Question :
I am using numpy. I have a matrix with 1 column and N rows and I want to get an array from with N elements.
For example, if i have M = matrix([[1], [2], [3], [4]]), I want to get A = array([1,2,3,4]).
To achieve it, I use A = np.array(M.T)[0]. Does anyone know a more elegant way to get the same result?
Thanks!
Answer #1:
If you’d like something a bit more readable, you can do this:
A = np.squeeze(np.asarray(M))
Equivalently, you could also do: A = np.asarray(M).reshape(-1), but that’s a bit less easy to read.
Answer #2:
result = M.A1
https://docs.scipy.org/doc/numpy-1.14.0/reference/generated/numpy.matrix.A1.html
matrix.A1
1-d base array
Answer #3:
A, = np.array(M.T)
depends what you mean by elegance i suppose but thats what i would do
Answer #4:
You can try the following variant:
result=np.array(M).flatten()
Answer #5:
np.array(M).ravel()
If you care for speed; But if you care for memory:
np.asarray(M).ravel()
Answer #6:
Or you could try to avoid some temps with
A = M.view(np.ndarray)
A.shape = -1
Answer #7:
First, Mv = numpy.asarray(M.T), which gives you a 4×1 but 2D array.
Then, perform A = Mv[0,:], which gives you what you want. You could put them together, as numpy.asarray(M.T)[0,:].
Answer #8:
This will convert the matrix into array
A = np.ravel(M).T
