在PyPlot中反转Y轴

问题:在PyPlot中反转Y轴

我有一个带有一堆随机x,y坐标的散点图。当前,Y轴从0开始并上升到最大值。我希望Y轴从最大值开始,一直到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)

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)

回答 0

有一个新的API使它变得更加简单。

plt.gca().invert_xaxis()

和/或

plt.gca().invert_yaxis()

There is a new API that makes this even simpler.

plt.gca().invert_xaxis()

and/or

plt.gca().invert_yaxis()

回答 1

DisplacedAussie的答案是正确的,但是通常更短的方法是使有问题的单个轴反转:

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

gca()函数返回当前的Axes实例并[::-1]反转列表。

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.


回答 2

使用matplotlib.pyplot.axis()

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

因此,您可以在末尾添加以下内容:

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

尽管您可能希望在每一端进行填充,以免极端点位于边界上。

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.


回答 3

如果您在ipython pylab模式下,则

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

show()要求,使其更新当前的身影。

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.


回答 4

您还可以使用散点图的轴对象公开的功能

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

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()

回答 5

与上述方法类似的另一种方法是plt.ylim例如使用:

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

当我尝试在Y1和/或Y2上复合多个数据集时,此方法对我有用

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


回答 6

使用ylim()可能是达到您目的的最佳方法:

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

将导致:

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:


回答 7

另外,您可以使用matplotlib.pyplot.axis()函数,该函数可以反转任何绘图轴

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

或者,如果您只想反转X轴,则

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

实际上,您可以反转两个轴:

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

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]))

回答 8

如果使用matplotlib,则可以尝试: matplotlib.pyplot.xlim(l, r) matplotlib.pyplot.ylim(b, t)

这两行分别设置x和y轴的极限。对于x轴,第一个参数l设置最左边的值,第二个参数r设置最右边的值。对于y轴,第一个参数b设置最低值,第二个参数t设置最高值。

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.