Problem with dimensions, filling a matrix in a for loop

Question

Bran 2014-2-4

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/114824-problem-with-dimensions-filling-a-matrix-in-a-for-loop

评论： Bran 2014-2-6

I am trying to work out the root mean square of my data in sections of 2 seconds. However, the dimensions the matrix Az1 etc is causing an error; he is my code;

clc
clear all;
A = mydata
A1=Az(:,1);
A2=Az(:,2);
A3=Az(:,3);
A1star = padarray(Az1,[0 3],'symmetric','post');
A2star = padarray(Az2,[0 3],'symmetric','post');
A3star = padarray(Az3,[0 3],'symmetric','post');
for i = 1:(length(Az)/120);
A1(i,:) = Az1star(i:i+120*i);
RMS1(i) = sqrt(mean(A1(i,:).^2));
A2(i,:) = Az2star(i:i+120*i);
RMS2(i) = sqrt(mean(A2(i,:).^2));
A3(i,:) = Az3star(i:i+120*i);
RMS3(i) = sqrt(mean(A3(i,:).^2));
end
Endpoint = length(RMS3);
Val = (length(Az)/60);
time = linspace(0, Val, Endpoint);
figure (1)
plot(time,RMS1)
figure (2)
plot(time,RMS2)
figure (3)
plot(time,RMS3)

Any tideas how to fix this problem?

2 个评论
显示无隐藏无

dpb 2014-2-4

在 MATLAB Online 中打开

>> help padarray
padarray not found.

No idea what it is, is supposed to do.

But, there is no Az1, etc., so it's not surprising that would be a problem.

Plus, creating variables of different names with a subscript difference is a sign of poor data design choice--use another level of indexing or a structure or some other similar storage instead.

Walter Roberson 2014-2-4

paddarray is here

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Walter Roberson 2014-2-4

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/114824-problem-with-dimensions-filling-a-matrix-in-a-for-loop#answer_123260

You "clear all" so no variable "Az" or "Az1" etc will be in your workspace. Not unless "mydata" is a function that does assignin('caller') which is a bad idea.

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

Answer 2

Bran 2014-2-4

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/114824-problem-with-dimensions-filling-a-matrix-in-a-for-loop#answer_123264

在 MATLAB Online 中打开

sorry guys that is an old code where I had changed variables names

the actual code is as follows;

clc
clear all;
A = mydata
A1a=A(:,1);
A2a=A(:,2);
A3a=A(:,3);
A1star = padarray(A1,[0 3],'symmetric','post');
A2star = padarray(A2,[0 3],'symmetric','post');
A3star = padarray(A3,[0 3],'symmetric','post');
for i = 1:(length(A)/120);
A1(i,:) = Az1star(i:i+120*i);
RMS1(i) = sqrt(mean(A1(i,:).^2));
A2(i,:) = Az2star(i:i+120*i);
RMS2(i) = sqrt(mean(A2(i,:).^2));
A3(i,:) = Az3star(i:i+120*i);
RMS3(i) = sqrt(mean(A3(i,:).^2));
end
Endpoint = length(RMS3);
Val = (length(Az)/60);
time = linspace(0, Val, Endpoint);
figure (1)
plot(time,RMS1)
figure (2)
plot(time,RMS2)