the linewidth=2 option to plot, generates the plot with linewidth of two units. |
153 Use Up arrow to get to the previous commands |
153 Use Up arrow to get to the previous commands |
154 In []: plot(x, sin(x), 'g', linewidth=2) and add arguments |
154 In []: plot(x, sin(x), 'g', linewidth=2) and add arguments |
155 |
155 |
167 In []: clf() |
167 In []: clf() |
168 |
168 |
169 and finally to close the plot |
169 and finally to close the plot |
170 In []: close() |
170 In []: close() |
171 |
171 |
172 In this tutorial You learned |
172 In this tutorial we learned |
173 |
173 |
174 Ipython Features |
174 Some IPython Features |
175 Tab for autocompletion. |
175 Starting and exiting. |
176 function? to look at documention |
176 autocompletion. |
177 q to quit documentation. |
177 help functionality. |
178 escapping from ... prompt using Ctrl -C |
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179 quitting ipython using Ctrl-D |
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180 |
178 |
181 The functions and commands you learnt were : |
179 Regarding plotting we covered: |
182 print for outping things |
180 How to create basic plots. |
183 linspace to create equally space points |
181 Adding labels, legends annotation etc. |
184 plot to get a plot |
182 How to change looks of the plot like colors, linewidth formats etc |
185 xlabel to label x-axis of plot |
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186 ylabel to label y-axis of plot |
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187 title to title a plot |
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188 legend for placing appropriate legend |
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189 annotating a plot |
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190 saving a plot |
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191 multiple plots using figure |
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192 clearing plots using clf() |
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193 and last closing plot using close() |
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194 |
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195 |
183 |
196 **************** |
184 **************** |
197 This brings us to the end of this tutorial. This is the first tutorial in a series of tutorials on Python for Scientific Computing. This tutorial is created by the FOSSEE team, IIT Bombay. Hope you enjoyed it and found it useful. |
185 This brings us to the end of this tutorial. This is the first tutorial in a series of tutorials on Python for Scientific Computing. This tutorial is created by the FOSSEE team, IIT Bombay. Hope you enjoyed it and found it useful. |
198 **************** |
186 **************** |
199 |
187 |
200 ************ |
188 ************ |
201 A slide of review of what has been covered and sequentially/rapidly going through them. |
189 A slide of review of what has been covered and sequentially/rapidly going through them. |
202 ************ |
190 ************ |
203 |
191 |
204 Various problems of Ipython, navigation and enter, exit. |
192 Various problems of Ipython, navigation and enter, exit. |
|
193 What about xlim and ylim? |