Unable to perform assignment because the left and right sides have a different number of elements.

Question

ekta yadav 2020-9-12

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/592615-unable-to-perform-assignment-because-the-left-and-right-sides-have-a-different-number-of-elements

评论： Image Analyst 2020-9-13

I am calculating first and second derivative for getting threshold values for ecg. but getting error. Please help.

for n=5:numel(ecgBR)
    ecg_dif(n)=abs(ecgBR(n,1)-ecgBR(n-2,1));
    ecg_dif2(n,1)=abs(ecgBR(n,1)-2*ecgBR(n-2,1)+ecgBR(n-4,1));
end

ERROR:Unable to perform assignment because the left and right sides have a different number of elements.

ecgBR=1X3600 double matrix

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。

请先登录，再回答此问题。

Answer 1

Image Analyst 2020-9-12

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/592615-unable-to-perform-assignment-because-the-left-and-right-sides-have-a-different-number-of-elements#answer_493516

在 MATLAB Online 中打开

Since ecgBR has only one row, not n, you cannot do ecgBR(n, 1), which is the nth row in column 1. But you have 3600 columns, not 1, and 1 row, not 3600. Get rid of the ,1:

for n=5:numel(ecgBR)
    ecg_dif(n)=abs(ecgBR(n)-ecgBR(n-2));
    ecg_dif2(n)=abs(ecgBR(n)-2*ecgBR(n-2)+ecgBR(n-4));
end

2 个评论
显示无隐藏无

ekta yadav 2020-9-13

在 MATLAB Online 中打开

*Thanks @Image Analyst. It worked. Really saved lot of time of mine.

*I am facing one more problem while detecting peaks of ECG. Please help

[pks3,locs_R2] = findpeaks(ecgBR,'MinPeakHeight',0.6,'MinPeakDistance',200); %R peakes
ecg_inv=-ecgBR;
[pks2,locs_S] =findpeaks(ecg_inv,'MinPeakHeight',0.4,'MinPeakDistance',200); %S peaks
[~,min_locs] = findpeaks(ecg_inv,'MinPeakDistance',19); %Q peaks
locs_Q = min_locs(ecg_inv(min_locs)=>0.12 & ecg_inv(min_locs)=<0.3);