MATLAB: Is there any instruction can ignore the “0” value and find the minimum value of a matrix

MATLAB

Is there any instruction can ignore the "0" value and find the minimum value of a matrix ? I mean ,if i assume

A=[0 1 2 3]

How do i write the code to let the minimum value is 1 instead of 0

Best Answer

A=[0 1 2 3]
[val,idx] = sort(A) ;
iwant = val(2)
A(A==0) = NaN
min(A)

Related Solutions

MATLAB: Save instruction

You would rather do well to save the data in a vector than write a mat file every time the loop runs:

This video should help:

http://blogs.mathworks.com/videos/2007/08/20/matlab-basics-video/

You can save the output in a vector or matrix as shown,

Eg:

for i=1:10
y(i)=i+rand;  % use y(i) so that it is written as a vector
end

or you could use:

z=[];
for i=1:10
z=[z i+rand];
end

MATLAB: Find the rth “0” in specific columns in a matrix

cols = [1 3 4 6 7]; % selected columns.

num_zeros = [3,4];% The ordinal number "0" in each selected column.

M_nozeros = cumsum(~M).*~M;
[~,ii] = ismember(M_nozeros(:,cols),num_zeros);
[k,jj] = ndgrid(1:size(M,1),cols);
idx = [k(:),jj(:)];
out = accumarray(ii(:) + 1,1:numel(ii),[],@(x){idx(x,:)});
out = out(2:end);

out - cell array, here each cell corresponds to the ordinal number "0" ( num_zeros), each cell contains a double matrix: rows are the ordinal number of the row containing zero, the columns correspond to cols.

Use:

>> cols = [1 3 4 6 7]; % selected columns.
num_zeros = [3,4];% The ordinal number "0" in each selected column.
M = rand(15,10) < .25
M =
  15×10 logical array
   0   0   0   0   1   0   0   0   0   0
   0   0   0   0   0   0   1   0   0   1
   1   0   0   1   1   0   0   0   0   1
   0   0   0   1   0   0   1   0   0   0
   0   0   0   0   1   0   0   0   0   0
   0   0   0   1   1   0   0   0   0   0
   0   1   0   0   0   1   0   0   0   0
   0   1   0   0   0   0   0   0   1   1
   1   0   1   0   0   1   0   0   0   0
   0   0   0   0   0   0   0   0   0   0
   1   0   0   0   0   0   1   0   0   0
   0   0   0   1   1   1   1   1   0   1
   0   0   0   0   0   0   1   0   0   0
   0   0   1   0   0   1   1   0   0   0
   1   0   0   0   0   0   1   0   0   0
>> 
>> M_nozeros = cumsum(~M).*~M;
[~,ii] = ismember(M_nozeros(:,cols),num_zeros);
[k,jj] = ndgrid(1:size(M,1),cols);
idx = [k(:),jj(:)];
out = accumarray(ii(:) + 1,1:numel(ii),[],@(x){idx(x,:)});
out = out(2:end);
>> 
>> out{:}
ans =
     4     1
     3     3
     3     6
     5     4
     5     7
ans =
     4     6
     5     1
     6     7
     4     3
     7     4
>>

Best Answer

Related Solutions

MATLAB: Save instruction

MATLAB: Find the rth “0” in specific columns in a matrix

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