在Matplotlib中绘制多个直方图 - 颜色或并排条形图

Question

问题:在Matplotlib中绘制多个直方图时,我无法区分绘图与另一个绘图

图像问题:** **次要问题:部分左侧标签"计数"不在图像范围内.为什么？

描述

我想绘制3个不同组的直方图.每组都是一个0和1的数组.我想要每个的直方图,所以我可以检测数据集上的不平衡.

我让它们分开绘制,但我想要一起绘制它们的图形.

可以并排显示不同的图形,或者我甚至用谷歌搜索将其绘制为3D,但我不知道在图形上"阅读"或"查看"并理解它是多么容易.

现在,我想在同一图形的每一侧绘制[train],[validation]和[test]条形图,如下所示:

PS:我的谷歌搜索没有返回任何可以理解的代码.此外,我想如果有人会检查我是否对我的代码做了任何疯狂.

非常感谢!

代码:

def generate_histogram_from_array_of_labels(Y=[], labels=[], xLabel="Class/Label", yLabel="Count", title="Histogram of Trainset"):
    plt.figure()
    plt.clf()

    colors = ["b", "r", "m", "w", "k", "g", "c", "y"]

    information = []
    for index in xrange(0, len(Y)):
        y = Y[index]

        if index > len(colors):
            color = colors[0]
        else:
            color = colors[index]

        if labels is None:
            label = "?"
        else:
            if index < len(labels):
                label = labels[index]
            else:
                label = "?"

        unique, counts = np.unique(y, return_counts=True)
        unique_count = np.empty(shape=(unique.shape[0], 2), dtype=np.uint32)

        for x in xrange(0, unique.shape[0]):
            unique_count[x, 0] = unique[x]
            unique_count[x, 1] = counts[x]

        information.append(unique_count)

        # the histogram of the data
        n, bins, patches = plt.hist(y, unique.shape[0], normed=False, facecolor=color, alpha=0.75, range=[np.min(unique), np.max(unique) + 1], label=label)

    xticks_pos = [0.5 * patch.get_width() + patch.get_xy()[0] for patch in patches]

    plt.xticks(xticks_pos, unique)

    plt.xlabel(xLabel)
    plt.ylabel(yLabel)
    plt.title(title)
    plt.grid(True)
    plt.legend()
    # plt.show()

    string_of_graphic_image = cStringIO.StringIO()

    plt.savefig(string_of_graphic_image, format='png')
    string_of_graphic_image.seek(0)

    return base64.b64encode(string_of_graphic_image.read()), information

编辑

在哈希码的答案之后,这个新代码:

def generate_histogram_from_array_of_labels(Y=[], labels=[], xLabel="Class/Label", yLabel="Count", title="Histogram of Trainset"):
    plt.figure()
    plt.clf()

    colors = ["b", "r", "m", "w", "k", "g", "c", "y"]
    to_use_colors = []
    information = []


    for index in xrange(0, len(Y)):
        y = Y[index]

        if index > len(colors):
            to_use_colors.append(colors[0])
        else:
            to_use_colors.append(colors[index])

        unique, counts = np.unique(y, return_counts=True)
        unique_count = np.empty(shape=(unique.shape[0], 2), dtype=np.uint32)

        for x in xrange(0, unique.shape[0]):
            unique_count[x, 0] = unique[x]
            unique_count[x, 1] = counts[x]

        information.append(unique_count)

    unique, counts = np.unique(Y[0], return_counts=True)
    histrange = [np.min(unique), np.max(unique) + 1]
    # the histogram of the data
    n, bins, patches = plt.hist(Y, 1000, normed=False, alpha=0.75, range=histrange, label=labels)


    #xticks_pos = [0.5 * patch.get_width() + patch.get_xy()[0] for patch in patches]

    #plt.xticks(xticks_pos, unique)

    plt.xlabel(xLabel)
    plt.ylabel(yLabel)
    plt.title(title)
    plt.grid(True)
    plt.legend()

产生这个:

- 新编辑:

def generate_histogram_from_array_of_labels(Y=[], labels=[], xLabel="Class/Label", yLabel="Count", title="Histogram of Trainset"):
    plt.figure()
    plt.clf()

    information = []

    for index in xrange(0, len(Y)):
        y = Y[index]

        unique, counts = np.unique(y, return_counts=True)
        unique_count = np.empty(shape=(unique.shape[0], 2), dtype=np.uint32)

        for x in xrange(0, unique.shape[0]):
            unique_count[x, 0] = unique[x]
            unique_count[x, 1] = counts[x]

        information.append(unique_count)

    n, bins, patches = plt.hist(Y, normed=False, alpha=0.75, label=labels)

    plt.xticks((0.25, 0.75), (0, 1))

    plt.xlabel(xLabel)
    plt.ylabel(yLabel)
    plt.title(title)
    plt.grid(True)
    plt.legend()

现在正在工作,但是,左侧的标签有点出界,我想更好地使酒吧居中......我怎么能这样做？

结果:

Answer 1

我试过了,想出了这个.您可以在代码中更改xticks位置.简单地说,你要做的就是传递一个元组plt.hist,不能更简单吧!所以假设你有两个0和1的列表,所以你要做的是 -

a = np.random.randint(2, size=1000)
b = np.random.randint(2, size=1000)
plt.hist((a, b), 2, label = ("data1", "data2"))
plt.legend()
plt.xticks((0.25, 0.75), (0, 1))

我试图运行的确切代码(在将箱数改为2之后) -

a = np.random.randint(2, size=1000)
b = np.random.randint(2, size=1000)
y = [a, b]
labels = ["data1", "data2"]
generate_histogram_from_array_of_labels(Y = y, labels = labels)

我得到了同样的结果......