Assigning values to an array using elements of another array after each element goes through a check
显示 更早的评论
Hello,
Let's say that i have an array (e.g zeros(5,5)).
I'd like to use each element my array has, put each element through an if statement check, make some calculations, and assign that new value to another array that has the same dimensions as my initial one.
If anybody has any idea i'd be of great help!
Thanks!:)
采纳的回答
I think your looking for something like this
start_matrix = rand(5,5); %rand 5x5, values between 0 and 1 (cause whats the point in comparing zeros)
end_matrix = zeros(size(start_matrix)); %same size as starting matrix
for i = 1:size(start_matrix,1)
for j = 1:size(start_matrix,2)
if (start_matrix(i,j) > 0.5)
end_matrix(i,j) = start_matrix(i,j) * 666; %some crazy calculations
else
end_matrix(i,j) = start_matrix(i,j); %no crazy calculations if <= 0.5
end
end
end
end_matrix
更多回答（1 个）
I'd like to use each element my array has, put each element through an if statement check
Just be aware that that's normally the kind of thing you try to avoid in MATLAB. For instance, YT's example is much more efficiently implemented as follows for large matrices,
condition = start_matrix>0.5;
end_matrix=start_matrix;
end_matrix(condition)=start_matrix(condition)*666;
2 个评论
YT
2017-12-14
I agree to what you said, but I think it's useful for beginners to understand how looping through a matrix works.
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