Question

I'm plotting a cross-tabulation of various offices within certain categories. I'd like to put together a horizontal stacked bar chart where each office and its value is labeled.

Here's some example code:

df = pd.DataFrame({'office1': pd.Series([1,np.nan,np.nan], index=['catA', 'catB', 'catC']),
              'office2': pd.Series([np.nan,8,np.nan], index=['catA', 'catB', 'catC']),
              'office3': pd.Series([12,np.nan,np.nan], index=['catA', 'catB', 'catC']),
              'office4': pd.Series([np.nan,np.nan,3], index=['catA', 'catB', 'catC']),
              'office5': pd.Series([np.nan,5,np.nan], index=['catA', 'catB', 'catC']),
              'office6': pd.Series([np.nan,np.nan,7], index=['catA', 'catB', 'catC']),
              'office7': pd.Series([3,np.nan,np.nan], index=['catA', 'catB', 'catC']),
              'office8': pd.Series([np.nan,np.nan,11], index=['catA', 'catB', 'catC']),
              'office9': pd.Series([np.nan,6,np.nan], index=['catA', 'catB', 'catC']),
              })
ax = df.plot.barh(title="Office Breakdown by Category", legend=False, figsize=(10,7), stacked=True)

This gives me a fine starting point:

However, what I'd like to have is this:

After some research, I came up with the following code that correctly lines up labels on the 'category' axis:

def annotateBars(row, ax=ax):
    for col in row.index:
        value = row[col]
        if (str(value) != 'nan'):
            ax.text(value/2, labeltonum(row.name), col+","+str(value))

def labeltonum(label):
    if label == 'catA':
        return 0
    elif label == 'catB':
        return 1
    elif label == 'catC':
        return 2

df.apply(annotateBars, ax=ax, axis=1)

But this doesn't factor in the "stacking" of the bars. I've also tried iterating through the patches container returned by the plot command (which can let me retrieve x & y positions of each rectangle), but I then lose any connection to the office labels.

Answer 1

想出来。如果我遍历数据帧的每一行的列，我可以构建一个我需要的标签列表，它匹配ax.patches中矩形的进展。解决方案如下：

labels = []
for j in df.columns:
    for i in df.index:
        label = str(j)+": " + str(df.loc[i][j])
        labels.append(label)

patches = ax.patches

for label, rect in zip(labels, patches):
    width = rect.get_width()
    if width > 0:
        x = rect.get_x()
        y = rect.get_y()
        height = rect.get_height()
        ax.text(x + width/2., y + height/2., label, ha='center', va='center')

当添加到上面的代码中时，产生：

现在只处理重新安排太小的酒吧标签......

Answer 2

您也可以将函数annotateBars()更改为：

def annotateBars(row, ax=ax):
    curr_value = 0 
    for col in row.index:
        value = row[col]
        if (str(value) != 'nan'):
            ax.text(curr_value + (value)/2, labeltonum(row.name), col+","+str(value), ha='center',va='center')
            curr_value += value

Adding labels to stacked bar chart

2 个答案: