matplotlib scatter fails with error: 'c' argument has n elements, which is not acceptable for use with 'x' with size n, 'y' with size n

Question

我正在尝试使用 matplotlib 创建散点图，其中每个点都有特定的颜色值。

我缩放值，然后在 'left' 和 'right' 颜色之间应用 alpha 混合。

# initialization
from matplotlib import pyplot as plt
from sklearn.preprocessing import MinMaxScaler
import numpy as np

values = np.random.rand(1134)

# actual code
colorLeft = np.array([112, 224, 112])
colorRight = np.array([224, 112, 112])
scaled = MinMaxScaler().fit_transform(values.reshape(-1, 1))
colors = np.array([a * colorRight + (1 - a) * colorLeft for a in scaled], dtype = np.int64)
# check values here
f, [sc, other] = plt.subplots(1, 2)
sc.scatter(np.arange(len(values)), values, c = colors)

然而最后一行给出了错误：

'c' argument has 1134 elements, which is not acceptable for use with 'x' with size 1134, 'y' with size 1134

scatter documentation表示参数c

c : color, sequence, or sequence of color, optional

The marker color. Possible values:

  A single color format string.
  A sequence of color specifications of length n.
  A sequence of n numbers to be mapped to colors using cmap and norm.
  A 2-D array in which the rows are RGB or RGBA.

我想使用最后一个选项和 RGB 值。

我用一些打印语句替换了 check values here 注释：

print(values)
print(colors)
print(values.shape)
print(colors.shape)

给出了结果：

[0.08333333 0.08333333 0.08333333 ... 1.         1.         1.08333333]
[[112 224 112]
 [112 224 112]
 [112 224 112]
 ...
 [214 121 112]
 [214 121 112]
 [224 111 112]]
(1134,)
(1134, 3)

Answer 1

将颜色转换为 0 <= 颜色 <= 1 的浮点数组，它应该可以正常工作。

sc.scatter(np.arange(len(values)), values, c = colors/255)

matplotlib scatter fails with error: 'c' argument has n elements, which is not acceptable for use with 'x' with size n, 'y' with size n

matplotlib scatter fails with error: 'c' argument has n elements, which is not acceptable for use with 'x' with size n, 'y' with size n

python

matplotlib

scatter-plot