'c'参数看起来像单个数字RGB或RGBA序列

时间:2019-03-11 20:16:12

标签: python machine-learning jupyter-notebook

我的Juypter笔记本出现以下错误。我已经将mathplotlib更新到最新版本,但仍然收到错误

'c'参数看起来像一个单一的RGB或RGBA数字序列,应避免使用它,因为如果其长度与'x'和'y'匹配,则值映射将具有优先级。如果您确实想为所有点指定相同的RGB或RGBA值,请使用单行二维数组。

X=lab3_data
range_n_clusters = [2, 3, 4, 5, 6,7,8]

for n_clusters in range_n_clusters:
# Create a subplot with 1 row and 2 columns
fig, (ax1, ax2) = plt.subplots(1, 2)
fig.set_size_inches(18, 7)

# The 1st subplot is the silhouette plot
# The silhouette coefficient can range from -1, 1 but in this example all
# lie within [-0.1, 1]
ax1.set_xlim([0, 1])
# The (n_clusters+1)*10 is for inserting blank space between silhouette
# plots of individual clusters, to demarcate them clearly.
ax1.set_ylim([0, len(X) + (n_clusters + 1) * 10])

# Initialize the clusterer with n_clusters value and a random generator
# seed of 10 for reproducibility.
clusterer = cluster.KMeans(n_clusters=n_clusters, random_state=10)
cluster_labels = clusterer.fit_predict(X)

# The silhouette_score gives the average value for all the samples.
# This gives a perspective into the density and separation of the formed
# clusters
silhouette_avg = silhouette_score(X, cluster_labels)
print("For n_clusters =", n_clusters,
      "The average silhouette_score is :", silhouette_avg)

# Compute the silhouette scores for each sample
sample_silhouette_values = silhouette_samples(X, cluster_labels)

y_lower = 10
for i in range(n_clusters):
    # Aggregate the silhouette scores for samples belonging to
    # cluster i, and sort them
    ith_cluster_silhouette_values = \
        sample_silhouette_values[cluster_labels == i]

    ith_cluster_silhouette_values.sort()

    size_cluster_i = ith_cluster_silhouette_values.shape[0]
    y_upper = y_lower + size_cluster_i

    color = cm.nipy_spectral(float(i) / n_clusters)
    ax1.fill_betweenx(np.arange(y_lower, y_upper),
                      0, ith_cluster_silhouette_values,
                      facecolor=color, edgecolor=color, alpha=0.7)

    # Label the silhouette plots with their cluster numbers at the middle
    ax1.text(-0.05, y_lower + 0.5 * size_cluster_i, str(i))

    # Compute the new y_lower for next plot
    y_lower = y_upper + 10  # 10 for the 0 samples

ax1.set_title("The silhouette plot for the various clusters.")
ax1.set_xlabel("The silhouette coefficient values")
ax1.set_ylabel("Cluster label")

# The vertical line for average silhouette score of all the values
ax1.axvline(x=silhouette_avg, color="red", linestyle="--")

ax1.set_yticks([])  # Clear the yaxis labels / ticks
ax1.set_xticks([0, 0.2, 0.4, 0.6, 0.8, 1])

# 2nd Plot showing the actual clusters formed
# append the cluster centers to the dataset
lab3_data_and_centers = np.r_[lab3_data,clusterer.cluster_centers_]
# project both th data and the k-Means cluster centers to a 2D space
XYcoordinates = manifold.MDS(n_components=2).fit_transform(lab3_data_and_centers)
# plot the transformed examples and the centers
# use the cluster assignment to colour the examples
# plot the transformed examples and the centers
# use the cluster assignment to colour the examples

clustering_scatterplot(points=XYcoordinates[:-n_clusters,:], 
                       labels=cluster_labels,
                       centers=XYcoordinates[-n_clusters:,:], 
                       title='MDS')

plt.suptitle(("Silhouette analysis for KMeans clustering on sample data "
              "with n_clusters = %d" % n_clusters),
             fontsize=14, fontweight='bold')

plt.show()

5 个答案:

答案 0 :(得分:9)

您还可以使用以下命令将c参数设为2D:

    c=color.reshape(1,-1)

    c=np.array([color])

或仅将原始颜色阵列更改为2D:

    color = cm.nipy_spectral(float(i) / n_clusters).reshape(1,-1)

p.s .:由于我需要50点信誉才能发表评论,所以我只是打开一个新答案,尽管这只是D Adams使用内置numpy.atleast_2D()解决方案下的评论。

答案 1 :(得分:4)

