Unable to access all data in a Python DataArray

I have imported a Python DataArray into Matlab but I can't work out how to access all the data in the DataArray. My 1x1 DataArray is called st and when I run

>> st.size

ans =

Python int with properties:

denominator: [1×1 py.int]

imag: [1×1 py.int]

numerator: [1×1 py.int]

real: [1×1 py.int]

2038

So it says the size is 2038, which is as expected, but when I try to access the data (a row of alternating 'opened' 'closed' 'opened' ....), I only get a shortened version of the data. I want to get a full row of 2038 states (opened or closed; here I could of course generate that list myself but it is not always this predictable)

>> st.data.char

ans =

'['closed' 'opened' 'closed' ... 'opened' 'closed' 'opened']'

When I run

>> st.data

ans =

Python ndarray with properties:

T: [1×1 py.numpy.ndarray]

base: [1×1 py.numpy.ndarray]

ctypes: [1×1 py.numpy.core._internal._ctypes]

data: [1×2038 py.memoryview]

dtype: [1×1 py.numpy.dtype[object_]]

flags: [1×1 py.numpy.core.multiarray.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]

['closed' 'opened' 'closed' ... 'opened' 'closed' 'opened']

I am hoping it is an easy problem to solve and that its just due to my very limited knowledge of Python.

Any help much appreciated

Jos

Answer 1

[Gayatri Rathod]

Hi Joseph,

Based on the information you provided, it seems like you have imported a Python DataArray into MATLAB.

To access the full row of 2038 states (alternating 'opened' and 'closed'), you can try the following approach:

1. Access the “st.data” property, which gives you a Python “ndarray" object.

2. Convert the Python “ndarray” object to a MATLAB cell array using the “cellstr" function.

Example code snippet:

% Convert the Python ndarray to a MATLAB cell array
dataCellArray = cellstr(st.data);

% Access the full row of states
fullRow = dataCellArray{1};

% Display the full row
disp(fullRow); 

The “cellstr" function converts each element of the Python ndarray to a cell array element. Then by accessing “dataCellArray{1}", you retrieve the first element of the cell array which corresponds to the full row of states.

You can read more about the “cellstr" function from the following documentation: cellstr function

Hope it helps!

[Joseph van 't Hoff]

thanks for your answer, in my case this does not work though, maybe because my ndarray is a numpy ndarray. When I run cellstr on it it gives

Error using cellstr

Conversion to cellstr from py.numpy.ndarray is not possible.

I found out how to convert it though, by using string(st.data.tolist) I get an array of strings with each cell containing 'opened' or 'closed'