sum of series of matrix

1 Ansicht (letzte 30 Tage)
rakesh kumar
rakesh kumar am 16 Aug. 2022
Kommentiert: Image Analyst am 16 Aug. 2022
I have a series of matrices like A1, A2,.........A99. I want to find sum of three matrices like(A1+A2+A3) then (A4+A5+A6)........(A97+A98+A99)
  2 Kommentare
Chunru
Chunru am 16 Aug. 2022
Can you put your matrices into a single 3D array like A(i,j,k)?
rakesh kumar
rakesh kumar am 16 Aug. 2022
yes, but my problem is that have to find the sum in groups as I have mentioned. Thanks in advance for your help.

Melden Sie sich an, um zu kommentieren.

Melden Sie sich an, um diese Frage zu beantworten.

Akzeptierte Antwort

Chunru
Chunru am 16 Aug. 2022
Ran in:
A = randn(5, 5, 99);
B = zeros(5, 5, 33);
for i=1:33
B(:, :, i) = sum(A(:, :, (i-1)*3+(1:3)), 3);
end
whos
Name Size Bytes Class Attributes A 5x5x99 19800 double B 5x5x33 6600 double cmdout 1x33 66 char i 1x1 8 double
B
B =
B(:,:,1) = 1.0801 -0.9310 1.6476 3.9098 -0.1822 2.7773 1.0514 2.8541 -1.9000 0.6120 1.0582 -0.4614 0.8884 0.4824 0.5554 -0.5364 0.4871 0.6735 -0.6918 0.7854 -2.3907 1.8485 0.3522 -3.2762 -2.1711 B(:,:,2) = 1.7186 0.5920 3.6962 2.1688 0.1163 -0.7519 -1.6879 3.1578 -3.1428 1.4388 0.0607 2.9797 0.7485 0.6620 0.0260 1.8920 -3.0542 1.0073 1.4882 -0.6512 -4.2737 -0.4719 0.9764 0.6908 1.9635 B(:,:,3) = -1.1917 -0.1001 0.9368 -1.9018 0.7090 1.5334 1.7555 2.1941 -0.6463 -0.1665 -0.2419 0.3022 0.3150 -3.5558 1.1313 -1.6839 0.6759 0.0532 2.8834 4.0220 -0.1851 1.4545 2.3745 -1.1610 1.2608 B(:,:,4) = 0.6287 1.9192 -1.0544 -1.2425 -2.8365 1.4835 0.5123 4.1524 -1.1864 0.1390 0.7249 -0.1715 0.3567 -1.1869 2.5121 -1.0874 1.2256 -0.4822 1.7408 -0.8053 -0.7387 1.7543 1.1213 -4.0384 -0.8762 B(:,:,5) = 0.9368 0.3619 1.2844 -1.2814 -1.2918 -1.4238 0.3363 1.5450 0.0269 -1.8170 0.6068 0.5592 2.0891 -0.9862 -0.2391 -0.4027 -0.5556 -0.5730 1.7127 1.1396 1.8389 -1.2629 3.5192 0.3103 2.6123 B(:,:,6) = -3.2745 1.2307 -1.4399 3.2468 -2.8418 -0.9268 -2.3572 1.5603 1.1992 0.8358 0.3286 -0.3112 0.3418 0.1299 0.3077 0.1179 1.6223 -1.6759 3.0819 0.5428 3.4974 0.7914 1.4008 -0.8006 2.3222 B(:,:,7) = 3.8006 1.8363 2.5171 -0.0303 0.9158 2.4714 0.0860 -1.7693 -0.4328 0.2005 2.2799 -0.9735 -1.7687 0.4138 2.9406 -1.0887 1.7944 1.0271 0.7926 1.2619 -1.3412 -1.9069 2.7119 -3.4371 1.1389 B(:,:,8) = -1.7138 2.3615 2.5694 -0.4497 -4.5408 -1.5113 0.7602 2.1105 -0.3170 -2.6361 -3.1610 -1.4643 0.6216 2.8660 0.0573 -1.6175 4.0008 -0.3381 -0.1984 -0.7947 -1.7819 0.4095 -1.4420 1.5145 -0.3211 B(:,:,9) = 2.3838 2.0878 -0.5382 3.7507 2.0960 1.9347 2.0669 -0.8329 0.3824 0.8640 2.4861 -2.6501 1.7428 -1.7890 -1.6104 -0.7959 0.3277 4.8707 -0.2208 1.2169 -1.9939 -0.6632 -0.0665 -1.7913 1.4307 B(:,:,10) = 1.7708 0.8174 -2.7081 0.5897 -0.6022 -0.1805 0.3482 -1.1240 0.8698 -0.2955 -0.9489 1.3042 -4.6263 1.7611 0.8033 -1.0393 -1.3906 -2.6551 -0.4666 0.3346 2.1117 0.6587 0.1391 -2.2200 1.9483 B(:,:,11) = -1.6108 3.9748 2.3733 -1.2794 -1.1346 1.5313 2.6586 1.2973 1.1206 -0.6783 0.2285 1.3468 -0.3297 -1.4879 0.9589 -3.2108 3.4015 1.2998 -3.2940 0.4316 -1.2495 -3.5360 2.1075 -0.1034 -1.3260 B(:,:,12) = 0.0661 -1.7048 1.9452 3.1399 -3.0431 -0.6224 -1.3920 2.7349 1.5759 1.9048 -2.6062 0.1277 3.5493 0.0089 -6.0951 0.2745 -0.9913 -3.8000 -2.1058 0.0014 -0.6025 -0.3238 0.7430 1.2486 0.3905 B(:,:,13) = 0.5090 -1.8384 4.9040 -0.0834 0.9401 -2.5016 -1.0498 -0.9617 0.1988 -1.6728 3.1996 -2.7104 2.0117 1.0260 -0.3569 3.2603 3.1382 3.0901 0.0855 -0.6663 0.7472 1.9691 0.4188 0.2657 -0.7560 B(:,:,14) = -2.0834 -0.1674 -0.0127 -1.3724 -0.7853 0.0141 -1.2462 -2.0874 -1.8179 -0.6612 1.4417 -0.5028 0.7359 0.5513 -0.0937 0.5833 -2.1986 -1.0589 0.2680 1.2708 1.8445 -1.7178 -0.3624 2.5992 2.4769 B(:,:,15) = -1.9915 0.2211 -0.8792 1.7162 -1.1824 1.8791 0.1338 0.1207 0.7979 0.0575 2.6634 -0.9772 -1.4023 1.9158 -2.0530 -3.5620 0.7934 2.8845 3.0420 -0.4115 -2.0293 3.0953 0.7776 0.0454 -0.6836 B(:,:,16) = 0.2460 -0.8852 2.6075 0.4653 0.5208 0.9171 -2.8741 2.2960 -1.6905 -0.0163 0.1987 0.0810 1.4670 -0.0219 3.1898 -1.1416 0.1643 2.6641 3.5801 0.7277 -2.0222 -0.4112 -1.6089 -2.2642 -2.0376 B(:,:,17) = 0.7975 2.9341 0.3443 0.0866 0.5167 0.1475 -3.4558 1.9223 -2.5965 1.4561 -1.4942 -1.1344 0.9004 -0.6161 1.0252 -0.5623 1.3244 -2.1575 -0.8474 -0.6853 -1.4023 -0.5532 -0.4516 -0.5334 3.4513 B(:,:,18) = -2.9338 0.0491 1.8345 2.9347 -1.9308 -0.3876 3.3523 4.0483 0.2978 -0.5219 2.1096 0.3462 0.7005 -1.5934 2.8639 0.4757 -1.7640 -0.7932 2.9646 -0.7123 -1.2909 -1.8976 1.0907 1.8097 -0.5561 B(:,:,19) = 0.5579 0.2422 -2.9485 0.7972 2.5755 1.0189 0.1914 -0.7493 0.6939 -2.0909 -2.5138 2.6576 -1.2495 -0.5541 2.7864 -1.6242 0.5929 -0.1956 0.4622 -3.3564 -0.2555 -1.3294 2.4360 0.0018 0.2349 B(:,:,20) = -2.7642 -0.5471 0.3265 -1.7913 -2.0071 1.3997 0.1897 0.0740 1.5834 0.1635 0.2456 -3.2479 0.7067 -2.1452 0.9359 -1.1186 0.6781 1.9374 0.0016 -1.4852 0.1581 1.1187 -1.2812 1.5271 2.3767 B(:,:,21) = 1.3027 -3.0669 -2.5140 2.5249 0.3256 1.0849 -2.2210 2.2105 1.0322 -2.7332 1.7464 -1.3768 -0.8949 0.7157 1.6362 0.1681 -1.2050 3.8122 0.3636 1.5360 0.5076 1.6824 -1.2537 -0.1030 0.7563 B(:,:,22) = -0.7558 -1.0014 1.8700 1.9205 -0.6140 0.2165 1.6217 -0.8111 1.0028 2.0232 -2.3559 2.7258 1.7126 -1.8611 0.4371 1.6219 0.7750 -2.5612 0.3213 -2.5177 0.1565 -0.5339 -0.5733 -0.2441 -2.5021 B(:,:,23) = 0.9844 0.8369 0.8553 0.2370 1.1270 2.9168 -0.6636 -0.2539 -0.4327 -0.6501 2.1469 1.4433 1.6019 0.9948 0.2525 1.5140 1.5396 0.9000 0.5947 1.4490 1.0458 0.0183 -1.2318 -0.2988 -2.0634 B(:,:,24) = -0.2771 -1.4910 -2.9626 -1.7318 2.2095 0.9512 -1.1338 0.6782 0.7795 -0.8880 -0.8533 -2.7780 -2.3788 -2.0778 0.2766 -0.9914 -0.2575 -0.3793 -0.1217 0.1563 -2.4972 1.8518 -2.1511 1.8243 -0.6004 B(:,:,25) = 0.2687 -0.3347 1.1227 -0.0886 -2.6626 0.9024 -0.8702 -0.0905 -0.3697 0.1555 -2.9463 -1.2182 -1.1932 0.9498 1.0114 0.2617 0.2796 -0.4914 3.5571 -1.1028 -1.6009 -1.5878 1.3678 -1.3583 -2.3621 B(:,:,26) = 1.2563 0.8366 0.8002 0.6838 0.2330 1.1104 -0.0262 -2.4385 0.4708 -1.7288 -0.1345 0.2320 -1.4339 -0.4139 0.7586 1.0655 2.9163 -0.8192 1.4195 0.5019 1.6090 0.7177 0.0177 1.0356 -2.0008 B(:,:,27) = 1.6343 1.0184 0.8376 -0.9728 0.3353 -2.7207 -0.5291 -0.2911 -1.0033 2.2731 -0.7506 0.7822 2.3866 1.6515 -2.9627 -0.4358 -0.4526 3.2547 -2.1035 -2.0407 0.8323 1.2352 -0.3457 1.4855 0.3752 B(:,:,28) = 1.8239 -0.1335 1.4915 -1.0550 -0.5938 3.7806 0.2710 0.9868 -2.0289 -1.1497 -1.0458 0.4945 0.3546 -0.0739 -1.6005 -0.2407 2.5159 -0.2250 0.5005 1.1066 0.2643 -0.0131 1.3026 1.7734 -0.5729 B(:,:,29) = -0.3810 0.8987 -2.2175 -0.4167 0.5621 -0.5270 0.4304 1.0761 0.1885 0.9786 1.7019 1.0872 -0.9485 0.5736 -2.1015 -1.8118 1.4298 -0.1435 0.7297 0.8214 0.2799 -2.1276 0.8208 -0.1314 -3.5065 B(:,:,30) = -0.1133 -2.7520 -3.2753 -1.0057 -0.8834 0.2685 0.9265 2.2004 -0.9980 0.8306 0.0608 0.3621 -1.8136 0.5018 -3.0189 -1.1764 2.5815 0.0425 -2.5444 -1.3692 -1.1503 -0.2703 -1.2848 -0.1888 -1.1203 B(:,:,31) = -0.6610 -0.8840 0.8206 -0.4026 -0.1174 0.9512 2.4037 1.1887 2.1854 0.1708 1.4476 -1.4069 -2.0353 -2.0397 4.2878 -2.4774 -0.8173 -2.1959 -2.1793 -0.7268 1.2948 0.3052 2.3863 -1.2332 -1.6261 B(:,:,32) = -0.4802 -0.6304 -2.3091 -0.7794 1.3444 2.2289 0.2194 1.5060 0.0024 1.3949 -1.2486 -0.4703 2.1090 0.6853 -1.4494 5.4418 -1.3608 2.3341 -0.5118 5.2558 1.0397 1.5947 -1.6032 -3.4416 2.3021 B(:,:,33) = -1.9845 0.9943 1.9642 -0.4459 0.8147 1.7308 -3.0916 -3.4756 3.4416 4.2824 -1.0330 3.4350 -3.7624 1.5342 -0.7833 -1.1288 0.0081 -2.4436 -2.2191 -1.0281 0.3592 -1.9227 -1.7233 0.3510 1.2419
  2 Kommentare
rakesh kumar
rakesh kumar am 16 Aug. 2022
thanks a lot
Image Analyst
Image Analyst am 16 Aug. 2022
To make it more general and robust, you'd do
A = randn(5, 5, 99);
[rows, columns, slices] = size(A)
B = zeros(rows, columns, slices/3);
for k = 1 : slices/3 % or 1 : size(B, 3)
B(:, :, k) = sum(A(:, :, (k - 1) * 3 + (1 : 3)), 3);
end
whos
B
We don't recommend using i (the imaginary variable) as a loop counter, and it's more robust to preallocate the size of B based on the size of A. You might also check in advance if the number of slices is not a multiple of 3 and throw up a friendlier error if it's not.

