*邊界框內的文本對齊*

Question

可以使用參數horizontalalignment（ha）和verticalalignment（va）參數（例如，文本框）指定文本框的對齊方式。

import matplotlib.pyplot as plt 
fig, ax = plt.subplots(figsize=(8,5)) 
plt.subplots_adjust(right=0.5) 
txt = "Test:\nthis is some text\ninside a bounding box." 
fig.text(0.7, 0.5, txt, ha='left', va='center') 

主要生產：

反正是有保持相同的包圍盒（bbox）對齊，而改變這種邊界框內文本的對齊方式？例如文本要在邊界框中居中。

（顯然，在這種情況下，我可以只更換邊界框，但在更復雜的情況，我想單獨更改文本的對齊方式。）

Answer 1

確切BBOX取決於特定的後端渲染器。以下示例保留文本bbox的x位置。精確保留x和y有點困難：

import matplotlib 
import matplotlib.pyplot as plt 


def get_bbox(txt): 
    renderer = matplotlib.backend_bases.RendererBase() 
    return txt.get_window_extent(renderer) 

fig, ax = plt.subplots(figsize=(8,5)) 
plt.subplots_adjust(right=0.5) 
txt = "Test:\nthis is some text\ninside a bounding box." 
text_inst = fig.text(0.7, 0.5, txt, ha='left', va='center') 

bbox = get_bbox(text_inst) 
bbox_fig = bbox.transformed(fig.transFigure.inverted()) 
print "original bbox (figure system)\t:", bbox.transformed(fig.transFigure.inverted()) 

# adjust horizontal alignment 
text_inst.set_ha('right') 
bbox_new = get_bbox(text_inst) 
bbox_new_fig = bbox_new.transformed(fig.transFigure.inverted()) 
print "aligned bbox\t\t\t:", bbox_new_fig 

# shift back manually 
offset = bbox_fig.x0 - bbox_new_fig.x0 
text_inst.set_x(bbox_fig.x0 + offset) 
bbox_shifted = get_bbox(text_inst) 
print "shifted bbox\t\t\t:", bbox_shifted.transformed(fig.transFigure.inverted()) 
plt.show()