n=double(ans) Error using double Conversion to double from py.numpy.ndarray is not possible.

Hi,

I am calling a python function from matlab and I get back a ndarray. I try to convert it to a matlab array using double() but i get an error even if I have Matlab 2018b

n=double(ans)

where ans is my ndarray. I get this error:

"Error using double

Conversion to double from py.numpy.ndarray is not possible."

Any idea why it doesn't work or if there is an alternative way to convert ndarray in matlab array?

Thansk in advance,

Giacomo

For reference the output of details(ans) is this:

py.numpy.ndarray handle with properties:

           T: [1×1 py.numpy.ndarray]
        base: [1×1 py.NoneType]
      ctypes: [1×1 py.numpy.core._internal._ctypes]
        data: [1×1 py.memoryview]
       dtype: [1×1 py.numpy.dtype]
       flags: [1×1 py.numpy.flagsobj]
        flat: [1×1 py.numpy.flatiter]
        imag: [1×1 py.numpy.ndarray]
    itemsize: [1×1 py.int]
      nbytes: [1×1 py.int]
        ndim: [1×1 py.int]
        real: [1×1 py.numpy.ndarray]
       shape: [1×1 py.tuple]
        size: [1×1 py.int]
     strides: [1×1 py.tuple]

  Methods, Events, Superclasses

[meng yuan]

Have you solved it? I met the same problem with you.

Answer 1

[Michael Loibl]

I just answered a similar question here. It is a general solution, but it might help some people.