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How to access elements in numpy.array without converting the array?

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Hello all,
I'm using an outofprocess python enviornment and would like to access individual or a set of elements in a numpy array without converting it. For example.
NP = py.importlib.import_module('numpy');
x = NP.array([1 3 5 7 9 11]);
now I would like to change x(2) to 0, this is what I do now and is clearly not efficient for very large arrays in a for loop for example.
tmp = double(x);
tmp(2) = 0;
x = NP.array(tmp);
my ultimate goal is to be able to take change a set of elements eg. 3:4, or 2:2:6
Thank you for your help

Accepted Answer

Al Danial
Al Danial on 3 Nov 2023
Use NumPy's put() function:
>> NP = py.importlib.import_module('numpy');
>> x = NP.array([1 3 5 7 9 11]);
>> ind = int64([0 2]); % indices to 1st and 3rd elements
>> newvals = [-11 -55]; % new values for 1st and 3rd elements
>> NP.put(x, ind, newvals);
>> x
x =
Python ndarray:
-11 3 -55 7 9 11
Use details function to view the properties of the Python object.
Use double function to convert to a MATLAB array.

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