Numpy Matrix keeps giving me an Error,

Question:

Okay this is werid, i keep getting the error, randomly.

ValueError: matrix must be 2-dimensional

So i tracked it down, and cornered it to basically something like this:

a_list = [[(1,100) for _ in range(32)] for _ in range(32)]
numpy.matrix(a_list)

Whats wrong with this? If i print a_list it is clearly a 2d matrix of tuples, however numpy does not believe so.

Asked By: UberJumper

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Answers:

tuples have more than one value, so they are considered a dimension. So you’re creating a 3d matrix.

Answered By: nosklo

What are you trying to do? In numpy, a matrix is a 2-d array of numbers.

You can make a 32x32x2 “matrix” with numpy.array(a_list).
You could also make a 32×32 array of tuples using numpy object arrays, but there is little that would be better for than the 32x32x2 case (since you can think of it as a 32×32 array of 2-element arrays).

Answered By: Andrew Jaffe

The easiest way around this is to just use a numpy array, instead of a numpy matrix:

a_list = [[(1,100) for _ in range(32)] for _ in range(32)]
arr=numpy.array(a_list)

Numpy matrices are strictly 2-dimensional, and a_list is 3-dimensional. So numpy matrices are not an option.

Answered By: unutbu
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