首先产生数据并定义颜色:

import numpy
import matplotlib
import matplotlib.pyplot

#Make the color you actually want:
Color = numpy.array([.5, .6, .7])

#Make some data:
Vals = numpy.random.uniform( size = (10, 3) )
PointCount = Vals.shape[0]
Xvals = Vals[:, 0]
Yvals = Vals[:, 1]
Zvals = Vals[:, 2]

第二次重现该问题:

#2D: Produce the warning
fig = matplotlib.pyplot.figure() 
subplot = fig.add_subplot(111)
matplotlib.pyplot.scatter( Xvals, Yvals, c= Color,   )
'c' argument looks like a single numeric RGB or RGBA sequence, which should be avoided as value-mapping will have precedence in case its length matches with 'x' & 'y'.  Please use a 2-D array with a single row if you really want to specify the same RGB or RGBA value for all points.

第一个解决方案是制作所需颜色的副本:

#Illustrate how to repeat a numpy array:
ValsCount = Vals.shape[0]
ColorsRepeated = numpy.repeat(numpy.atleast_2d(Color), ValsCount, axis = 0)
print ('ColorsRepeated')
print (ColorsRepeated)

#2D: Make scatter plot without color warning using repeat
fig = matplotlib.pyplot.figure() 
subplot = fig.add_subplot(111)
matplotlib.pyplot.scatter( Xvals, Yvals, c= ColorsRepeated, )

#3D: Make scatter plot without color warning using repeat
fig = matplotlib.pyplot.figure() 
subplot = fig.add_subplot(111, projection='3d')
matplotlib.pyplot.scatter( Xvals,  Yvals, Zvals, c=ColorsRepeated,  )
ColorsRepeated
[[0.5 0.6 0.7]
 [0.5 0.6 0.7]
 [0.5 0.6 0.7]
 [0.5 0.6 0.7]
 [0.5 0.6 0.7]
 [0.5 0.6 0.7]
 [0.5 0.6 0.7]
 [0.5 0.6 0.7]
 [0.5 0.6 0.7]
 [0.5 0.6 0.7]]

另一种解决方案是使用matplotlib.pyplot.plot,它不会发出与matplotlib.pyplot.scatter相同的警告,您可以避免使用常规plot命令出现颜色重复问题,而不必连接点:

#2D: Make regular plot without using repeat
fig = matplotlib.pyplot.figure() 
subplot = fig.add_subplot(111)
matplotlib.pyplot.plot( Xvals, Yvals, c= Color, marker = '.', linestyle = '', )

另一种解决方案是使彩色二维阵列具有一行,以解决matplotlib.pyplot.scatter的问题,但引发matplotlib.pyplot.plot的错误:

#2D: Use single row in 2D array to avoid warning
fig = matplotlib.pyplot.figure() 
subplot = fig.add_subplot(111)
matplotlib.pyplot.scatter( Xvals,  Yvals, c= numpy.atleast_2d(Color), )

使用常规的matplotlib.pyplot.plot命令和2D彩色单行会引发错误:

#2D: Try and fail to use a single row in 2D array in a regular plot
fig = matplotlib.pyplot.figure() 
subplot = fig.add_subplot(111)
matplotlib.pyplot.plot( Xvals, Yvals,  c= numpy.atleast_2d(Color),  marker = '.', linestyle = '', )
ValueError: Invalid RGBA argument: array([[0.5, 0.6, 0.7]])

结论: matplotlib.pyplot.plotmatplotlib.pyplot.scatter在颜色方面表现不同。 matplotlib.pyplot.plot需要一维数组。 matplotlib.pyplot.scatter需要2D数组。 2D数组可以是单行,也可以重复,也可以是每个数据点不同的颜色。如果matplotlib社区添加if语句为我们做重复并删除警告,那就太好了。

答案 2 :(得分:1)

在最新版本的matplotlib(3.0.3)中,参数'c'应该是二维数组。如果'c'的长度与'x'和'y'的长度匹配,则每个点的颜色对应于'c'的元素。如果要使每个点显示相同的颜色,则'c'应该是具有单个行的二维数组,例如c = np.array([0.5,0.5,0.5])。 最好的祝福!

答案 3 :(得分:0)

作为解决方法:

 from matplotlib.axes._axes import _log as matplotlib_axes_logger
 matplotlib_axes_logger.setLevel('ERROR')

答案 4 :(得分:0)

 c=np.array([0.5, 0.5, 0.5]).reshape(1,-1)