View source for Python-3.4.3/C2/Saving-plots/English-timed


{| border=1
| '''Time'''
| '''Narration'''

|-
|00:01
| Hello friends! Welcome to the tutorial on "'''Saving Plots'''". 

|-
| 00:06
| At the end of this tutorial, you will be able to -

save '''plot'''s using '''savefig() function''',

save plots in different '''format'''s.

|-
| 00:15
|To record this tutorial, I am using: 

'''Ubuntu Linux 14.04''' operating system,

'''Python 3.4.3''',

'''IPython 5.1.0'''

|-
| 00:28
| To practise this tutorial, you should know how to use '''Plot''' command interactively.

If not, see the prerequisite '''Python tutorials''' on this website.

|-
| 00:40
| Let us first open the '''Terminal '''by pressing '''Ctrl+Alt+T '''keys simultaneously. 
Now, type '''ipython3''' and press '''Enter'''. 

|-
| 00:54
| Let us initialise the ''''pylab' package'''.
Type '''percentage pylab '''and press''' Enter'''.

|-
| 01:05
| Let us plot a '''sine curve''' from''' minus 3 pi''' to '''3 pi. '''

|-
| 01:10
| First, we will calculate the required points for the plot. 

|-
| 01:14
| To do this, type:

'''x equals to linspace(minus 3 star pi comma 3 star pi comma 100) '''in the '''console'''.

|-
| 01:28
| Let us '''plot''' a '''sine curve''' for the points stored in '''variable x'''.

|-
| 01:33
| Type: '''plot(x comma sin(x)) '''in the '''console''' and press '''Enter. '''

Don't close the '''plot window''' for rest of the tutorial.

|-
| 01:47
| Here you can see we have made a very basic '''sine plot'''. Now let us see how to '''save''' the '''plot.'''

|-
| 01:54
| For saving the plot, we will use the ''''savefig()' function.''' 

Syntax: '''savefig(fname)'''

'''savefig function''' takes one '''argument''' which is the filename. 

|-
| 02:05
| Type: '''savefig('sine.png') '''and press''' Enter'''.

|-
| 02:12
| This saves the file in present '''working directory'''.

|-
| 02:16
| The characters after the '''dot '''in the filename is the '''extension'''. It determines the '''format''' in which you want to '''save''' the file.

|-
| 02:27
| To check the current working directory, type '''pwd '''in the '''console''' and press '''Enter'''.

|-
| 02:34
| To save the file in a different directory, type full '''path''' of the directory before the filename.
Type: '''savefig('slash home slash fossee slash sine.png')'''

|-
| 02:53
| Note that the above''' file path '''is for''' Linux''' based file systems.

|-
| 02:59
| For''' Windows, '''give the entire '''file path''' as shown here. Here '''fossee''' is the '''username '''in''' Windows''' and '''sine.png '''file is to be saved on '''Desktop'''.

|-
| 03:15
| Here we have used an '''extension dot png.''' This will ensure that the image is saved as a '''PNG''' file.

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| 03:24
| Now let us locate the file '''sine.png''' which we had saved earlier. 

|-
| 03:30
| We have saved the file to 

'''(slash)home(slash)fossee'''.

|-
| 03:35
| Let us navigate to '''(slash)home(slash)fossee''' using the file browser. 

|-
|03:40
| Open the '''sine.png '''file to see the plotted '''sine curve. '''

|-
| 03:46
| '''savefig''' can save the plot in many formats such as-

'''pdf - portable document format, '''

'''ps - post script, '''

|-
| 03:57
| '''eps - encapsulated post script, '''to be used with '''LaTeX '''documents,

'''svg - scalable vector graphics, '''

'''.png - portable network graphics '''.

|-
| 04:10
| Pause the video here, try out the following exercise and resume the video.

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| 04:16
| Save the '''sine plot''' in the '''eps format'''.  Let us see the output for this exercise.

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| 04:23
| Type: '''savefig('slash home slash fossee slash sine.eps')''' and press '''Enter.'''

|-
| 04:35
| Now let us go to '''slash home slash fossee''' and see the new file created. We see the file '''sine.eps''' here.

|-
| 04:48
| Pause the video here, try out the following exercise and resume the video.
Save the '''sine plot''' in '''PDF, PS''' and '''SVG formats'''.

|-
| 05:00
| This brings us to the end of this tutorial. In this tutorial, we have learnt to:

1. Save plots using the '''savefig() '''function.

2. Save the plots in different formats like
''' pdf, ps, png, svg''' and '''eps'''.

|-
| 05:17
| Here are some assignment questions for you to solve.

1. Which command is used to save a '''plot'''?
'''saveplot()''',

'''savefig()''',

'''savefigure()''',

'''saveplt()'''

2. '''savefig('sine.png')''' saves the '''plot''' in-
 
the '''root directory 'slash' (on GNU/Linux, Unix based systems), '<u>C</u>:' (on windows)''',

|-
| 05:40
|will result in an '''error''' as '''full path''' is not supplied,

the current '''working directory''',

predefined directory like “'''slash documents.”'''

|-
| 05:50
| And the answers are-

1. To save a plot, we use the '''savefig() function.'''

2. If we save a file without complete path,  it gets saved in the current '''working directory'''.

|-
| 06:02
|Please post your timed questions in this forum.

|-
| 06:07
|Please post your general queries on '''Python''' in this forum.

|-
| 06:12
|'''FOSSEE''' team coordinates the '''TBC project'''.

|-
| 06:16
| '''Spoken Tutorial''' project is funded by '''NMEICT, MHRD,''' Govt. of India. For more details, visit this website.

|-
| 06:25
| This is Prabhu from '''IIT Bombay''', signing off. Thank you.

|}