使用matplotlib下降x轴值

Question

如何绘制条形图，其中x轴值从最高到最低的降序排列？

示例：

例如，我的情节如下：

我需要图表来分类星期一（最高值），星期三，星期二（最小值）（分别）的位置

这是我到目前为止所拥有的：

x_axis = ['a','b','c'...'z']
y_axis = [#...#...#] number values for each letter in xaxis

def barplot(x_axis, y_axis): #x and y axis defined in another function
    x_label_pos = range(len(y_axis))
    plot.bar(x_label_pos, y_axis)
    plot.yticks(range(0, int(max(y_axis) + 2), 2))
    plot.xticks(x_axis) 

Answer 1

# grab a reference to the current axes
ax = plt.gca()
# set the xlimits to be the reverse of the current xlimits
ax.set_xlim(ax.get_xlim()[::-1])
# call `draw` to re-render the graph
plt.draw()

matplotlib将做正确的事情＆＃39;如果设置x限制，左边的值大于正确的值（和y轴相同）。

Answer 2

以下是一个可以满足您需求的最小示例。您的问题实际上与matplotlib无关，但只是根据需要重新排序您的输入数据。

import matplotlib.pyplot as plt

# some dummy lists with unordered values 
x_axis = ['a','b','c']
y_axis = [1,3,2]

def barplot(x_axis, y_axis): 
    # zip the two lists and co-sort by biggest bin value         
    ax_sort = sorted(zip(y_axis,x_axis), reverse=True)
    y_axis = [i[0] for i in ax_sort]
    x_axis = [i[1] for i in ax_sort]

    # the above is ugly and would be better served using a numpy recarray

    # get the positions of the x coordinates of the bars
    x_label_pos = range(len(x_axis))

    # plot the bars and align on center of x coordinate
    plt.bar(x_label_pos, y_axis,align="center")

    # update the ticks to the desired labels
    plt.xticks(x_label_pos,x_axis)


barplot(x_axis, y_axis)
plt.show()