Find an index of a cell whose element satisfies a condition

25 visualizzazioni (ultimi 30 giorni)
Is there a way to economically fix the code below to make it work so that it returns the index of the cell element whose array has the number 1 in its second column?
c = {[1,2,3], [2,3,1], [3,1,2]};
find(c{:}(:,2)==1) % expected result is the cell index 3
The code above gets me this error:
Intermediate brace {} indexing produced a comma-separated list with 3 values, but it must produce a single value to perform subsequent indexing operations.
I came up with this one
find(~cellfun(@isempty,(cellfun(@(x) find(x(:,2)==1,1),c,'un',0))))
but I would like to find some other efficient ways of doing it.

Risposta accettata

Star Strider
Star Strider il 18 Giu 2021
Try this —
c = {[1,2,3], [2,3,1], [3,1,2]};
idx = cellfun(@(x)x(:,2)==1, c, 'Unif',0)
idx = 1×3 cell array
{[0]} {[0]} {[1]}
Out = find([idx{:}])
Out = 3
.

Più risposte (1)

DGM
DGM il 18 Giu 2021
This is one way:
c = {[1,2,3], [2,3,1], [3,1,2], [1,2,3], [2,3,1], [3,1,2]};
idx = find(cellfun(@(x) x(2)==1,c))
idx = 1×2
3 6
  2 Commenti
Diaa
Diaa il 18 Giu 2021
I think your code will fail in this example
c = {[1,2,3;1,2,3], [2,3,1], [3,1,2;3,6,9]}; find(cellfun(@(x) x(2)==1,c))
DGM
DGM il 18 Giu 2021
Ah yeah. I had read "second column" as "second element".

Accedi per commentare.

Prodotti


Release

R2021a

Community Treasure Hunt

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

Start Hunting!

Translated by