REPLACE

Replace several elements at once

Description

Current version 1.4, dec 2006

REPLACE - Replace Elements
B = REPLACE(A,S1,S2) returns a matrix B in which the elements in A that are in S1 are replaced by those in S2. In general, S1 and S2 should have an equal number of elements. If S2 has one element, it is expanded to match the size of S1. Examples:
       replace([1 1 2 3 4 4],[1 3],[0 99]) % -> [ 0 0 2 99 4 4]
       replace(1:10,[3 5 6 8],NaN) % -> [ 1 2 NaN 4 NaN NaN 7 NaN 9 10]
       replace([1 NaN Inf 8 99],[NaN Inf 99],[12 13 14]) % -> [1 12 13 8 14]

[B, TF] = REPLACE(A,S1,S2) also returns a logical vector TF of the same size as A. TF is true for those elements that are replaced.

A and S1 can be cell arrays of strings. In that case S2 should be a cell array as well but can contain mixed types.
Example:
     replace({'aa' 'b' 'c' 'a'},{'a' 'b'}, {'xx' 2}) %-> {'aa' [2] 'c' 'xx'}
 
If S2 is empty, the elements of A that are in S1 are removed.
Examples:
       replace(1:5,[2 4],[]) % -> [1 3 5]
       replace({'aa' 'a' 'b' 'aa' 'c'},{'aa','c'},{}) % -> {'a', 'b'}
 
See also FIND, STRREP, REGEXPREP, ISMEMBER

Authhor's note: I failed to find such a utility in matlab or on the FEX so far. Please correct me if there are better alternatives.

• MATLAB release: MATLAB 6.5 (R13)

[Jos van der Geest]

An update is on it's way ...

[John D'Errico]

This seems to work now. Its the kind of thing that gets asked for repeatedly on the news group, so it is clearly of value. Good help. Does what it says.

[Liliana Rincon]

I got this file like a month ago and it was working perfectly. I was using it to replace a specific number in a really big arrays for NaN. But it stopped working a couple of weeks ago. Do you know why?

[Balajee Ananthasayanam]

It worked for me. Thanks

[Rodolfo Venegas]

thank you for your work, but the script is not for matrix, its only for vectors.
for example
>> replace([1 1 2 3 4 0],0, 99)

ans =

     1 1 2 3 4 99

But, when you use the function with a matrix:

>> replace([1 1 2 3 4 0; 1 2 0 3 6 7],0,99)

ans =

     1 1 2 3 4 0
     1 2 0 3 6 7

However is really easy to extend

Thanks again
Rodolfo

[Jos (the author)]

Thanks Rodolfo for pointing this out. New version (1.3) is on its way.

[Ubagucha Puchonova]

Works fine, although you can run it through M-Lint in r2006 to make a code optimization.

[Jos van de Geest]

Thanks Ubagucha Puchonova, for your comments. Unfortunately, the suggested MLint improvements are not available for release R13 ...

[S Gorniak]

Thanks for writing this program! Couldn't find other programs to replace NaNs with zeroes, so this was awesome.

[sukuchha shrestha]

dear Gorniak,

there is a inbuilt program in matlab to replace NANS with zero.

A(isnan(A))=0;