Removing zeros from matrix

Hi,

Been trying to remove these zeros using NaN and find etc. but to no avail.

Trying to remove zeros so that I can pull out the end (non-zero) values from each row and put into a new n:1 matrix. If there is also a way of doing this without nessisarily having to remove the zeros then that would be fine also.

Example matrix (mine is a lot larger but follows similar format with zeros being at the end of the rows):

A = [1 2 3 4 5 6; 1 2 3 4 5 6; 1 2 3 4 5 0; 1 2 3 4 0 0; 1 2 3 0 0 0]

Thanks in advance.

Edit:

The final desired output would be:

B = [6; 6; 5; 4; 3]

Answer 1

[Stephen23]

A = [1,2,3,4,5,6;1,2,3,4,5,6;1,2,3,4,5,0;1,2,3,4,0,0;1,2,3,0,0,0]

A = 5×6

1 2 3 4 5 6 1 2 3 4 5 6 1 2 3 4 5 0 1 2 3 4 0 0 1 2 3 0 0 0

Method one: NONZEROS and CELLFUN

baz = @(v)v(end);
fnh = @(v)baz(nonzeros(v));
B = cellfun(fnh,num2cell(A,2))

B = 5×1

6 6 5 4 3

Method two: ROT90 and CUMSUM and logical indexing

tmp = rot90(A);
idx = tmp~=0;
idx = idx & cumsum(idx,1)==1;
B = tmp(idx)

B = 5×1

6 6 5 4 3

Method 3: FIND and CELLFUN

foo = @(v)v(find(v,1,'last'));
B = cellfun(foo,num2cell(A,2))

B = 5×1

6 6 5 4 3

Method 4: MAX and SUB2IND and linear indexing:

sza = size(A);
idc = max((A~=0).*(1:sza(2)),[],2);
idr = 1:sza(1);
B = A(sub2ind(sza,idr(:),idc))

B = 5×1

6 6 5 4 3

Answer 2

[Alan Stevens]

Like this?

A = [1 2 3 4 5 6; 1 2 3 4 5 6; 1 2 3 4 5 0; 1 2 3 4 0 0; 1 2 3 0 0 0];
B = A'; B=B(:);
B(B==0)=[]

B = 24×1

1 2 3 4 5 6 1 2 3 4

[Robert Bridges]

No, I would like it to keep the same sort of format but just remove the trailing zeros:

B = [1 2 3 4 5 6; 1 2 3 4 5 6; 1 2 3 4 5; 1 2 3 4; 1 2 3]

[Stephen23]

Every row must have the same number of elements, so this is not a valid matrix:

B = [1 2 3 4 5 6; 1 2 3 4 5 6; 1 2 3 4 5; 1 2 3 4; 1 2 3]

Error using vertcat
Dimensions of arrays being concatenated are not consistent.

Would you like to replace the zeros with NaNs instead?

[Robert Bridges]

Yes, NaNs would work as long as afer this I can take the final real value from each row and input this into a new matix.

I've edited the question to include the final matrix B.

Answer 3

[Jan]

What is the wanted output?

A = [1 2 3 4 5 6; 1 2 3 4 5 6; 1 2 3 4 5 0; 1 2 3 4 0 0; 1 2 3 0 0 0];

B1 = A;
B1(B1 == 0) = NaN

B1 = 5×6

1 2 3 4 5 6 1 2 3 4 5 6 1 2 3 4 5 NaN 1 2 3 4 NaN NaN 1 2 3 NaN NaN NaN

B2 = A(A~=0)

B2 = 24×1

1 1 1 1 1 2 2 2 2 2

I'm not sure what this means: "pull out the end (non-zero) values from each row and put into a new n:1 matrix"

Maybe:

B = cell(height(A), 1);
for k = 1:height(A)
   B{k} = A(k, A(k, :) ~= 0);
end

[Robert Bridges]

The final wanted output would be:

B = [6; 6; 5; 4; 3]

Using NaN's to get to this or other means isn't a problem

Edited in Question now.