Nate - 3 months ago 31

Python Question

How can I flip the origin of a matplotlib plot to be in the upper-left corner - as opposed to the default lower-left? I'm using matplotlib.pylab.plot to produce the plot (though if there is another plotting routine that is more flexible, please let me know).

I'm looking for the equivalent of the matlab command: axis ij;

Also, I've spent a couple hours surfing matplotlib help and google but haven't come up with an answer. Some info on where I could have looked up the answer would be helpful as well.

Answer

For an image or contour plot, you can use the keyword `origin = None | 'lower' | 'upper'`

and for a line plot, you can set the ylimits high to low.

```
from pylab import *
A = arange(25)/25.
A = A.reshape((5,5))
figure()
imshow(A, interpolation='nearest', origin='lower')
figure()
imshow(A, interpolation='nearest')
d = arange(5)
figure()
plot(d)
ylim(5, 0)
show()
```