Matlab编辑文本文件，用数字替换数字

Question

I want to use Matlab to replace every floating point number in a text file with another number. (let's say half the original value) Other data (integer and string) should not change. A few lines of my text file (each variable is in a new line):

VERTEX
  8
0
 10
0.000000
 20
110.500000
 42
0.000000
  0
VERTEX
  8
0
 10
0.000000
 20
0.000000
 42
0.000000
  0
VERTEX
  8
0
 10
124.000000
 20
0.000000
 42
0.000000
  0
VERTEX
  8
0
 10
248.000000
 20
0.000000
 42
0.000000
  0
VERTEX
  8
0
 10
248.000000
 20
110.500000
 42
0.000000
  0
VERTEX
  8
0
 10
248.000000
 20
221.000000
 42
0.000000
  0

Any help is appreciated.

Answer 1

Here is a solution using fgetl and regexp

rid = fopen('test.txt','r');
wid = fopen('test2.txt','w');

while ~feof(rid)    
    s = fgetl(rid); % read a line
    if regexp(s, '\d+\.\d+') % float founded
        fprintf(wid, '42\n'); % wite "another integer"
    else
         fprintf(wid, '%s\n', s); % write original data
    end

end

fclose(rid);
fclose(wid);