Suppose [1 2 3] [4 5 6] [5 6 7] is a matrix I get as an output in a file. How can I use the matrix as an input to a different code? It seems the matrix output doesn't have the same input structure in Sagemath.
You can try the sage_input function:
sage: m = matrix(QQ, [[1,2,3], [4,5,6], [7,8,9]])
sage: m
[1 2 3]
[4 5 6]
[7 8 9]
sage: sage_input(m)
matrix(QQ, [[1, 2, 3], [4, 5, 6], [7, 8, 9]])
Save the last line to a file instead of just
[1 2 3]
[4 5 6]
[7 8 9]
The sage_input function is documented here
For example, you can parse such matrix printout as
s = '[1 2 3] [4 5 6] [5 6 7]'
M = Matrix(QQ, eval('['+s.replace(' ',',')+']') )
print(M)
Thank you very much. But how should I use it from a file?
load file's content to a string and proceed as above.
For a large matrix (say of order 1000 and elements in range(2^15)), this space can be tricky. For instance, there are non-uniform spaces. Thus it might be a little difficult just to use replace space with a comma to define the matrix. Is there any way [2 4 6] can be treated as a vector [2,4,6] in sage?
It's easy to make spacing uniform by replacing two spaces with one until all such paired spaces are gone.
Thanks. I could able to do the uniformity of spacing using notepad.
Asked: 2021-11-09 00:08:06 +0200
Seen: 395 times
Last updated: Nov 09 '21
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