spliting up a char array

If I have a char variable... say x=2.1*3C how can i get 2.1 by itself as its own variable

[me]

I read a large text file full of GPS data and divided the string up by the using xc=textscan(scol{k,1}, '%s', 'Delimiter',','). Its in a for look and it scans sentences that look like this: $GPGSA,A,3,04,05,,09,12,,,24,,,,,2.5,1.3,2.1*3C

Anyway, one of the points in this cell(scol{1,1}{18,1}) looks like this 2.1*3C but for my project I only need the numbers before the *. I have no idea how to get it or how I could have written my code differently.

[me]

i ment for loop not 'for look'

Answer 1

[Stephen23]

One answer to your question is to use indexing:

>> S = '2.1*3C'
S =
2.1*3C
>> T = S(1:3)
T =
2.1

If you want this as a numeric value then:

str2double(S(1:3))

Although there are many possible answers to your question, I suspect that this whole thing could be avoided by better planning and data concept. Could you please give us more information about what you are trying to do with the 2.1, and where this string comes from. Probably passing the data in something more suitable than a string would make your programming much simpler and more reliable.

[me]

Thank you! that worked perfectly.

[Image Analyst]

If it was "perfect" then you can also "vote" for the answer to give him double reputation points. That'd be a nice thing to do for him.

Answer 2

[Image Analyst]

Some of the millions of ways:

% Set up (if the x= is part of the string):
myString = 'x=2.1*3C'
% Find the equal sign:
equalIndex = strfind(myString, '=');
% Find the *:
starIndex = strfind(myString, '*');
% Now get 2.1 in its own character variable:
itsOwnVariable = myString(equalIndex+1:starIndex-1) % as another string
% Now get 2.1 in its own character variable:
itsOwnVariable = str2double(myString(equalIndex+1:starIndex-1)) % As a double

% Set up with no x= in the string:
myString = '2.1*3C'
% Now get 2.1 in its own character variable:
itsOwnVariable = myString(1:3) % as another string
% Now get 2.1 in its own character variable:
itsOwnVariable = sscanf(myString, '%f') % As a double