extracting repeated strings line from text file

I need to extract repeated strings' lines from the attached text file. For example there are 2 lines which start with "PG01" string in the data file. I need to extract 2nd and 4th column of these lines as follows;

array_PG01=[ 2621.231803 -16886.323981 -20336.445346; 4678.863852 -17810.095582 -19125.227353];

Which code gives me this array?

Thanks in advance.

Answer 1

[Stephen23]

fid = fopen('data.txt','rt');
str = fscanf(fid,'%c',Inf);
fclose(fid);
C = regexp(str,'^PG01( +\S+)+\s+$','lineanchors','tokens');
C = regexp(vertcat(C{:}),'\S+','match');
N = str2double(vertcat(C{:}));

the output variable is:

>> N
N =
   2621.231803   -16886.323981   -20336.445346   -8.459625     11    7    6    134
   4678.863852   -17810.095582   -19125.227353   -8.459167     11    7    6    131

You can pick whatever columns you need:

>> N(:,[1,2,4])
ans =
               2621.231803             -16886.323981                 -8.459625
               4678.863852             -17810.095582                 -8.459167

[Stephen23]

See my other answer for a more versatile solution:

http://www.mathworks.com/matlabcentral/answers/265227-using-regexp-for-space-delimited-strings-in-text-file