Why doesn't this matlab code work?!

s={'CCCAGCTCCCGAATTCCCCAGCTA'}; 
rec={'AG^CT'}; 
x=strfind(rec,'^');
y=rec;
y(x)=[]

I get:

Error using subsindex Function 'subsindex' is not defined for values of class 'cell'.

Error in Untitled555555 (line 5) y(x)=[]

Answer 1

[Stephen23]

Because x is a cell array, and you are trying to use this to index into the variable y, which is not supported in MATLAB (indices must be numeric or logical). If you have a look in your workspace you will find that all of your variables are in fact cell arrays... is this intentional? Depending on your application it may be unnecessary to use cell arrays at all:

s = 'CCCAGCTCCCGAATTCCCCAGCTA';
rec = 'AG^CT';
x = strfind(rec,'^');
y = rec;
y(x)=[];

using no cell arrays, and works without error. If you think you really do need to use cell arrays, please post more details of what you are trying to achieve and we can help you further with the best way to code it using MATLAB.

These might be of interest:

http://www.mathworks.com/help/matlab/math/matrix-indexing.html

http://www.mathworks.com/company/newsletters/articles/matrix-indexing-in-matlab.html

Answer 2

[Image Analyst]

First read this http://matlab.wikia.com/wiki/FAQ#What_is_a_cell_array.3F

then try this:

rec={'AG^CT'}; 
x=strfind(char(rec),'^')
y=rec
y{1}(x)=[]

Answer 3

[Ahmad]

couldn't understand what it says, plus i'm trying to add this line too, can u fix it:

cut_position= strfind(s,y) + x -2;

it's giving me this error: Error using cell/strfind (line 32) If any of the input arguments are cell arrays, the first must be a cell array of strings and the second must be a character array.

Error in Untitled555555 (line 6) cutpos= strfind(s,{y}) + x -2;

[Image Analyst]

Your error doesn't match your code. In the strfind, do you have y or {y} ? And if it's {y}, then why???

Say, did you ever look at the FAQ link I gave you? Please do. I gave it to you because I think it will help you understand cell arrays. If you can't understand the FAQ, let me know and I'll clarify it.

Answer 4

[Ahmad]

thank u so much for offering help, i understand what a cell array is now, but i don't understand thsis syntax "y{1}", and sorry i was trying different things so the rror was for a previous code, but now i get this error:

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

Error in Untitled555555 (line 6) cut_position= strfind(s,y{1}) + x -2;

[Image Analyst]

Not sure you do understand cells yet because you'd know that y{1} means "contents of the first cell of y". So y is a cell or a cell array (a columns or row vectors). Then 1 means take the first cell in the row, or first cell in the column, and get the contents of it, which could be virtually anything - a string, a structure, a double, an image, even another cell. In your case y is a cell array where the cells contain strings, so y{1} is a string.