Re: [Matplotlib-users] problems with autoscale_view

On 29/08/10 17:28, Eric Firing wrote:
> On 08/28/2010 06:40 PM, xyz wrote:
>    
>> Hello,
>> If I use autoscale_view than:
>> * plt.text appears outside x and y coordinates
>> * and the coordinates starts do not from 0 whereas I use ax.set_xlim(0)
>> and ax.set_ylim(0)
>>
>> What did I wrong?
>>      
> The call to autoscale_view overrides the earlier calls to set_xlim and
> set_ylim. There is no built-in mechanism for autoscaling only the upper
> limit, and holding the lower limit fixed.  You could make such a
> mechanism by writing a custom Locator, but it may make more sense to
> calculate the upper limit directly in your code based on your data, and
> then use set_xlim and set_ylim to set both ends of each axis.
>
> Eric
>
>    

Thank you for your answer. However, I do not how to calculate the upper 
limit directly from my code based on my data, and then use set_xlim and 
set_ylim to set both ends of each axis. Could you show me please how to 
do it?

Thank you in advance.

from pylab import *
import matplotlib.pyplot as plt

x = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 
20, 21, 22, 23, 24, 25, 26, 27, 28, 29]
y1 = [20, 24, 8, 4, 12, 22, 31, 25, 15, 28, 12, 27, 22, 22, 27, 14, 32, 
28, 8, 17, 2, 8, 29, 13, 14, 20, 11, 28, 8]
y2= [2, 32, 28, 1, 22, 11, 14, 27, 3, 31, 12, 20, 32, 24, 24, 16, 7, 10, 
12, 11, 3, 32, 10, 20, 14, 14, 3, 25, 14]
point_labels1 = ['A=1', 'A=1', 'A=1', 'A=1', 'A=1', 'A=1', 'A=1', 'A=1', 
'A=1', 'A=1', 'A=1', 'A=1', 'A=1', 'A=1', 'A=1', 'A=1', 'A=1', 'A=1', 
'A=1', 'A=1', 'A=1', 'A=1', 'A=1', 'A=1', 'A=1', 'A=1', 'A=1', 'A=1', 'A=1']
point_labels2 = ['B=1', 'B=1', 'B=1', 'B=1', 'B=1', 'B=1', 'B=1', 'B=1', 
'B=1', 'B=1', 'B=1', 'B=1', 'B=1', 'B=1', 'B=1', 'B=1', 'B=1', 'B=1', 
'B=1', 'B=1', 'B=1', 'B=1', 'B=1', 'B=1', 'B=1', 'B=1', 'B=1', 'B=1', 'B=1']

fig = plt.figure()
ax = fig.add_subplot(111)

ax.set_title('The red point should be on the path')

plt.plot(x, y1, 'bo', x, y2, 'go')
ax.grid(True)
ax.set_xlim(0.0)
ax.set_ylim(0.0)

fig.autofmt_xdate()

plt.xticks(range(0, 40, 1))

plt.yticks(range(0, 40, 1))
plt.xlabel('Longitude')
plt.ylabel('Latitude')
plt.legend(('Model length', 'Data length'),
            'best', shadow=True, fancybox=True)

for i, label in enumerate(y1):
   plt.text (x[i], y1[i]+0.2, label,
             horizontalalignment='center' )

for i, label in enumerate(y2):
   plt.text (x[i], y2[i]+0.2, label,
             horizontalalignment='center' )


ax.autoscale_view()
plt.savefig('test.png')
plt.show()