Trying to replace for loop with faster code

1 次查看(过去 30 天)
I have the following code in a rather large script, which unfortunately is VERY slow:
for x = 1:size(table1)
for y = 1:size(Loc_all)
if ismember(table1.Loc(x),Loc_all(y)) == 1
table1.dur(x) = t_avg(y);
break
end
end
end
It definitely works, but again the duration time is not "workable".
So I tried the following:
f = ismember(table1.Loc,Loc_all) == 1;
[IndexM, IndexN]=find(f);
table1.dur(IndexM) = t_avg(IndexN);
It works for IndexM which defines the location in table1.Loc - but it wont work for IndexN - all I get here is 1's. What am I missing?
As you can see t_avg and Loc_all have the same size, as do table1.Loc and table1.dur - I'm expecting IndexN to give the Location in Loc_all where a match happens.
Loc_all only has unique values. table1.Loc is a large table of values which may or may not be in Loc_all.
Any hints are very much appreciated!
Thank you!
  1 个评论
DGM
DGM 2021-8-23
It would help to provide some succinct example data to demonstrate what exactly you're dealing with.

请先登录,再进行评论。

采纳的回答

Voss
Voss 2021-8-23
The second output argument of the find function is column indices. In order to get indices in Loc_all where a match happens, you can use the second output argument of ismember:
[f, IndexN] = ismember(table1.Loc,Loc_all); % f is the same as your f; IndexN is what you expect, except it has zeros where no match occurred (i.e., where f is false)
IndexN = IndexN(f); % keep only the IndexN where a match occurred
IndexM = find(f); % convert logical index f to integer index IndexM; IndexM is the same as your IndexM

更多回答(0 个)

类别

Help CenterFile Exchange 中查找有关 Loops and Conditional Statements 的更多信息

Community Treasure Hunt

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

Start Hunting!

Translated by