read numbers from mixed string

hi, I want to read numbers from mixed string and write into a file. I've been trying to do so but cant get it to work. my data file has three variables with values in it like

    % xxx: 0.020000unit1
    % yyy: 40.537015180unit2
    % zzz: 0.021517281unit3
    %----------------------
    %data continues with ---- break

    &=%----------------------
      %following code is for only one variable which obviously isn't working
        clc
        clear all

        fid1=fopen('newdata.txt','r')
        fid2=fopen('newdata1.txt','w')
        % save data into a new file
        while ~feof(fid1)
            line=fgets(fid1)
            A=sscanf(line,'xxx: %funit1\n')
            fprintf(fid2,'%f',line)
        end
        fclose(fid1)
        fclose(fid2)
        %fclose all

Answer 1

[Simon Henin]

You need to print the variable A (not "line") to the newdata1 file. Also a quick modification will allow it to work on all the variables (xxx,yyy,zzz):

fid1=fopen('newdata.txt','r')
fid2=fopen('newdata1.txt','w')
% save data into a new file
while ~feof(fid1)
    line=fgets(fid1)
    A=sscanf(line,[line(1:3) ': %funit1\n'])
    fprintf(fid2,'%f\n',A)
end
fclose(fid1)
fclose(fid2)

[Suresh Dahal]

Getting an err ‘index exceeds matrix dimensions’

[Walter Roberson]

fid1=fopen('newdata.txt','r')
fid2=fopen('newdata1.txt','w')
% save data into a new file
while ~feof(fid1)
    line=fgets(fid1)
    if length(line) >= 10
      A=sscanf(line,[line(1:3) ': %funit1\n']);
      if ~isempty(A)
        fprintf(fid2,'%f\n',A);
      end
    end
end
fclose(fid1)
fclose(fid2)

Answer 2

[KSSV]

str = {'xxx: 0.020000unit1' ; 'yyy: 40.537015180unit2' ;'zzz: 0.021517281unit3'} ;
 x=regexp(str, '.*?(\d+(\.\d+)*)', 'tokens' ) ;

iwant = cellfun( @(x) str2double(x{1}{1}), x )