Melden Sie sich an, um zu kommentieren.

Weitere Antworten (1)

Image Analyst
Image Analyst am 16 Aug. 2022
OK, so go ahead. I know you did not actually ask a question, but this is how you must proceed.
sum1 = (A1+A2+A3) ;
sum2 = (A4+A5+A6);
% Etc
sum33 = (A97+A98+A99);
Yes, you'll have 33 lines of code rather than a small, compact for loop, but that is the penalty you must pay for unwisely having 99 individual, separately named variables instead of having a higher dimensional array.
  3 Kommentare
1 älteren Kommentar anzeigen
Image Analyst
Image Analyst am 16 Aug. 2022
Bearbeitet: Image Analyst am 16 Aug. 2022
If you have a 3-D array, like you should rather than separately named variables, you can do this:
[rows, columns, slices] = size(A)
sums = zeros(rows, columns, slices/3, class(A));
slice = 1;
for k = 1 : 3 : slices
sums(:, :, slice) = sum(A(:, :, k : k+2), 3);
slice = slice + 1;
end
rakesh kumar
rakesh kumar am 16 Aug. 2022
thanks

Melden Sie sich an, um zu kommentieren.

Kategorien

Mehr zu Creating and Concatenating Matrices finden Sie in Help Center und File Exchange

Tags

Community Treasure Hunt

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

Start Hunting!

Translated by