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

Question

giacomo labbri 2020-11-12

2
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/646233-n-double-ans-error-using-double-conversion-to-double-from-py-numpy-ndarray-is-not-possible

回答： Michael Loibl 2021-12-7

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]
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