i want to replace cell data to index.

Hello,

I'm poor at English so write simple code..

cell data is a = {[1 2 3 4 ] [5 6] [ 7 8 9]} ; index = [2 1 3] ; -> 10 11 12

the result is a = {[1 10 3 4] [ 11 6] [7 8 12 ]}

cell data size are different.

i want to replace the cell data at the same time. How can i replace the data without using for loop. i don't know how to use cellfun function or another method.

for example,

at matrix a = [1 2 3 4 5] ; a([1 3]) = [100 200 ] ; the result is a=[100 2 200 4 5] ;

i want like this at cell.

thanks.

[Jos (10584)]

Do you want to replace a value or insert it?

[Seongjin]

I want to replace a value .

Answer 1

[Azzi Abdelmalek]

I think this is the best way:

a = {[1 2 3 4 ] [5 6] [ 7 8 9]} ;
index = [2 1 3] ;
b=[10 11 12];
for k=1:numel(a)
  a{k}(index(k))=b(k);
end
celldisp(a)

[Seongjin]

Thank you for your answer. But, i don't want to use for loop.

[Azzi Abdelmalek]

Without for loop, but not necessary faster

a = {[1 2 3 4 ] [5 6] [ 7 8 9]} ;
index = [2 1 3] ;
b=[10 11 12];
nn=1:numel(index);
out=arrayfun(@(ii) strrep(a{ii},a{ii}(index(ii)),b(ii)),nn,'un',0);
celldisp(out)

[Seongjin]

Thank you so mush. Good luck.

i don't know. the run time of for-loop is faster than the runtime of function handle.

[Azzi Abdelmalek]

Sometimes, the for loop do the job.

Answer 2

[Jos (10584)]

To insert values at a location in a cell of A:

A = {[1 2 3 4 ] [5 6] [ 7 8 9]} ;
index = [2 1 3] ;
B = [10 11 12] ;

fh = @(k) insertrows(A{k}.', B(k), index(k)-0.5).' ; % offset of 0.5 to insert _before_
OUT = arrayfun(fh,1:3,'un',false)

INSERTROWS can be found here:

http://www.mathworks.com/matlabcentral/fileexchange/9984-insertrows-v2-0-may-2008

[Seongjin]

Thank you so mush. Good luck.

But,, I want to replace value,, not insert.

i try to solve the problem for your reference.

Answer 3

[Andrei Bobrov]

a = {[1 2 3 4 ] [5 6] [ 7 8 9]} ; 
index = [2 1 3] ;
b = [10 11 12];

n = cellfun(@numel,a);
v = [a{:}];
ii = index +[0 cumsum(n(1:end-1))];
v(ii)=b;
out = mat2cell(v,1,n);

Answer 4

[Jos (10584)]

To replace values at a location in a cell of A:

Step 1: Create a function like this

function X = MyReplace(X,ii,V)
% MyReplace(X,ii,V) replaces X(ii) with V
X(ii) = V ;

Step 2: Use it like this:

% Example data
  A = {[1 2 3 4 ] [5 6] [ 7 8 9]} ;
  index = [2 1 3] ;
  B = [10 11 12] ;

% Engine
  fh = @(k) MyReplace(A{k},index(k),B(k)) ;
  OUT = arrayfun(fh,1:3,'un',false)