# Pyplot axis fill between

In this article, we are going to learn how to fill the area of any figure with color in matplotlib using Python. For this, we need some basic concept of two popular modules of Python in the world of plotting figure or any diagram i. Let us see with some examples In the above example, first, we imported two required module named as matplotlib and numpy by writing these two lines of codes The explanation for the above example is as same as the first example.

This site uses cookies: Find out more. Okay, thanks.John Hunter Excellence in Plotting Contest submissions are open! Entries are due June 1, Click here to download the full example code. The parameters y1 and y2 can be a scalar, indicating a horizontal boundary a the given y-values.

If only y1 is given, y2 defaults to 0. These may be a bit strong when applied to fill areas.

It is therefore often a good practice to lighten the color by making the area semi-transparent using alpha. The parameter where allows to specify the x-ranges to fill. It's a boolean array with the same size as x. Only x-ranges of contiguous True sequences are filled. As a result the range between neighboring True and False values is never filled. This often undesired when the data points should represent a contiguous quantity. Interpolation approximates the actual x position at which the where condition will change and extends the filling up to there.

Similar gaps will occur if y1 or y2 are masked arrays. Since missing values cannot be approximated, interpolate has no effect in this case.

The gaps around masked values can only be reduced by adding more data points close to the masked values. The same selection mechanism can be applied to fill the full vertical height of the axes. To be independent of y-limits, we add a transform that interprets the x-values in data coorindates and the y-values in axes coordinates.

Keywords: matplotlib code example, codex, python plot, pyplot Gallery generated by Sphinx-Gallery. Version 3. Table of Contents Filling the area between lines Basic usage Example: Confidence bands Selectively filling horizontal regions Selectively marking horizontal regions across the whole Axes References Related Topics Documentation overview.

Show Page Source. Note Click here to download the full example code. Note Similar gaps will occur if y1 or y2 are masked arrays. The following example marks the regions in which the y-data are above a given threshold.Using PyLab is discouraged now.

All example notebooks can be found on this link. It can be used both within a Python system via the object-oriented API but also in more convenient form in Jupyter and IPython notebooks via the Pyplot interface. Simplest possible example: scatter function from pyplot namespace.

Someone had the idea of combining both the PyPlot and NumPy namespaces into a single one to avoid having to import two namespacesthe result is PyLab. Functions like scatter from pyplot are available when you import pylab too. Same image as above, resized. We used the plt. Same as with plt. Note that the y-axis now ranges from -3 to 3. We got a reference to the current axis by calling plt. These methods are used to clear the current figure plt.

It's common to call these methods just before defining a chart so that previous plots don't interfere with the next ones. All functions available in the PyPlot namespace. Felipe 26 Sep 31 Aug python data-visualization data-newsletter COM Home. Table of Contents. Related content.By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service.

It only takes a minute to sign up. For my other plots I was fine using the shading with coordinates because they were all polygons. I've come across a bunch of threads with similar situations but didn't see anything quite similar enough for me to copy and manipulate the code.

I The image below is exactly how I want it with the clear exception of the shading outside the box. The first and second answers below are perfect. What if I wanted the shaded area under the curve to stop at a certain y-value, instead of extending all the way down to the x-axis?

This can be done by means of the fillbetween library which has been introduced in pgfplots 1.

### Matplotlib, Pyplot, Pylab etc: What's the difference between these and when to use each?

The basic idea is to have two labelled input paths, in our case the function as such and the path which resembles the other boundary in our case the part of the axis from 0 to 1. The fill between library can also draw intersection segments individually. Clearly, this results in two segments. Another approach is to clip and fill the plot twice. In this case you have to identify curves with a name path and after that plot fill area between them.

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Home Questions Tags Users Unanswered. Pgfplots: how to fill bounded area under a curve using addplot and fill?

Email Required, but never shown. The Overflow Blog.By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service. The dark mode beta is finally here. Change your preferences any time. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information.

I want to create a plot just like this:. It would help if you show how df is defined. What does df.

### How to Fill area with color in matplotlib with Python

This will show us the dtypes of the columns. There are many ways that dates can be represented: as strings, ints, floats, datetime. The correct way to plot it depends on what you have. If the index has string representations of dates, then with Matplotlib version 1.

However, in my case the cause of error was rather stupid. I was passing color parameter but without explicit argument name which caused it to be 4 parameter called where. So simply making sure keyword parameters has key solved the issue:. Changing the example column types and then trying to plot, as follows, results in the error above:. Ensuring that the DataFrame has numerical columns will solve the problem.

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## Matplotlib Ribbon Plot (fill_between) with a Categorical X-Axis

Change your preferences any time. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. The attached picture shows the output produced. I've done Google and StackOverflow searches, but could not find a similar example. Intuitively it seems that it should fill the entire area under the curve. Try something like this instead:. See more examples here. Learn more. Filling region between curve and x-axis in Python using Matplotlib Ask Question.

Asked 6 years, 4 months ago. Active 1 year, 4 months ago. Viewed 10k times. I am trying to simply fill the area under the curve of a plot in Python using MatPlotLib. Does anyone know why Python is not filling the entire area in between the x-axis and the curve? Saullo G. Castro Active Oldest Votes. Try something like this instead: import numpy as np import matplotlib. Fermi paradox 3, 6 6 gold badges 35 35 silver badges 61 61 bronze badges. Trond Kristiansen Trond Kristiansen 1, 17 17 silver badges 39 39 bronze badges.

If you want to use this on a pd. DataFrameuse this: df. Steve Barnes Steve Barnes I see now, that makes sense.

So the 'fill function' is for filling the region within closed polygons. I am curious if there is no simpler way to do this than creating extra lists which have to be the length of your data. This feature is high in demand. Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. The Overflow Blog. Podcast Programming tutorials can be a real drag.I have a list of x and y values for two curves, both having weird shapes, and I don't have a function for any of them.

I need to do two things: 1 plot it and shade the area between the curves like the image below; 2 find the total area of this shaded region between the curves. I looked everywhere and can't find a simple solution for this. I'm quite desperate, so any help is much appreciated.

Works like a charm, ran for thousands of curves already. Define your two curves as functions f and g that are linear by segment, e.

Intro to Data Analysis / Visualization with Python, Matplotlib and Pandas - Matplotlib Tutorial

Then use scipy. That way you don't need to bother about the intersections. It will do the "trapeze summing" suggested by ch41rmn automatically. The area calculation is straightforward in blocks where the two curves don't intersect: thats the trapezium as has been pointed out above. If you want to do it directly, you should handle the two cases separately. Here's a basic working example to solve your problem. First, I will start with some fake data:.

Now, the main code. Based on your plot, looks like you have y1 and y2 defined at the same X points. Then we define.

At these points, we want to calculate the x coordinate of the crossover. For simplicity, I will calculate x coordinates of the intersection of all segments of y. For places where the two curves don't intersect, they will be useless values, and we won't use them anywhere. This just keeps the code easier to understand.

That is your desired answer. As has been pointed out above, this will get more complicated if the both the y graphs were defined at different x points. If you want to test this, you can simply plot it in my test case, y range will be to Any ideas? Thank you very much! First, I will start with some fake data:! Save plot to image file instead of displaying it using Matplotlib Fill between x and baseline x position in Matplotlib How to make IPython notebook matplotlib plot inline.