Replacing a cell array column with another cell array column (conversion to cell from double is not possible)
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Background:
A is a 1x51 cell - containing 51 Mx6 cells.
Snippet:
B is a 1x51 cell - containing 51 Mx1 doubles.
Snippet:
I want to remove columns 4 and 5 from all 51 cells of A and replace them with the column vectors located in B. So in A{1,1}(:,4:5) is replaced with B{1,1} (B being a cell of column vectors), in A{1,2}{:,4:5} is replaced with B{1,2}.
Since B is doubles and A is cells I can't simply do this:
A{1,1}(:,4) = B{1,1};
A{1,1}(:,5) = [];
Conversion to cell from double is not possible.
>>>>>
Error in IMPORT (line 129)
A{1,1}(:,4)=B{1,1};
So my question is: how do I go about replacing those columns and then how do I loop it through the whole of A to replace each cell's columns? (I'm assuming this can be done using something like cellfun?)
Thanks in advance.
采纳的回答
Image Analyst
2014-11-27
Let's look at what
A{1,1}(:,4) = B{1,1};
actually is. A{1,1} is taking the upper left cell in the 1 by 51 cell array, in other words the first cell since it's a row vector. Since you used braces, you're extracting the cell contents rather than referring to the cell itself. But the cell contents is yet another cell array! It's a cell array of 111 rows of cells by 6 columns of cells. So when you say A{1,1}(:,4), you're taking all the rows in column 4 of that 6 column cell array. So now you have a column vector of cells that is 111 cells tall. Inside each of those 111 cells is a double array, but the expression itself is a column of cells, not doubles , and therein lies the problem.
Now, let's look at B{1,1}. You're using braces so you're extracting the contents of the upper left cell of the B cell array. The contents of that cell is a 111 by 1 column vector of doubles.
Knowing this, and after reading the FAQ, take another crack at it.
2 个评论
Stephen
2014-11-27
I was actually reluctant to post a question having done a fair amount of digging around prior to doing so, I've previously read through the FAQ. If you look at the data within A and B (show below) you'll understand where my confusion is coming from.
Here is a snippet of column 4 and 5 from A{1,1}
Here is a snippet from B{1,1}
Reiteration of my original question, simply imagine that the data from A{1,1} in column 4 and 5 was replaced with the data in B{1,1}. The frustration is simply not knowing how to write it.
Image Analyst
2014-11-27
If Guillaume's solution doesn't do it, then please attach a mat file so we can try some things.
更多回答（1 个）
Guillaume
2014-11-27
As Image Analyst said, you're trying to replace cells with a matrix, so first you need to convert that matrix into cells:
A = {cell(111,6), cell(50,6), cell(53,6), cell(74,6), cell(120,6)};
B = {rand(111,1), rand(50,1), rand(53,1), rand(74,1), rand(120,6)};
for col = 1:numel(A)
A{col}(:, 4) = num2cell(B{col});
A{col}(:, 5) = [];
end
4 个评论
Stephen
2014-11-28
The A and B construction is just there for generating some demonstration data.
The rest of the code makes no assumption on the size of the cell arrays, other than the matrices in B are column vectors with the same numbers of rows as the respective cell arrays in A.
The code is already fully automated.
Stephen
2014-11-28
Guillaume
2014-11-28
The best way for thanking people is to accept their answer.
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