Determining aspect ratio when using doublex

Question

How to set aspect ratio for a graph using twinx?

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The following are three examples:

• without twinxto highlight how i set the aspect ratio
• just twinxto illustrate how previously defined aspect ratio reset
• my attempt to define aspect ratio as for y-axis when used twinx(which does not work)

I am using matplotlib 1.3.0
The following script illustrates how I set the aspect ratio of a simple graph:

import numpy as np
import matplotlib.pyplot as plt

x = np.linspace(0,1.6,50) + 50.0

fig = plt.figure()

ax = fig.add_subplot(111)

XLIM = [50.0, 51.6]
YLIM = [0.0, 1.1, 0.0, 11.0] 

ax.plot(x,np.sin(x-50.0),'b')

ax.set_xlim([XLIM[0], XLIM[1]])
ax.set_ylim([YLIM[0], YLIM[1]])

ax.set_xticks(np.arange(XLIM[0], XLIM[1], 0.2))
ax.set_yticks(np.arange(YLIM[0], YLIM[1]+0.1, 0.1)[:-1])

ax.grid(True,which='major',linestyle='solid')

ax.set_aspect((XLIM[1]-XLIM[0])/(YLIM[1]-YLIM[0]))

plt.show()

The picture shown has a certain aspect ratio:

However, if I want to add an extra y-axis using the function twinx(), the aspect ratio is reset:

import numpy as np
import matplotlib.pyplot as plt

x = np.linspace(0,1.6,50) + 50.0

fig = plt.figure()

ax = fig.add_subplot(111)
ax2 = ax.twinx()

XLIM = [50.0, 51.6]
YLIM = [0.0, 1.1, 0.0, 11.0] 

ax.plot(x,np.sin(x-50.0),'b')

ax.set_xlim([XLIM[0], XLIM[1]])
ax.set_ylim([YLIM[0], YLIM[1]])

ax.set_xticks(np.arange(XLIM[0], XLIM[1], 0.2))
ax.set_yticks(np.arange(YLIM[0], YLIM[1]+0.1, 0.1)[:-1])

ax.grid(True,which='major',linestyle='solid')

ax.set_aspect((XLIM[1]-XLIM[0])/(YLIM[1]-YLIM[0]))

plt.show()

( y - reset):

, , :

import numpy as np
import matplotlib.pyplot as plt

x = np.linspace(0,1.6,50) + 50.0

fig = plt.figure()

ax = fig.add_subplot(111)
ax2 = ax.twinx()

XLIM = [50.0, 51.6]
YLIM = [0.0, 1.1, 0.0, 11.0] 

ax.plot(x,np.sin(x-50.0),'b')
ax2.plot(x,np.cos(x-50.0)*10.,'r')

ax.set_xlim([XLIM[0], XLIM[1]])
ax.set_ylim([YLIM[0], YLIM[1]])
ax2.set_ylim([YLIM[2], YLIM[3]])

ax.set_xticks(np.arange(XLIM[0], XLIM[1], 0.2))
ax.set_yticks(np.arange(YLIM[0], YLIM[1]+0.1, 0.1)[:-1])
ax2.set_yticks(np.arange(YLIM[2], YLIM[3]+1.0, 1.0))

ax.grid(True,which='major',linestyle='solid')

ax.set_aspect((XLIM[1]-XLIM[0])/(YLIM[1]-YLIM[0]))
ax2.set_aspect((XLIM[1]-XLIM[0])/(YLIM[3]-YLIM[2]))

plt.show()

:

, , , y - ? twinx?

Answer 1

adjustable . , /.

"box" "datalim", . adjustable='box-forced'.

( , set_foo, . , ax.set_adjustable.):

import numpy as np
import matplotlib.pyplot as plt

x = np.linspace(0,1.6,50) + 50.0

fig, ax = plt.subplots()
ax2 = ax.twinx()

XLIM = [50.0, 51.6]
YLIM = [0.0, 1.1, 0.0, 11.0]

ax.plot(x,np.sin(x-50.0),'b')
ax2.plot(x,np.cos(x-50.0)*10.,'r')

ax.set(adjustable='box-forced',
       xlim=XLIM, ylim=YLIM[:2],
       xticks=np.arange(XLIM[0], XLIM[1], 0.2),
       yticks=np.arange(YLIM[0], YLIM[1]+0.1, 0.1)[:-1],
       aspect=(XLIM[1]-XLIM[0])/(YLIM[1]-YLIM[0]))

ax2.set(adjustable='box-forced',
        ylim=YLIM[2:],
        yticks=np.arange(YLIM[2], YLIM[3]+1.0, 1.0),
        aspect=(XLIM[1]-XLIM[0])/(YLIM[3]-YLIM[2]))

ax.grid(True, which='major',linestyle='solid')

plt.show()