为什么我会得到"属性错误:'元组'对象没有属性' savefig'"?

时间:2017-03-14 22:00:18

标签: python arrays numpy matplotlib attributeerror

编辑3/15/2017 12:00 PM CDT: 我已设法修复程序中的错误并按照设计完成程序。我要感谢berna1111和TigerhawkT3提交的答案,因为他们允许我完成这个程序。再次感谢Stack Overflow!

我试图将一系列数组构建的直方图(使用matplotlib用numpy和直方图制作的数组)保存为.png类型文件。我收到以下错误消息:

Traceback (most recent call last):
  File "C:/Users/Ryan/PycharmProjects/NWS/weather_data.py", line 475, in <module>
    figure1.savefig("{}_temperature.png".format(filename))
AttributeError: 'tuple' object has no attribute 'savefig'

错误引用的部分如下:

figure1 = plt.hist(temperature_graph_array, color="blue")
figure2 = plt.hist(feelslike_graph_array, color="blue")
figure3 = plt.hist(windspeed_graph_array, color="blue")
figure4 = plt.hist(windgustspeed_graph_array, color="blue")
figure5 = plt.hist(pressure_graph_array, color="blue")
figure6 = plt.hist(humidity_graph_array, color="blue")

figure1.savefig("{}_temperature.png".format(filename), format='png')
figure2.savefig("{}_feelslike.png".format(filename), format='png')
figure3.savefig("{}_windspeed.png".format(filename), format='png')
figure4.savefig("{}_windgustspeed.png".format(filename), format='png')
figure5.savefig("{}_pressure.png".format(filename), format='png')
figure6.savefig("{}_humidity.png".format(filename), format='png')

为什么我收到此错误,我该如何解决?如果有人能告诉我,我会非常感激。

注意:

  • 我做了一些谷歌搜索,发现了一些类似的错误,但没有一个数字被解释为元组。我不明白元组部分的来源。

  • &#34; _graph_array&#34;直方图创建步骤中的项目是10长,1高的维度数组。其中10个项目,指定为Float类型。

  • &#34;文件名&#34;保存步骤中的变量表示包含日期和时间的字符串。

2 个答案:

答案 0 :(得分:3)

来自documentation for matplotlib.pyplot.hist

  

返回值是一个元组(binspatchesn0)或([n1bins,...],{{ 1}},[patches0patches1,...])如果输入包含多个数据。

来自documentation for matplotlib.pyplot.savefig

  

保存当前数字。

看起来您应该像调用savefig一样拨打hist,而不是hist电话的结果。

plt.savefig("{}_temperature.png".format(filename), format='png')
...

答案 1 :(得分:2)

我已经调整了你的代码并冒昧地改变了几行,以便在理解for循环时按列表创建一个数字:

import matplotlib.pyplot as plt
# should be equal when using .pylab
import numpy.random as rnd

# generate_data
n_points = 1000
temperature_graph_array = rnd.random(n_points)
feelslike_graph_array = rnd.random(n_points)
windspeed_graph_array = rnd.random(n_points)
windgustspeed_graph_array = rnd.random(n_points)
pressure_graph_array = rnd.random(n_points)
humidity_graph_array = rnd.random(n_points)
list_of_data = [temperature_graph_array,
                feelslike_graph_array,
                windspeed_graph_array,
                windgustspeed_graph_array,
                pressure_graph_array,
                humidity_graph_array]
list_of_names = ['temperature',
                 'feelslike',
                 'windspeed',
                 'windgustspeed',
                 'pressure',
                 'humidity']

# create the figures:
#figure1 = plt.figure()
#figure2 = plt.figure()
#figure3 = plt.figure()
#figure4 = plt.figure()
#figure5 = plt.figure()
#figure6 = plt.figure()
#list_of_figs = [figure1, figure2, figure3, figure4, figure5, figure6]
## could be:
list_of_figs = [plt.figure() for i in range(6)]

# create the axis:
#ax1 = figure1.add_subplot(111)
#ax2 = figure2.add_subplot(111)
#ax3 = figure3.add_subplot(111)
#ax4 = figure4.add_subplot(111)
#ax5 = figure5.add_subplot(111)
#ax6 = figure6.add_subplot(111)
#list_of_axis = [ax1, ax2, ax3, ax4, ax5, ax6]
## could be:
list_of_axis = [fig.add_subplot(111) for fig in list_of_figs]

# plot the histograms
# notice `plt.hist` returns a tuple (n, bins, patches) or
# ([n0, n1, ...], bins, [patches0, patches1,...]) if the input
# contains multiple data
#hist1 = ax1.hist(temperature_graph_array, color="blue")
#hist2 = ax2.hist(feelslike_graph_array, color="blue")
#hist3 = ax3.hist(windspeed_graph_array, color="blue")
#hist4 = ax4.hist(windgustspeed_graph_array, color="blue")
#hist5 = ax5.hist(pressure_graph_array, color="blue")
#hist6 = ax6.hist(humidity_graph_array, color="blue")
#list_of_hists = [hist1, hist2, hist3, hist4, hist5, hist6]
## could be:
list_of_hists = []
for i, ax in enumerate(list_of_axis):
    list_of_hists.append(ax.hist(list_of_data[i], color="blue"))

filename = 'output_graph'
for i, fig in enumerate(list_of_figs):
    name = list_of_names[i].capitalize()
    list_of_axis[i].set_title(name)
    fig.tight_layout()
    fig.savefig("{}_{}.png".format(filename,name), format='png')

不会发布结果数字,但这会在脚本相同的文件夹中提供6个.png文件。

更好的是,您可以使用一个函数来完成数据的所有操作:

def save_hist(data, name, filename):
    fig = plt.figure()
    ax = fig.add_subplot(111)
    ax.hist(data, color="blue")
    ax.set_title(name)
    fig.tight_layout()
    fig.savefig("{}_{}.png".format(filename,name), format='png')
    plt.close(fig)

filename = 'output_graph_2'
for data, name in zip(list_of_data, list_of_names):
    save_hist(data, name, filename)