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How to plot the output of A.eigenvectors_right()?

asked 2014-09-08 06:06:34 +0200

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Trying to calculate and plot eigenvectors of a matrix A. The call A.eigenvectors_right() works, but the output is a mixed list. How to extract the eigenvectors from it to plot them? The attempt: s=Lambda.eigenvectors_right();v=s[1];v[1];v1=v[1];plot(v1) gives an error message... Thank you.

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answered 2014-09-08 09:22:59 +0200

FrédéricC gravatar image

updated 2014-09-08 09:23:50 +0200

Something like that maybe ?

sage: A = matrix([[2, 3], [3, 5]])
sage: l = flatten([u[1] for u in A.eigenvectors_right()])
sage: add(plot(v) for v in l)
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It works!...

DVD gravatar imageDVD ( 2014-09-08 21:46:20 +0200 )edit

answered 2014-09-08 10:57:01 +0200

tmonteil gravatar image

As you can see, v1 is a list containing a single tuple:

sage: v1
[(1, 1.618033988749895?)]

You want to plot the vector described by the inner tuple, not the list. The following should work:

sage: plot(v1[0])
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Looks like "flatten()" is needed (see below)...

DVD gravatar imageDVD ( 2014-09-08 21:44:47 +0200 )edit

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Asked: 2014-09-08 06:06:34 +0200

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Last updated: Sep 08 '14