How to get the absolute value of the a vector inside an array?

16 次查看（过去 30 天）
Ana Bianco
Ana Bianco 2019-9-10
编辑： Stephen23 2019-9-11
Hi there, I am trying to extract the absolute value of the column vectors inside an array, but it keep giving me the message: Array indices must be positive integers or logical values., for the following code:
absvec = [];
for a = 1:270
for b =1:10
abs(H{a,b}) = absvec (a,b),
end
end
can anyone help me?
  2 个评论
Adam Danz
Adam Danz 2019-9-10
编辑：Adam Danz 2019-9-10
Either that's not the error message you're getting or you shared the wrong code with us.
The error message returned by your code is "Index in position 1 exceeds array bounds." (r2019a) Of course this is happeneng because absvec is empty and you're trying to index it.
do you mean
absvec (a,b) = abs(H{a,b}) % ???

请先登录，再进行评论。

请先登录，再回答此问题。

采纳的回答

Sebastian Körner
Sebastian Körner 2019-9-10
relly not sure if this is what your question is about but maybe it helps.
since you provided no data to your problem i created some example data myself.
H ={[5,-6],[5,-6];[7,-8],[7,-8];[5,-6],[5,-6];[7,-8],[7,-8]};
v=1;
for i=1:4
for k=1:2
h(:,v)=abs(H{i,k});
v=v+1;
end
end
input: cell array with cevtors in each cell
output: a vector with the absolute values of each vector of the cell array
  2 个评论
Stephen23
Stephen23 2019-9-11
编辑：Stephen23 2019-9-11
Simpler and more efficient with a comma-separated list:
>> out = abs(cat(1,H{:}))
out =
5 6
7 8
5 6
7 8
5 6
7 8
5 6
7 8
Timing (1e5 iterations):
Elapsed time is 13.833 seconds. % nested loops
Elapsed time is 2.239 seconds. % comma-separated list

请先登录，再进行评论。

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Matrix Indexing 的更多信息

标签

产品


版本

R2018a

Community Treasure Hunt

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

Start Hunting!

Translated by