How to indicate legend position in matplotlib in graph coordinates

Question

I am aware of the bbox_to_anchor keyword and this topic, in which it is very useful to indicate how to manually place the legend:

How to derive a legend from the plot

However, I would like to use the coordinates of my x and y axis on the graph to indicate the position of the legend (inside the graph), since I may need to move the figure to a larger figure with another and I do not want to manually play with these coordinates every time I I do. Is it possible?

Edit: small example:

import numpy as n
f, axarr = plt.subplots(2,sharex=True)
axarr[1].set_ylim([0.611,0.675])
axarr[0].set_ylim([0.792,0.856]) 
axarr[0].plot([0, 0.04, 0.08],n.array([ 0.83333333,  0.82250521,0.81109048]), label='test1') 
axarr[0].errorbar([0, 0.04, 0.08],n.array([ 0.8,  0.83,   0.82]),n.array([0.1,0.1,0.01]), label='test2') 
axarr[1].plot([0, 0.04, 0.08],n.array([ 0.66666667,  0.64888304,  0.63042428]))
axarr[1].errorbar([0, 0.04, 0.08],n.array([ 0.67,  0.64,  0.62]),n.array([ 0.01,  0.05,  0.1]))
axarr[0].legend(bbox_to_anchor=(0.04, 0.82, 1., .102),labelspacing=0.1,       handlelength=0.1, handletextpad=0.1,frameon=False, ncol=4, columnspacing=0.7)

, , 0,82, ( 5 ) bbox_to_anchor = (0.04, 1.15, 1.,.102), (0,02, 0,83). , , - ?

Answer 1

loc , . loc loc="best", bbox_to_anchor.
bbox_to_anchor, loc.

bbox_to_anchor (0,0,1,1), . , , (x0, y0) .

, ​​ (0.6,0.5) ( ) loc. , loc " , bbox_to_anchor 2- ".

import matplotlib.pyplot as plt
plt.rcParams["figure.figsize"] = 6, 3
fig, axes = plt.subplots(ncols=3)
locs = ["upper left", "lower left", "center right"]
for l, ax in zip(locs, axes.flatten()):
    ax.set_title(l)
    ax.plot([1,2,3],[2,3,1], "b-", label="blue")
    ax.plot([1,2,3],[1,2,1], "r-", label="red")
    ax.legend(loc=l, bbox_to_anchor=(0.6,0.5))
    ax.scatter((0.6),(0.5), s=81, c="limegreen", transform=ax.transAxes)

plt.tight_layout()    
plt.show()

. 4- 'bbox_to_anchor' matplotlib?.

---

, , , bbox_transform.

ax.legend(bbox_to_anchor=(1,0), loc="lower right",  bbox_transform=fig.transFigure)

, , , bbox_transform=ax.transData.

Answer 2

loc. https://matplotlib.org/api/pyplot_api.html#matplotlib.pyplot.legend

import matplotlib.pyplot as plt

plt.subplot(211)
plt.plot([1,2,3], label="test1")
plt.plot([3,2,1], label="test2")
# Place a legend above this subplot, expanding itself to
# fully use the given bounding box.
plt.legend(bbox_to_anchor=(0., 1.02, 1., .102), loc=3,
           ncol=2, mode="expand", borderaxespad=0.)

plt.subplot(223)
plt.plot([1,2,3], label="test1")
plt.plot([3,2,1], label="test2")
# Place a legend to the right of this smaller subplot.
plt.legend(bbox_to_anchor=(1.05, 1), loc=2, borderaxespad=0.)

plt.show()