Difference between revisions of "Matplotlib"
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Line 6: | Line 6: | ||
:Initialize a new figure. figure(1) is initialized by default. | :Initialize a new figure. figure(1) is initialized by default. | ||
;plt.subplot(211) | ;plt.subplot(211) | ||
− | :Create 1st subplot in figure(1) (212 is the 2nd subplot in figure(1) | + | :Create 1st subplot in figure(1) (212 is the 2nd subplot in figure(1). Return an 'AxesSubplot' object. |
:211 : Split the figure in 2, figure(1) subplot 1 | :211 : Split the figure in 2, figure(1) subplot 1 | ||
+ | :The subplot can be specified as 2,1,1 too which comes in handy when you have to generate subplots on the fly. | ||
+ | ;fig,ax = plt.subplots() | ||
+ | :Return Figure and AxeSubPlot object. Same as: | ||
+ | :<code>fig = plt.figure()</code> | ||
+ | :<code>ax = fig.add_subplot(111)</code> | ||
;plt.plot(array) | ;plt.plot(array) | ||
:Create the graphical object from the values in the array. Show the graph if your environment (e.g. [https://jupyter.org/ jupyter]) supports it. | :Create the graphical object from the values in the array. Show the graph if your environment (e.g. [https://jupyter.org/ jupyter]) supports it. | ||
:When you do more plots without changing figure or subplot the result will be added to the current figure. | :When you do more plots without changing figure or subplot the result will be added to the current figure. | ||
+ | ;plt.legend() | ||
+ | :Add a legend to the plot. Default legend is the label, specify an alternative legend text as list. | ||
;plt.show() | ;plt.show() | ||
:Show the current figure. | :Show the current figure. | ||
− | + | ;plt.savefig('plot.png') | |
− | + | :Save the plot on file | |
+ | Show the image: | ||
+ | <syntaxhighlight lang=bash> | ||
+ | firefox plot.png | ||
+ | eog plot.png | ||
+ | shotwell plot.png | ||
+ | </syntaxhighlight> | ||
Selfexplaning example code: | Selfexplaning example code: | ||
<syntaxhighlight lang=python> | <syntaxhighlight lang=python> | ||
Line 21: | Line 34: | ||
plt.xlabel('Set the x label') | plt.xlabel('Set the x label') | ||
plt.ylabel('Set the y label') | plt.ylabel('Set the y label') | ||
− | |||
plt.show() | plt.show() | ||
</syntaxhighlight> | </syntaxhighlight> | ||
+ | With subplots, more lines and legends | ||
+ | <syntaxhighlight lang=python> | ||
+ | ax = plt.subplot(111) | ||
+ | lineA = ax.plot(array,label='Alabel') | ||
+ | lineB = ax.plot(array,label='Blabel') | ||
+ | ax.legend() | ||
+ | </syntaxhighlight> | ||
+ | |||
+ | ==Formatting== | ||
+ | ;plt.plot | ||
+ | :Draw lines | ||
+ | ;plt.bar | ||
+ | :Draw bars | ||
+ | ;plt.scatter | ||
+ | :Draw points | ||
+ | All above take 2 lists at arguments, the first for the X-axis, the second for the Y-axis. When a labeled list like numpy arrays or pandas Series is provided the labels make the X, the values the Y. | ||
− | + | A next argument defines the format as <colorchar><format> | |
− | + | {| class="wikitable" | |
− | + | |+ Formatting strings | |
− | + | ! Format | |
− | + | ! Meaning | |
− | + | |- | |
+ | | b- | ||
+ | | Blue Solid line, the default | ||
+ | |- | ||
+ | | r-- | ||
+ | | Red Dashed line | ||
+ | |- | ||
+ | | b: | ||
+ | | Blue Dotted line | ||
+ | |- | ||
+ | | r. | ||
+ | | Red Dots | ||
+ | |- | ||
+ | | g-. | ||
+ | | Green dashes and dots | ||
+ | |- | ||
+ | | gb | ||
+ | | Green Squares | ||
+ | |- | ||
+ | | y^ | ||
+ | | Yellow Triangles | ||
+ | |- | ||
+ | | yo | ||
+ | | Yellow Balls | ||
+ | |} |
Revision as of 23:32, 23 December 2018
Using the pyplot functions only until now.
- import matplotlib.pyplot as plt
- Get the pyplot library. We assume this is done in all examples on this page.
- plt.figure(2)
- Initialize a new figure. figure(1) is initialized by default.
- plt.subplot(211)
- Create 1st subplot in figure(1) (212 is the 2nd subplot in figure(1). Return an 'AxesSubplot' object.
- 211 : Split the figure in 2, figure(1) subplot 1
- The subplot can be specified as 2,1,1 too which comes in handy when you have to generate subplots on the fly.
- fig,ax = plt.subplots()
- Return Figure and AxeSubPlot object. Same as:
fig = plt.figure()
ax = fig.add_subplot(111)
- plt.plot(array)
- Create the graphical object from the values in the array. Show the graph if your environment (e.g. jupyter) supports it.
- When you do more plots without changing figure or subplot the result will be added to the current figure.
- plt.legend()
- Add a legend to the plot. Default legend is the label, specify an alternative legend text as list.
- plt.show()
- Show the current figure.
- plt.savefig('plot.png')
- Save the plot on file
Show the image:
firefox plot.png
eog plot.png
shotwell plot.png
Selfexplaning example code:
plt.plot(array)
plt.suptitle('Set the graph tilte')
plt.xlabel('Set the x label')
plt.ylabel('Set the y label')
plt.show()
With subplots, more lines and legends
ax = plt.subplot(111)
lineA = ax.plot(array,label='Alabel')
lineB = ax.plot(array,label='Blabel')
ax.legend()
Formatting
- plt.plot
- Draw lines
- plt.bar
- Draw bars
- plt.scatter
- Draw points
All above take 2 lists at arguments, the first for the X-axis, the second for the Y-axis. When a labeled list like numpy arrays or pandas Series is provided the labels make the X, the values the Y.
A next argument defines the format as <colorchar><format>
Format | Meaning |
---|---|
b- | Blue Solid line, the default |
r-- | Red Dashed line |
b: | Blue Dotted line |
r. | Red Dots |
g-. | Green dashes and dots |
gb | Green Squares |
y^ | Yellow Triangles |
yo | Yellow Balls |