海底热图的人工蜱标签

Question

我有一个seaborn热图,看起来像这样:

...从随机生成的值的pandas数据帧生成,其中一段看起来像这样:

沿y轴的值都在[0,1]范围内,而x轴上的值在[0,2*pi]范围内,我只需要定期为我的刻度标签设置一些短浮点数,但我似乎只能得到我的数据框中的值.当我尝试指定我想要的值时,它不会将它们放在正确的位置,如上图所示.他现在是我的代码.如何在正确的位置(沿轴均匀分布)中获取我尝试使用xticks和yticks指定的轴标签？

import pandas as pd
import numpy as np
import matplotlib as plt
from matplotlib.mlab import griddata

sns.set_style("darkgrid")
PHI, COSTH = np.meshgrid(phis, cos_thetas)
THICK = griddata(phis, cos_thetas, thicknesses, PHI, COSTH, interp='linear')

thick_df = pd.DataFrame(THICK, columns=phis, index=cos_thetas)
thick_df = thick_df.sort_index(axis=0, ascending=False)
thick_df = thick_df.sort_index(axis=1)

cmap = sns.cubehelix_palette(start=1.6, light=0.8, as_cmap=True, reverse=True)

yticks = np.array([0,0.2,0.4,0.6,0.8,1.0])

xticks = np.array([0,1,2,3,4,5,6])

g = sns.heatmap(thick_df, linewidth=0, xticklabels=xticks, yticklabels=yticks, square=True, cmap=cmap)

plt.show(g)

Answer 1

这是应该做你想做的事情:

cmap = sns.cubehelix_palette(start=1.6, light=0.8, as_cmap=True, reverse=True)

yticks = np.linspace(0,1,6)

x_end = 6
xticks = np.arange(x_end+1)

ax = sns.heatmap(thick_df, linewidth=0, xticklabels=xticks, yticklabels=yticks[::-1], square=True, cmap=cmap)

ax.set_xticks(xticks*ax.get_xlim()[1]/(2*math.pi))
ax.set_yticks(yticks*ax.get_ylim()[1])

plt.show()

你可以传递['{:,.2f}'.format(x) for x in xticks]而不是xticks来获得一个带有2位小数的浮点数.

请注意,我正在反转yticklabels,因为这就是seaborn的作用:参见matrix.py#L138.

Seaborn计算同一地点周围的刻度位置(例如:#L148),相当于:

# thick_df.T.shape[0] = thick_df.shape[1]
xticks: np.arange(0, thick_df.T.shape[0], 1) + .5
yticks: np.arange(0, thick_df.T.shape[1], 1) + .5