m_power
Reputation: 3204
Creating array of structure from matrix
I have an array of structure similar to this:
AAA(1).Size = rand(1,10);
AAA(2).Size = rand(1,10);
AAA(...).Size = rand(1,10);
...
I have a matrix such as this:
mMatrix = [rand(1,100); rand(1,100); ...]
How can I assign the row values of mMatrix to a new structure in AAA (here called NumberOfElement), in a single call, without having to use a loop?
nRow = size(mMatrix, 1);
for ii = 1:nRow
AAA(ii).NumberOfElement = mMatrix(ii,:);
end
Also, could this be done for multiple matrices and multiple new structures in AAA, such as:
nRow = size(mMatrixDataset1, 1); % The matrices have the same number of rows
for ii = 1:nRow
AAA(ii).NumberOfElementDataset1 = mMatrixDataset1(ii,:);
AAA(ii).NumberOfElementDataset2 = mMatrixDataset2(ii,:);
AAA(ii).NumberOfElementDataset3 = mMatrixDataset3(ii,:);
...
end
Upvotes: 1
Views: 61
Answers (2)
rayryeng
Reputation: 104503
You can split up the matrix mMatrix into multiple cells where each cell would be a row of your matrix. We can do this with mat2cell and then assign to each element in your structure with a single unfolding call. This will work regardless of whether the structure has been declared previously or not. Therefore:
c = mat2cell(mMatrix, ones(size(mMatrix,1),1), size(mMatrix, 2));
[AAA(1:size(mMatrix,1)).NumberOfElement] = c{:};
Example use
%// Set up code
mMatrix = rand(4, 100);
%// Code I wrote above
c = mat2cell(mMatrix, ones(size(mMatrix,1),1), size(mMatrix, 2));
[AAA(1:size(mMatrix,1)).NumberOfElement] = c{:};
AAA =
1x4 struct array with fields:
NumberOfElement
We can go through each structure with a for loop to show what each NumberOfElement field looks like:
for ii = 1 : size(mMatrix, 1)
disp(['Structure ' num2str(ii)]);
disp(['Row ' num2str(ii) ' of matrix']);
disp(mMatrix(ii,:));
disp('Structure contents')
disp(AAA(ii).NumberOfElement);
end
The above code shows you each row of the matrix stored in mMatrix and what the actual field is for each element in your structure.
I get:
Structure 1
Row 1 of matrix
Columns 1 through 8
0.4229 0.6959 0.0688 0.4076 0.5313 0.7788 0.1537 0.4574
Columns 9 through 16
0.6377 0.2891 0.2548 0.3445 0.6022 0.4624 0.3225 0.1759
Columns 17 through 24
0.3411 0.2428 0.1887 0.6834 0.6476 0.2089 0.6073 0.7703
Columns 25 through 32
0.8419 0.5822 0.3181 0.4795 0.5439 0.2187 0.4046 0.6279
Columns 33 through 40
0.1920 0.5254 0.3935 0.3477 0.0445 0.6878 0.6834 0.3309
Columns 41 through 48
0.8217 0.7691 0.3774 0.3276 0.7689 0.5144 0.1999 0.7900
Columns 49 through 56
0.1117 0.1897 0.8507 0.5828 0.0005 0.5277 0.4981 0.7386
Columns 57 through 64
0.0835 0.8908 0.9283 0.8627 0.5523 0.3624 0.1231 0.0427
Columns 65 through 72
0.6952 0.1239 0.2703 0.4170 0.1057 0.5737 0.7378 0.9844
Columns 73 through 80
0.1776 0.9391 0.4671 0.5590 0.0542 0.8985 0.7069 0.4648
Columns 81 through 88
0.1781 0.3358 0.6754 0.7455 0.5972 0.8949 0.4417 0.0934
