Using find in a for loop error

2018 2 12
2 个回答
回答已采纳
更新时间：2018 2 12
1 次查看（30 天）

0 个投票

I have a large matrix with values of "period" p - I am testing this part of my code where I find what row p belongs to in order to access the corresponding row later in my code. However for some reason this will only run three times (so until cct=3) before i get the error: Assignment has more non-singleton rhs dimensions than non-singleton subscripts; error position1(cct,1)=find(p==pp)
*
p=AAA(1:end-1,1); %%%returns 10000x1 matrix of values 0 to 1 in 0.001 steps
cct=1;
for pp =0.1:0.1:0.5;
position1(cct,1)=find(p==pp);
position2=position1(cct,1);
valuep=p(position2,1); %%%to check it is the correct value
cct=cct+1;
end*

1 个评论
显示 -1更早的评论 隐藏 -1更早的评论

Serena Campbell
Serena Campbell 2018-2-12
编辑：Serena Campbell 2018-2-12
So - I put the output into a cell and a strange thing happens - it always skips the third value (no matter what the value is!) and continues nicely after? (see attached output)
p=AAA(1:end-1,1);
cct=1;
for pp =0.4:0.1:1;
test(cct,1)=cct;
valuepp(cct,1)=pp;
x{cct,1}=find(p==pp);
%
cct=cct+1;
end

请先登录，再进行评论。

请先登录，再回答此问题。

 采纳的回答

Matt J
Matt J 2018-2-12
编辑：Matt J 2018-2-12

0 个投票

You would need to give us AAA in a .mat file to be certain. Most likely, however, pp is not close enough to 0.6 (due to floating point error) to match a value in AAA. Use a tolerance:
x{cct,1}=find(abs(p-pp)<smallnumber);

更多回答（1 个）

Serena Campbell
Serena Campbell 2018-2-12

0 个投票

I worked it out! It must have been a precision problem, as this fixed it:
https://uk.mathworks.com/matlabcentral/answers/17534-find-function-precision-problem

类别

在 帮助中心 和 File Exchange 中查找有关 Loops and Conditional Statements 的更多信息

标签

Community Treasure Hunt

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

Start Hunting!

Translated by