Finding strings in a 21 x 1 cell array.

I have a cell array that looks like this:newsequence =

    'CGT'
    'GAC'
    'AGT'
    'CCT'
    'CTC'
    'CTT'
    'TAC'
    'CGA'
    'AAG'
    'GGA'
    'AGA'
    'ATA'
    'AAA'
    'GTG'
    'GCG'
    'TGA'
    'TGC'
    'ATT'
    'ACG'
    'CCT'
    'GCA'

I am interested in finding the location of 'TAC'. When I use this function: found=strfind(newsequence,'TAC'); I end up with a cell array with all zeros and a 1 in the 7th row. I want it to display a 7 because that is the location of 'TAC', but I can't seem to figure it out.

Answer 1

[Mohammad Abouali]

newsequence  = {'CGT'
    'GAC'
    'AGT'
    'CCT'
    'CTC'
    'CTT'
    'TAC'
    'CGA'
    'AAG'
    'GGA'
    'AGA'
    'ATA'
    'AAA'
    'GTG'
    'GCG'
    'TGA'
    'TGC'
    'ATT'
    'ACG'
    'CCT'
    'GCA'};

mask=strcmpi(newsequence ,'TAC');
rows=find(mask)

    rows =

         7

or you could combine both command in one as:

rows=find( strcmpi(newsequence ,'TAC') )

Answer 2

[Star Strider]

The function is returning a logical array of row indices. To convert it to a numerical value for the actual row number of every matching row, add a call to the find function:

found = find(strfind(newsequence,'TAC'));

I didn’t specifically test this, but it should work.

[JE]

Undefined function 'find' for input arguments of type 'cell'.

I tried this already. :(

[Star Strider]

This looks tortured, but it works:

found = (strfind(newsequence,'TAC'));
found = find(cell2mat(cellfun(@(x)~isempty(x), found, 'Uni',0)))

found =
     7

Answer 3

[Image Analyst]

Try ismember(). Here I'm using CCT to show what happens if you have the string in more than one row:

ca = {'CGT'
    'GAC'
    'AGT'
    'CCT'
    'CTC'
    'CTT'
    'TAC'
    'CGA'
    'AAG'
    'GGA'
    'AGA'
    'ATA'
    'AAA'
    'GTG'
    'GCG'
    'TGA'
    'TGC'
    'ATT'
    'ACG'
    'CCT'
    'GCA'}
[ia, ib] = ismember(ca, 'CCT')
rows = find(ia)

[JE]

rows =

     []

I keep getting this as the answer.