CODEWITHSUNDEEP
matlabfor-loopcell
SH_IQ
SH_IQ

Reputation: 709

How to substract a value from each row in a cell in Matlab?

I have a cell with dimension 41X41 as shown below

enter image description here

that has values equal to 1, it means all its values are equal to ones as shown below:

enter image description here

Based on many values, I could not include it here in one figure, but its dimension is 41 x 41.

What I was trying to do is calculate the number of ones in each row minus one as shown in the snippet of line code below:

ccc = sum(isSmaller{cc,:} == 1)-1

In order to get a cell with 1 row with 40 columns dimension that has 40s. as shown below:

enter image description here

My problem is instead of 40 columns is still showing 41 columns after deleting one from each row as indicated below.

enter image description here

May I get assistance, please? I need it to be 1 row with 40 columns.

Note: I do not care for the first 40 rows or columns or the lasts or the middle ones. I just need it to be done by itself only by minus one. enter image description here After that, I need to sum all the 40s in this ccc = 1x40.

Below is my try:

for cc = 1:length(isSmaller)
    ccc = sum(isSmaller{cc,:} == 1)-1
end

Upvotes: 0

Views: 97

Answers (1)

horchler
horchler

Reputation: 18484

If I understand correctly, isSmaller is a 1-by-1 cell array whose single cell contains a 41-by-41 matrix of logical values all equal to 1 (true):

isSmaller={true(41)};

Then you wish to calculate the sum of each row of this matrix inside of a cell and subtract one from the result:

sum(isSmaller{1},1)-1

But since you only care about the first 40 rows you can trim off the last row with:

sum(isSmaller{1}(:,1:40),1)-1

Or:

sum(isSmaller{1}(:,1:end-1),1)-1

This returns a 1-by-40 matrix where each element is 40.

Finally, you want to sum over the 40 elements of this matrix:

sum(sum(isSmaller{1}(:,1:end-1),1)-1)

This returns 1600, as expected.

No for loops are needed if this is all you need to do and your example is representative. I urge you to read through Matlab's documentation on cell arrays, in particular on how to access data within them.

Upvotes: 2

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