Reverse Y-Axis in PyPlot

Question

I have a scatter plot graph with a bunch of random x, y coordinates. Currently the Y-Axis starts at 0 and goes up to the max value. I would like the Y-Axis to start at the max value and go up to 0.

points = [(10,5), (5,11), (24,13), (7,8)]    
x_arr = []
y_arr = []
for x,y in points:
    x_arr.append(x)
    y_arr.append(y)
plt.scatter(x_arr,y_arr)

the amount of correct answers to this questions just shows how confusing this library is in use — g_uint, Nov 03 '21 at 10:15
@g_uint Since at least 10 years there is *one* obvious way and that is calling the `invert_yaxis()` method. — BlackJack, Dec 01 '21 at 22:49
@BlackJack what is obvious to you might not be obvious to another :) — g_uint, Dec 02 '21 at 08:46

score 712 · Accepted Answer · answered Nov 26 '11 at 18:12

712

There is a new API that makes this even simpler.

plt.gca().invert_xaxis()

and/or

plt.gca().invert_yaxis()

answered Nov 26 '11 at 18:12

Demitri

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Be aware that you have to set the axis limits *before* you invert the axis, otherwise it will un-invert it again. – TheBigH Jan 22 '16 at 15:56
Would sure be nice if it took a Boolean argument. When called repeatedly, you're just flipping it back and forth. – Mastiff Feb 09 '21 at 18:13

score 77 · Answer 2 · edited May 23 '17 at 11:47

77

DisplacedAussie's answer is correct, but usually a shorter method is just to reverse the single axis in question:

plt.scatter(x_arr, y_arr)
ax = plt.gca()
ax.set_ylim(ax.get_ylim()[::-1])

where the gca() function returns the current Axes instance and the [::-1] reverses the list.

edited May 23 '17 at 11:47

Community

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answered Jan 12 '10 at 22:04

Tim Whitcomb

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That seems like a better answer to me. :) – DisplacedAussie Jan 12 '10 at 23:07

score 38 · Answer 3 · answered Jul 03 '19 at 20:30

38

You could also use function exposed by the axes object of the scatter plot

scatter = plt.scatter(x, y)
ax = scatter.axes
ax.invert_xaxis()
ax.invert_yaxis()

answered Jul 03 '19 at 20:30

ShikharDua

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I was wondering why my 3D wireframe was not giving me the same date as the map. Invert the x axis. – pierre Feb 23 '21 at 17:16

score 23 · Answer 4 · answered Jan 12 '10 at 20:42

23

Use matplotlib.pyplot.axis()

axis([xmin, xmax, ymin, ymax])

So you could add something like this at the end:

plt.axis([min(x_arr), max(x_arr), max(y_arr), 0])

Although you might want padding at each end so that the extreme points don't sit on the border.

answered Jan 12 '10 at 20:42

DisplacedAussie

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This has an advantage over the first two answers that it fixes the orientation, not flip it every time (which is an issue if you need to call it in a loop). – Bas Swinckels Aug 04 '19 at 14:45

score 22 · Answer 5 · edited Oct 25 '13 at 07:55

22

If you're in ipython in pylab mode, then

plt.gca().invert_yaxis()
show()

the show() is required to make it update the current figure.

edited Oct 25 '13 at 07:55

answered Oct 11 '12 at 14:34

charles.fox

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score 9 · Answer 6 · answered May 27 '15 at 07:26

9

Another similar method to those described above is to use plt.ylim for example:

plt.ylim(max(y_array), min(y_array))

This method works for me when I'm attempting to compound multiple datasets on Y1 and/or Y2

answered May 27 '15 at 07:26

Mortsde

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score 6 · Answer 7 · answered Mar 24 '17 at 12:30

6

using ylim() might be the best approach for your purpose:

xValues = list(range(10))
quads = [x** 2 for x in xValues]
plt.ylim(max(quads), 0)
plt.plot(xValues, quads)

will result:

answered Mar 24 '17 at 12:30

Farzad Vertigo

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score 3 · Answer 8 · answered Sep 10 '15 at 12:53

Alternatively, you can use the matplotlib.pyplot.axis() function, which allows you inverting any of the plot axis

ax = matplotlib.pyplot.axis()
matplotlib.pyplot.axis((ax[0],ax[1],ax[3],ax[2]))

Or if you prefer to only reverse the X-axis, then

matplotlib.pyplot.axis((ax[1],ax[0],ax[2],ax[3]))

Indeed, you can invert both axis:

matplotlib.pyplot.axis((ax[1],ax[0],ax[3],ax[2]))

score 0 · Answer 9 · answered Sep 06 '19 at 09:16

If using matplotlib you can try: matplotlib.pyplot.xlim(l, r) matplotlib.pyplot.ylim(b, t)

These two lines set the limits of the x and y axes respectively. For the x axis, the first argument l sets the left most value, and the second argument r sets the right most value. For the y axis, the first argument b sets the bottom most value, and the second argument t sets the top most value.

score 0 · Answer 10 · answered Nov 14 '21 at 05:17

If using matplotlib we can make plot in reverse y axis in these 3 different ways: 1.By Specifying ymaximum value as y_min and yminimum as y_max

plt.xlim(x_min,x_max)
plt.ylim(y_min,y_max)
plt.xlim(0, 80)
plt.ylim(100, 0)

Specifying axis

plt.axis([x_min, x_max, y_min, y_max]) plt.axis([0, 80, 100, 0])

3.Using gca()function of matplotlib and calling invert_yaxis()function

ax = plt.gca()
ax.invert_yaxis()

Reverse Y-Axis in PyPlot

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