Comparing Matrices in a Struct

2 次查看（过去 30 天）
Chris Dan
Chris Dan 2019-10-27
编辑： per isakson 2019-11-10
Hello Guys, I am new to MATLAB, I have some matrices in a struct more like an array of arrays.
I want to compare their sizes and see if they are equal or not.
and how to make them equal to the biggest matrice, maybe by adding zeros to the smaller matrices.
I am attaching a picture

请先登录，再回答此问题。

采纳的回答

per isakson
per isakson 2019-10-28
编辑：per isakson 2019-11-8
Try this
S(1).model_data = rand( 4, 10 );
S(2).model_data = rand( 2, 10 );
S(3).model_data = rand( 3, 11 );
Out = cssm_( S );
function Out = cssm_( S )
sz(1) = max( arrayfun( @(s) size( s.model_data, 1 ), S ) );
sz(2) = max( arrayfun( @(s) size( s.model_data, 2 ), S ) );
Out = struct( 'model_data', repmat( {nan(sz)}, 1,numel(S) ) );
for jj = 1 : numel(S)
sz = size(S(jj).model_data);
Out(jj).model_data(1:sz(1),1:sz(2)) = S(jj).model_data;
end
end
In response to comment
This will handle sparse, test it. ( cssm_ assumes that all values of data_model are either full or sparse.)
S(1).model_data = sparse( rand( 4, 10 ) );
S(2).model_data = sparse( rand( 2, 10 ) );
S(3).model_data = sparse( rand( 3, 11 ) );
Out = cssm_( S );
function Out = cssm_( S )
sz(1) = max( arrayfun( @(s) size( s.model_data, 1 ), S ) );
sz(2) = max( arrayfun( @(s) size( s.model_data, 2 ), S ) );
if issparse( S(1).model_data )
Out = struct( 'model_data', repmat( {sparse(nan(sz))}, 1,numel(S) ) );
else
Out = struct( 'model_data', repmat( {nan(sz)}, 1,numel(S) ) );
end
for jj = 1 : numel(S)
sz = size(S(jj).model_data);
Out(jj).model_data(1:sz(1),1:sz(2)) = S(jj).model_data;
end
end
Version 3 in response to a later comment
S(1,1).model_data = sparse( rand( 4, 3 ) );
S(1,2).model_data = sparse( rand( 2, 3 ) );
S(1,3).model_data = sparse( rand( 3, 5 ) );
Out = cssm_( S );
function Out = cssm_( S )
sz(1) = max( arrayfun( @(s) size( s.model_data, 1 ), S ) );
sz(2) = max( arrayfun( @(s) size( s.model_data, 2 ), S ) );
if issparse( S(1).model_data )
Out = struct( 'model_data', repmat( {sparse(nan(sz))}, size(S) ) );
else
Out = struct( 'model_data', repmat( {nan(sz)}, size(S) ) );
end
for jj = 1 : numel(S)
sz = size(S(jj).model_data);
Out(jj).model_data(1:sz(1),1:sz(2)) = S(jj).model_data;
end
end
  8 个评论
显示 6更早的评论
Chris Dan
Chris Dan 2019-11-10
编辑：per isakson 2019-11-10
per isakson
Hey, Thanks again for you help!! :) :)
I just have one more question, it is a different problem but is related matrix addition.
I am copying my code, the thing is I have the logic developed somehow, but it is not giving me correct answers.
B = [ 1 -1 1;
-1 1 1;
1 -1 1];
C = [ 1 -1 2;
-1 1 2;
4 5 5];
D = [ 1 -1 1;
-1 1 4;
5 6 7];
T = zeros(7,7)
d=zeros(3,3,3);
d(:,:,1) = B;
d(:,:,2) = C;
d(:,:,3) = D;
for k = 1:1:3
for i = 1:1:3
for j = 1:1:3
T((i+k)-1,(j+k)-1) = T((i+k)-1,(j+k)-1) + d(i,j,k)
end
end
end
The answer which I am getting is this : which is wrong
What should I get is
T = [ 1 -1 1 0 0 0 0
-1 1 1 0 0 0 0
1 -1 2 -1 2 0 0
0 0 -1 1 2 0 0
0 0 4 5 6 -1 1
0 0 0 0 -1 1 4
0 0 0 0 5 6 7]
If it is possible, can you help me and tell me what mistake I am making, that would be very nice :)
per isakson
per isakson 2019-11-10
编辑：per isakson 2019-11-10
It's far from obvious to me what algorithm you try to implement and I cannot easily deduce it from the example.
Regarding your code I directly observe that
  • all T_actual(6:7,:) and all T_actual(:,6:7) are equal to zero
  • the maximum values of the counters, k, i, j, are 3
  • the maximum value of (i+k)-1 and (j+k)-1, respectively is 5, which explains why all T_actual(6:7,:) and all T_actual(:,6:7) are equal to zero
  • all T_actual(5,1:5)==T_expected(7,3:7)
Proposal: Post a new question in which you describe in some detail the algorithm you try to implement.

请先登录，再进行评论。

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Structures 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by