other:python:jyp_steps
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other:python:jyp_steps [2019/06/03 16:12] jypeter [Useful matplotlib reference pages] Added animations |
other:python:jyp_steps [2019/06/03 16:32] jypeter [Matplotlib] improved |
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| The matplotlib documentation is good, but not always easy to use. <wrap hi>A good way to start with matplotlib</wrap> is to quickly read the following, practice, and read this section again | The matplotlib documentation is good, but not always easy to use. <wrap hi>A good way to start with matplotlib</wrap> is to quickly read the following, practice, and read this section again | ||
| - Have a quick look at the [[https://matplotlib.org/gallery/index.html|matplotlib gallery]] to get an idea of all you can do with matplotlib. Later, when you need to plot something, go back to the gallery to find some examples that are close to what you need and click on them to view their source code | - Have a quick look at the [[https://matplotlib.org/gallery/index.html|matplotlib gallery]] to get an idea of all you can do with matplotlib. Later, when you need to plot something, go back to the gallery to find some examples that are close to what you need and click on them to view their source code | ||
| - | * some examples are more //pythonic// (ie object oriented) than others, some example mix different styles of coding, all this can be confusing. Try to [[http://matplotlib.org/faq/usage_faq.html#coding-styles|use an object oriented way of doing things]]! | + | * some examples are more //pythonic// (ie object oriented) than others, and some examples mix different styles of coding, which can be quite confusing. Try to [[http://matplotlib.org/faq/usage_faq.html#coding-styles|use an object oriented way of doing things]]! |
| - Use the free hints provided by JY! | - Use the free hints provided by JY! | ||
| - You will usually **initialize matplotlib** with: ''import matplotlib.pyplot as plt'' | - You will usually **initialize matplotlib** with: ''import matplotlib.pyplot as plt'' | ||
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| * later, you may need other matplotlib related modules, for advanced usage | * later, you may need other matplotlib related modules, for advanced usage | ||
| - You need to know some **matplotlib specific vocabulary**: | - You need to know some **matplotlib specific vocabulary**: | ||
| - | * a Matplotlib **//Figure//** (or //canvas//) is a graphical window in which you create your plots... | + | * a Matplotlib **//Figure//** (or //canvas//) is a **graphical window** in which you create your plots... |
| * example: ''my_page = plt.figure()'' | * example: ''my_page = plt.figure()'' | ||
| - | * if you need several display windows at the same time, create several figures | + | * if you need several display windows at the same time, create several figures!\\ <code>win_1 = plt.figure() |
| + | win_2 = plt.figure()</code> | ||
| * the [[http://matplotlib.org/faq/usage_faq.html#parts-of-a-figure|parts of a figure]] are often positioned in //normalized coordinates//: ''(0, 0)'' is the bottom left of the figure, and ''(1, 1)'' the top right | * the [[http://matplotlib.org/faq/usage_faq.html#parts-of-a-figure|parts of a figure]] are often positioned in //normalized coordinates//: ''(0, 0)'' is the bottom left of the figure, and ''(1, 1)'' the top right | ||
| * You don't really specify the **page orientation** (//portrait// or //landscape//) of a plot. If you want a portrait plot, it's up to you to create a plot that will look higher than it is large. The idea is not to worry about this and just check the final resulting plot: create a plot, save it, display the resulting png/pdf and then adjust the creation script | * You don't really specify the **page orientation** (//portrait// or //landscape//) of a plot. If you want a portrait plot, it's up to you to create a plot that will look higher than it is large. The idea is not to worry about this and just check the final resulting plot: create a plot, save it, display the resulting png/pdf and then adjust the creation script | ||
| - | * If you have an idea of the layout of what you want to plot, it may be easier to explicitly specify the figure size/ratio at creation time, and try to //fill// the figure | + | * If you do have an idea of the layout of what you want to plot, it may be easier to explicitly specify the figure size/ratio at creation time, and then try to //fill// the normalized coordinates space of the figure |
| * ''my_page = plt.figure()'': the ratio of the default figure is ''landscape'', because it is 33% larger than it is high. Creating a default figure will be OK most of the time! | * ''my_page = plt.figure()'': the ratio of the default figure is ''landscape'', because it is 33% larger than it is high. Creating a default figure will be OK most of the time! | ||
| * ''my_page = plt.figure(figsize=(width, height))'': create a figure with a custom ratio (sizes are considered to be in inches) | * ''my_page = plt.figure(figsize=(width, height))'': create a figure with a custom ratio (sizes are considered to be in inches) | ||
| - | * ''my_page = plt.figure(figsize=(8.3, 11.7))'': create a figure that will theoretically fill an A4 size page in portrait mode (check [[https://www.papersizes.org/a-paper-sizes.htm|Dimensions Of A Series Paper Sizes]] if you need more size details) | + | * ''my_page = plt.figure(figsize=(8.3, 11.7))'': create a figure that will theoretically fill an A4 size page in portrait mode (check [[https://www.papersizes.org/a-paper-sizes.htm|Dimensions Of A Series Paper Sizes]] if you need more size details) |
| - | * a Matplotlib **//Axis//** is a plot inside a Figure... [[http://matplotlib.org/faq/usage_faq.html#parts-of-a-figure|More details]] | + | * a Matplotlib **//Axis//** is a **plot** inside a Figure... [[http://matplotlib.org/faq/usage_faq.html#parts-of-a-figure|More details]] |
| * reserve space for **one plot** that will use most of the available area of the figure/page: | * reserve space for **one plot** that will use most of the available area of the figure/page: | ||
| * ''my_plot = my_page.add_subplot(1, 1, 1)'': syntax is ''add_subplot(nrows, ncols, index)'' | * ''my_plot = my_page.add_subplot(1, 1, 1)'': syntax is ''add_subplot(nrows, ncols, index)'' | ||
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| * creating a figure and axes with a single line: ''my_page, plot_array = **plt**.subplots(3, 1)'' | * creating a figure and axes with a single line: ''my_page, plot_array = **plt**.subplots(3, 1)'' | ||
| * a Matplotlib **//Artist//** or //Patch// is //something// (e.g a line, a group of markers, text, the legend...) plotted on the Figure/Axis | * a Matplotlib **//Artist//** or //Patch// is //something// (e.g a line, a group of markers, text, the legend...) plotted on the Figure/Axis | ||
| - | * **clearing** the //page// (or part of it): you probably won't need that | + | * **clearing** the //page// (or part of it): you probably won't need that... |
| * ''my_page.clear()'' or ''my_page.clf()'' or ''plt.clf()'': clear the (current) figure | * ''my_page.clear()'' or ''my_page.clf()'' or ''plt.clf()'': clear the (current) figure | ||
| * ''my_plot.clear()'' or ''my_plot.cla()'': clear the (current) axis | * ''my_plot.clear()'' or ''my_plot.cla()'': clear the (current) axis | ||
other/python/jyp_steps.txt · Last modified: 2024/03/07 10:15 by jypeter