Columns 89 through 96
0.9954 0.2982 0.6311 0.9051 0.3381 0.0484 0.7297 0.6925
Columns 97 through 100
0.7802 0.1048 0.8905 0.0729
Structure contents
Columns 1 through 8
0.4229 0.6959 0.0688 0.4076 0.5313 0.7788 0.1537 0.4574
Columns 9 through 16
0.6377 0.2891 0.2548 0.3445 0.6022 0.4624 0.3225 0.1759
Columns 17 through 24
0.3411 0.2428 0.1887 0.6834 0.6476 0.2089 0.6073 0.7703
Columns 25 through 32
0.8419 0.5822 0.3181 0.4795 0.5439 0.2187 0.4046 0.6279
Columns 33 through 40
0.1920 0.5254 0.3935 0.3477 0.0445 0.6878 0.6834 0.3309
Columns 41 through 48
0.8217 0.7691 0.3774 0.3276 0.7689 0.5144 0.1999 0.7900
Columns 49 through 56
0.1117 0.1897 0.8507 0.5828 0.0005 0.5277 0.4981 0.7386
Columns 57 through 64
0.0835 0.8908 0.9283 0.8627 0.5523 0.3624 0.1231 0.0427
Columns 65 through 72
0.6952 0.1239 0.2703 0.4170 0.1057 0.5737 0.7378 0.9844
Columns 73 through 80
0.1776 0.9391 0.4671 0.5590 0.0542 0.8985 0.7069 0.4648
Columns 81 through 88
0.1781 0.3358 0.6754 0.7455 0.5972 0.8949 0.4417 0.0934
Columns 89 through 96
0.9954 0.2982 0.6311 0.9051 0.3381 0.0484 0.7297 0.6925
Columns 97 through 100
0.7802 0.1048 0.8905 0.0729
Structure 2
Row 2 of matrix
Columns 1 through 8
0.0942 0.6999 0.3196 0.8200 0.3251 0.4235 0.2810 0.8754
Columns 9 through 16
0.9577 0.6718 0.2240 0.7805 0.3868 0.4243 0.7847 0.7218
Columns 17 through 24
0.6074 0.9174 0.2875 0.5466 0.6790 0.7093 0.4501 0.3502
Columns 25 through 32
0.8329 0.5407 0.1192 0.6393 0.7210 0.1058 0.4484 0.7720
Columns 33 through 40
0.1389 0.5303 0.6714 0.1500 0.7549 0.3592 0.7040 0.4243
Columns 41 through 48
0.4299 0.3968 0.2160 0.6713 0.1673 0.8843 0.4070 0.3185
Columns 49 through 56
0.1363 0.4950 0.5606 0.8154 0.8654 0.4795 0.9009 0.5860
Columns 57 through 64
0.6260 0.9823 0.5801 0.4843 0.6299 0.0495 0.2055 0.6352
Columns 65 through 72
0.4991 0.4904 0.2085 0.2060 0.1420 0.0521 0.0634 0.8589
Columns 73 through 80
0.3986 0.3013 0.6482 0.8541 0.1771 0.1182 0.9995 0.7640
Columns 81 through 88
0.3596 0.1757 0.4685 0.7363 0.2999 0.0715 0.0133 0.3074
Columns 89 through 96
0.3321 0.0464 0.0899 0.5338 0.2940 0.6679 0.7073 0.5567
Columns 97 through 100
0.3376 0.1279 0.7990 0.0885
Structure contents
Columns 1 through 8
0.0942 0.6999 0.3196 0.8200 0.3251 0.4235 0.2810 0.8754
Columns 9 through 16
0.9577 0.6718 0.2240 0.7805 0.3868 0.4243 0.7847 0.7218
Columns 17 through 24
0.6074 0.9174 0.2875 0.5466 0.6790 0.7093 0.4501 0.3502
Columns 25 through 32
0.8329 0.5407 0.1192 0.6393 0.7210 0.1058 0.4484 0.7720
Columns 33 through 40
0.1389 0.5303 0.6714 0.1500 0.7549 0.3592 0.7040 0.4243
Columns 41 through 48
0.4299 0.3968 0.2160 0.6713 0.1673 0.8843 0.4070 0.3185
Columns 49 through 56
0.1363 0.4950 0.5606 0.8154 0.8654 0.4795 0.9009 0.5860
Columns 57 through 64
0.6260 0.9823 0.5801 0.4843 0.6299 0.0495 0.2055 0.6352
Columns 65 through 72
0.4991 0.4904 0.2085 0.2060 0.1420 0.0521 0.0634 0.8589
Columns 73 through 80
