Pad empty spaces in matrix with 0

I have a matrix of the form:
1 4 6 3 7 3
4 6 2 9
5 5 8 2 5
4 8 1 3 9 4
As I accumulated the rows of the matrix from different sources there is a inconsistency in the length of rows. How do I pad the empty spaces with 0? Please help.

3 Comments

Are these rows each in a cell? What is your exact data structure?
Meg Cullen
Meg Cullen on 12 May 2019
Edited: Meg Cullen on 12 May 2019
a = [c1m_wrf(:,3)';c2m_wrf(:,3)';c3m_wrf(:,3)';c4m_wrf(:,3)'];
I created a matrix but since the columns of the different cells are of different length...its not working
What are the "empty spaces" - do you want to just pad the right hand side?

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 Accepted Answer

Try this:
c1m_wrf = [1 4 6 3 7 3 ]
c2m_wrf = [4 6 2 9]
c3m_wrf = [5 5 8 2 5]
c4m_wrf = [4 8 1 3 9 4 ]
maxLength = max([length(c1m_wrf), length(c2m_wrf), length(c3m_wrf), length(c4m_wrf)])
ca = {c1m_wrf, c2m_wrf, c3m_wrf, c4m_wrf}
m = zeros(4, maxLength);
for row = 1 : length(ca)
thisVector = ca{row};
thisLength = length(thisVector);
m(row, 1:thisLength) = thisVector;
end
You get
m =
1 4 6 3 7 3
4 6 2 9 0 0
5 5 8 2 5 0
4 8 1 3 9 4

More Answers (1)

C={[1 4 6 3 7 3] ;...
[4 6 2 9] ;...
[5 5 8 2 5] ;...
[4 8 1 3 9 4] };
M=max(cellfun('prodofsize',C));
Wanted = cell2mat(cellfun(@(x) [x zeros(1,M-numel(x))],C,'un',0))

2 Comments

It is unfortunate the pad function (R2016b and later) requires a cellstr input:
%doesn't work:
Wanted = cell2mat(pad(C,'right',0));
%does work:
Wanted = double(cell2mat(pad(cellfun(@char,C,'un',0),'right',char(0))));
I have the feeling Matlab is getting a bit less weakly typed than it used to be.
Wow ,didn’t know that function so +1 .

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