str1 = '@5%';
str2 = '@2.5%';
regex = '\d*\.?\d+';
[s1 e1] = regexp(str1, regex);
[s2 e2] = regexp(str2, regex);
str1(s1:e1)
str2(s2:e2)
>> ans =
5
>> ans =
2.5
Play around with this. The regex captures 0 or more digits, 0 or 1 dots, and one or more digit. It ignores the @ and % signs. There are possibly weird cases where it may not work.