0.3986 0.3013 0.6482 0.8541 0.1771 0.1182 0.9995 0.7640
Columns 81 through 88
0.3596 0.1757 0.4685 0.7363 0.2999 0.0715 0.0133 0.3074
Columns 89 through 96
0.3321 0.0464 0.0899 0.5338 0.2940 0.6679 0.7073 0.5567
Columns 97 through 100
0.3376 0.1279 0.7990 0.0885
Structure 3
Row 3 of matrix
Columns 1 through 8
0.5985 0.6385 0.5309 0.7184 0.1056 0.0908 0.4401 0.5181
Columns 9 through 16
0.2407 0.6951 0.6678 0.6753 0.9160 0.4609 0.4714 0.4735
Columns 17 through 24
0.1917 0.2691 0.0911 0.4257 0.6358 0.2362 0.4587 0.6620
Columns 25 through 32
0.2564 0.8699 0.9398 0.5447 0.5225 0.1097 0.3658 0.9329
Columns 33 through 40
0.6963 0.8611 0.7413 0.5861 0.2428 0.7363 0.4423 0.2703
Columns 41 through 48
0.8878 0.8085 0.7904 0.4386 0.8620 0.5880 0.7487 0.5341
Columns 49 through 56
0.6787 0.1476 0.9296 0.8790 0.6126 0.8013 0.5747 0.2467
Columns 57 through 64
0.6609 0.7690 0.0170 0.8449 0.0320 0.4896 0.1465 0.2819
Columns 65 through 72
0.5358 0.8530 0.5650 0.9479 0.1665 0.9312 0.8604 0.7856
Columns 73 through 80
0.1339 0.2955 0.0252 0.3479 0.6628 0.9884 0.2878 0.8182
Columns 81 through 88
0.0567 0.2089 0.9121 0.5619 0.1341 0.2425 0.8972 0.4561
Columns 89 through 96
0.2973 0.5054 0.0809 0.1092 0.7463 0.6035 0.7814 0.3965
Columns 97 through 100
0.6079 0.5495 0.7343 0.7984
Structure contents
Columns 1 through 8
0.5985 0.6385 0.5309 0.7184 0.1056 0.0908 0.4401 0.5181
Columns 9 through 16
0.2407 0.6951 0.6678 0.6753 0.9160 0.4609 0.4714 0.4735
Columns 17 through 24
0.1917 0.2691 0.0911 0.4257 0.6358 0.2362 0.4587 0.6620
Columns 25 through 32
0.2564 0.8699 0.9398 0.5447 0.5225 0.1097 0.3658 0.9329
Columns 33 through 40
0.6963 0.8611 0.7413 0.5861 0.2428 0.7363 0.4423 0.2703
Columns 41 through 48
0.8878 0.8085 0.7904 0.4386 0.8620 0.5880 0.7487 0.5341
Columns 49 through 56
0.6787 0.1476 0.9296 0.8790 0.6126 0.8013 0.5747 0.2467
Columns 57 through 64
0.6609 0.7690 0.0170 0.8449 0.0320 0.4896 0.1465 0.2819
Columns 65 through 72
0.5358 0.8530 0.5650 0.9479 0.1665 0.9312 0.8604 0.7856
Columns 73 through 80
0.1339 0.2955 0.0252 0.3479 0.6628 0.9884 0.2878 0.8182
Columns 81 through 88
0.0567 0.2089 0.9121 0.5619 0.1341 0.2425 0.8972 0.4561
Columns 89 through 96
0.2973 0.5054 0.0809 0.1092 0.7463 0.6035 0.7814 0.3965
Columns 97 through 100
0.6079 0.5495 0.7343 0.7984
Structure 4
Row 4 of matrix
Columns 1 through 8
0.4709 0.0336 0.6544 0.9686 0.6110 0.2665 0.5271 0.9436
Columns 9 through 16
0.6761 0.0680 0.8444 0.0067 0.0012 0.7702 0.0358 0.1527
Columns 17 through 24
0.7384 0.7655 0.5762 0.6444 0.9452 0.1194 0.6619 0.4162
Columns 25 through 32
0.6135 0.2648 0.6456 0.6473 0.9937 0.0636 0.7635 0.9727
Columns 33 through 40
0.0938 0.4849 0.5201 0.2621 0.4424 0.3947 0.0196 0.1971
Columns 41 through 48
0.3912 0.7551 0.9493 0.8335 0.9899 0.1548 0.8256 0.0900
Columns 49 through 56
0.4952 0.0550 0.6967 0.9889 0.9900 0.2278 0.8452 0.6664
Columns 57 through 64
0.7298 0.5814 0.1209 0.2094 0.6147 0.1925 0.1891 0.5386
