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将文本放在matplotlib图的左上角

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问题：将文本放在matplotlib图的左上角
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回答 1

问题：将文本放在matplotlib图的左上角

如何在matplotlib图形的左上角（或右上角）放置文本，例如，左上角图例所在的位置，还是绘图的顶部，但在左上角？例如，如果它是一个plt.scatter（），那么将在散点图的平方内放置一些东西，将其放在最左上角。

我想在不理想地知道例如散点图的比例的情况下进行此操作，因为它会随数据集的不同而变化。我只希望它的文字大致在左上方，或大致在右上方。使用图例类型定位时，它无论如何都不应与任何散点图点重叠。

谢谢！

点击查看英文原文

How can I put text in the top left (or top right) corner of a matplotlib figure, e.g. where a top left legend would be, or on top of the plot but in the top left corner? E.g. if it’s a plt.scatter(), then something that would be within the square of the scatter, put in the top left most corner.

I’d like to do this without ideally knowing the scale of the scatterplot being plotted for example, since it will change from dataset to data set. I just want it the text to be roughly in the upper left, or roughly in the upper right. With legend type positioning it should not overlap with any scatter plot points anyway.

thanks!

回答 0

您可以使用text。

text(x, y, s, fontsize=12)

text 可以相对于轴指定坐标，因此文本的位置将与绘图的大小无关：

默认转换指定文本在数据坐标中，或者，您也可以在坐标轴中指定文本（0,0是左下角，而1,1是右上角）。下面的示例将文本放置在轴的中心：：

text(0.5, 0.5,'matplotlib',
     horizontalalignment='center',
     verticalalignment='center',
     transform = ax.transAxes)

要防止文本干扰散点图的任何点，都是比较困难的。比较简单的方法是将y_axis（的ymax ylim((ymin,ymax))轴）设置为比点的最大y坐标高一点的值。这样，您将始终拥有文本的可用空间。

编辑：这里有一个例子：

In [17]: from pylab import figure, text, scatter, show
In [18]: f = figure()
In [19]: ax = f.add_subplot(111)
In [20]: scatter([3,5,2,6,8],[5,3,2,1,5])
Out[20]: <matplotlib.collections.CircleCollection object at 0x0000000007439A90>
In [21]: text(0.1, 0.9,'matplotlib', ha='center', va='center', transform=ax.transAxes)
Out[21]: <matplotlib.text.Text object at 0x0000000007415B38>
In [22]:

ha和va参数设置文本相对于插入点的对齐方式。即。ha =’left’是一个很好的设置，可以防止在手动缩小（变窄）帧时长文本从左轴移出。

点击查看英文原文

You can use text. 

text(x, y, s, fontsize=12)

text coordinates can be given relative to the axis, so the position of your text will be independent of the size of the plot:

The default transform specifies that text is in data coords, alternatively, you can specify text in axis coords (0,0 is lower-left and 1,1 is upper-right). The example below places text in the center of the axes::

text(0.5, 0.5,'matplotlib',
     horizontalalignment='center',
     verticalalignment='center',
     transform = ax.transAxes)

To prevent the text to interfere with any point of your scatter is more difficult afaik. The easier method is to set y_axis (ymax in ylim((ymin,ymax))) to a value a bit higher than the max y-coordinate of your points. In this way you will always have this free space for the text.

EDIT: here you have an example:

In [17]: from pylab import figure, text, scatter, show
In [18]: f = figure()
In [19]: ax = f.add_subplot(111)
In [20]: scatter([3,5,2,6,8],[5,3,2,1,5])
Out[20]: <matplotlib.collections.CircleCollection object at 0x0000000007439A90>
In [21]: text(0.1, 0.9,'matplotlib', ha='center', va='center', transform=ax.transAxes)
Out[21]: <matplotlib.text.Text object at 0x0000000007415B38>
In [22]:

The ha and va parameters set the alignment of your text relative to the insertion point. ie. ha=’left’ is a good set to prevent a long text to go out of the left axis when the frame is reduced (made narrower) manually.

回答 1

一种解决方案是使用该plt.legend功能，即使您不需要实际的图例。您可以使用loc关键字词指定图例框的位置。可以在此网站上找到更多信息，但我还提供了一个示例，说明如何放置图例：

ax.scatter(xa,ya, marker='o', s=20, c="lightgreen", alpha=0.9)
ax.scatter(xb,yb, marker='o', s=20, c="dodgerblue", alpha=0.9)
ax.scatter(xc,yc marker='o', s=20, c="firebrick", alpha=1.0)
ax.scatter(xd,xd,xd, marker='o', s=20, c="goldenrod", alpha=0.9)
line1 = Line2D(range(10), range(10), marker='o', color="goldenrod")
line2 = Line2D(range(10), range(10), marker='o',color="firebrick")
line3 = Line2D(range(10), range(10), marker='o',color="lightgreen")
line4 = Line2D(range(10), range(10), marker='o',color="dodgerblue")
plt.legend((line1,line2,line3, line4),('line1','line2', 'line3', 'line4'),numpoints=1, loc=2)

请注意，因为loc=2，图例位于图的左上角。并且如果文本与图重叠，则可以使用来使其变小legend.fontsize，从而使图例变小。

点击查看英文原文

One solution would be to use the plt.legend function, even if you don’t want an actual legend. You can specify the placement of the legend box by using the loc keyterm. More information can be found at this website but I’ve also included an example showing how to place a legend:

ax.scatter(xa,ya, marker='o', s=20, c="lightgreen", alpha=0.9)
ax.scatter(xb,yb, marker='o', s=20, c="dodgerblue", alpha=0.9)
ax.scatter(xc,yc marker='o', s=20, c="firebrick", alpha=1.0)
ax.scatter(xd,xd,xd, marker='o', s=20, c="goldenrod", alpha=0.9)
line1 = Line2D(range(10), range(10), marker='o', color="goldenrod")
line2 = Line2D(range(10), range(10), marker='o',color="firebrick")
line3 = Line2D(range(10), range(10), marker='o',color="lightgreen")
line4 = Line2D(range(10), range(10), marker='o',color="dodgerblue")
plt.legend((line1,line2,line3, line4),('line1','line2', 'line3', 'line4'),numpoints=1, loc=2)

Note that because loc=2, the legend is in the upper-left corner of the plot. And if the text overlaps with the plot, you can make it smaller by using legend.fontsize, which will then make the legend smaller.