Adding specified loop outputs

Question

S 2024-3-28

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2099916-adding-specified-loop-outputs

评论： S 2024-4-11

I am trying to make a figure which plots the sum of 3 specific loop outputs. output is the different outputs of the loop and I am trying to get the sum of output 1, 2, and 3. This is what I have:

figure

Sum1=sum(output(1:3));

plot(t,Sum1)

But I am just getting a blank graph and Sum1 for some reason has a value of 0 in my workplace. I am not sure which part of what I am doing is incorrect. Thank you for your time!

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S 2024-3-30

>> size(output)

ans =

5 2000

@Mathieu NOE

Torsten 2024-3-30

编辑：Torsten 2024-3-30

在 MATLAB Online 中打开

Example:

output = rand(5,2000)
output = 5×2000
    0.0093    0.4352    0.6442    0.8223    0.0669    0.0750    0.1579    0.4659    0.4245    0.6393    0.5641    0.4505    0.4841    0.5146    0.3356    0.3269    0.7271    0.9070    0.5396    0.0868    0.7764    0.3069    0.7120    0.8052    0.9633    0.6658    0.3569    0.1724    0.1989    0.1068
    0.5921    0.7917    0.6307    0.8559    0.3566    0.4708    0.3033    0.5932    0.8028    0.4506    0.3292    0.9448    0.2092    0.5576    0.1514    0.5201    0.8899    0.5369    0.4797    0.8613    0.6280    0.1493    0.3335    0.0613    0.5330    0.3729    0.5056    0.2013    0.3167    0.1885
    0.0947    0.8074    0.7094    0.3982    0.4959    0.4298    0.9395    0.8940    0.6521    0.5169    0.6788    0.1383    0.9413    0.5478    0.0879    0.6249    0.1888    0.8520    0.4720    0.5320    0.0991    0.5874    0.9938    0.3726    0.8688    0.4819    0.6446    0.2709    0.1690    0.0696
    0.7237    0.6625    0.5572    0.2795    0.1393    0.5328    0.8897    0.1949    0.1757    0.2561    0.0574    0.4576    0.8966    0.7007    0.4071    0.4533    0.5061    0.2979    0.8647    0.7720    0.0163    0.8398    0.7416    0.2130    0.3288    0.0865    0.1613    0.2869    0.6096    0.1663
    0.8057    0.2727    0.5270    0.3867    0.4939    0.0631    0.1537    0.0135    0.6568    0.6885    0.1418    0.0855    0.8256    0.8523    0.3056    0.7419    0.5254    0.7348    0.0874    0.6650    0.5307    0.6938    0.7397    0.1528    0.8003    0.1851    0.3351    0.1735    0.0691    0.5860
<mw-icon class=""></mw-icon>
<mw-icon class=""></mw-icon>
output(1:3)
ans = 1×3
    0.0093    0.5921    0.0947
<mw-icon class=""></mw-icon>
<mw-icon class=""></mw-icon>
Sum1=sum(output(1:3))
Sum1 = 0.6961

Thus you try to plot one single value (which seems to be 0 in your case).

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Answer 1

Mathieu NOE 2024-4-2

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2099916-adding-specified-loop-outputs#answer_1434776

在 MATLAB Online 中打开

hello again

seems to me you want to sum the first 3 rows so

it should be :

Sum1=sum(output(1:3,:)); instead of Sum1=sum(output(1:3));

output = rand(5,2000)

output = 5x2000

0.1791 0.8425 0.6411 0.9862 0.3772 0.5695 0.0062 0.4191 0.0342 0.4738 0.1301 0.5518 0.6119 0.1510 0.9088 0.5260 0.4196 0.2989 0.1783 0.3134 0.7180 0.3725 0.1104 0.1097 0.2979 0.1851 0.7062 0.0656 0.1199 0.9486 0.5756 0.5375 0.3127 0.3970 0.1694 0.3851 0.8991 0.5512 0.2973 0.0736 0.0879 0.9771 0.1746 0.9450 0.8210 0.4277 0.6274 0.3267 0.7170 0.9286 0.1474 0.6039 0.4600 0.6433 0.4516 0.5993 0.9955 0.5155 0.3603 0.3852 0.1793 0.2607 0.9741 0.4219 0.0558 0.7762 0.7187 0.9905 0.8076 0.6963 0.0663 0.6098 0.1652 0.8677 0.4870 0.6077 0.4855 0.3860 0.0821 0.3845 0.3874 0.3454 0.6813 0.9306 0.7205 0.9261 0.8512 0.6857 0.4511 0.6153 0.8288 0.7844 0.1568 0.0911 0.2925 0.2977 0.1513 0.5298 0.4435 0.7714 0.5839 0.6496 0.3966 0.9823 0.9219 0.1772 0.1597 0.4256 0.9880 0.2713 0.7444 0.5459 0.4914 0.8019 0.6221 0.8412 0.1941 0.7266 0.0968 0.4999 0.9924 0.3889 0.5036 0.9485 0.9013 0.6529 0.4048 0.1062 0.2379 0.2751 0.9468 0.3906 0.3642 0.5598 0.9254 0.3007 0.4848 0.8409 0.0269 0.0066 0.3663 0.7956 0.3960 0.0903 0.1309 0.7850 0.9601 0.3460 0.0059 0.7290

<mw-icon class=""></mw-icon>

Sum1=sum(output(1:3,:))

Sum1 = 1x2000

0.9340 1.6407 1.9280 1.8050 0.6024 1.7308 1.6240 1.9609 1.1390 1.2437 0.2843 2.1387 0.9517 1.9636 2.2169 1.5615 1.5326 1.0116 0.9774 1.6264 1.2528 1.3218 1.2517 1.6836 1.4700 1.7104 2.5530 1.2668 0.9312 1.9491

<mw-icon class=""></mw-icon>

plot(Sum1)

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Stephen23 2024-4-9

"So this works great until I use any number above 5 as start or finish then I get: Index in position 1 exceeds array bounds. Index must not exceed 5."

Of course you will get that error: if you matrix only has five rows (as with the example give by Mathieu NOE) then what do you expect MATLAB to do when you try to access a non-existent sixth row? Or for that matter, any other row that does not exist.

S 2024-4-11