Columns 65 through 72
0.4452 0.8739 0.6403 0.0821 0.6210 0.7287 0.9344 0.5134
Columns 73 through 80
0.0309 0.3329 0.8422 0.4460 0.3308 0.5400 0.4145 0.1002
Columns 81 through 88
0.5219 0.9052 0.1040 0.1842 0.2126 0.0538 0.1967 0.1017
Columns 89 through 96
0.0620 0.7614 0.7772 0.8258 0.0103 0.5261 0.2880 0.0616
Columns 97 through 100
0.7413 0.4852 0.0513 0.9430
Structure contents
Columns 1 through 8
0.4709 0.0336 0.6544 0.9686 0.6110 0.2665 0.5271 0.9436
Columns 9 through 16
0.6761 0.0680 0.8444 0.0067 0.0012 0.7702 0.0358 0.1527
Columns 17 through 24
0.7384 0.7655 0.5762 0.6444 0.9452 0.1194 0.6619 0.4162
Columns 25 through 32
0.6135 0.2648 0.6456 0.6473 0.9937 0.0636 0.7635 0.9727
Columns 33 through 40
0.0938 0.4849 0.5201 0.2621 0.4424 0.3947 0.0196 0.1971
Columns 41 through 48
0.3912 0.7551 0.9493 0.8335 0.9899 0.1548 0.8256 0.0900
Columns 49 through 56
0.4952 0.0550 0.6967 0.9889 0.9900 0.2278 0.8452 0.6664
Columns 57 through 64
0.7298 0.5814 0.1209 0.2094 0.6147 0.1925 0.1891 0.5386
Columns 65 through 72
0.4452 0.8739 0.6403 0.0821 0.6210 0.7287 0.9344 0.5134
Columns 73 through 80
0.0309 0.3329 0.8422 0.4460 0.3308 0.5400 0.4145 0.1002
Columns 81 through 88
0.5219 0.9052 0.1040 0.1842 0.2126 0.0538 0.1967 0.1017
Columns 89 through 96
0.0620 0.7614 0.7772 0.8258 0.0103 0.5261 0.2880 0.0616
Columns 97 through 100
0.7413 0.4852 0.0513 0.9430
Upvotes: 3
Divakar
Reputation: 221564
This seems to work for the general case of multiple matrices and multiple new structures using cell2struct -
num_matrices = 3; %// Number of matrices to be used
fnames = {'set1','set2','set3'} %// Fieldnames for each matrix
M = cat(1,mat1,mat2,mat3) %// Concatenate all matrices into a single one
%// Form cell array version of the concatenated array and then the struct
C = reshape(mat2cell(M,ones(1,size(M,1)),size(M,2)),size(mat1,1),[])
%// Finally create the struct
AAA = cell2struct(C,fnames,2)
Sample inputs and outputs -
>> mat1
mat1 =
0.2232 0.9404 0.3981 0.6934 0.5052 0.6516 0.1042
0.5832 0.8867 0.2036 0.5595 0.2792 0.4844 0.9474
0.8316 0.0259 0.5718 0.0322 0.4067 0.9513 0.9229
0.3041 0.2078 0.4503 0.4658 0.2488 0.0533 0.8370
>> AAA.set1
ans =
0.2232 0.9404 0.3981 0.6934 0.5052 0.6516 0.1042
ans =
0.5832 0.8867 0.2036 0.5595 0.2792 0.4844 0.9474
ans =
0.8316 0.0259 0.5718 0.0322 0.4067 0.9513 0.9229
ans =
0.3041 0.2078 0.4503 0.4658 0.2488 0.0533 0.8370
>> mat2
mat2 =
0.1468 0.8309 0.3492 0.5820 0.1021 0.4695 0.5848
0.9706 0.2005 0.5406 0.2961 0.3054 0.7118 0.1053
0.4054 0.6320 0.3319 0.9196 0.8603 0.2329 0.7693
0.8479 0.5877 0.8974 0.0810 0.8876 0.0734 0.5933
>> AAA.set2
ans =
0.1468 0.8309 0.3492 0.5820 0.1021 0.4695 0.5848
ans =
0.9706 0.2005 0.5406 0.2961 0.3054 0.7118 0.1053
ans =
0.4054 0.6320 0.3319 0.9196 0.8603 0.2329 0.7693
ans =
0.8479 0.5877 0.8974 0.0810 0.8876 0.0734 0.5933
and so on for other matrices.
Upvotes: 2
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