How I can select the maximum number in my filename?

I really would appreciate if anyone could solve my problem. I have

   net1_0.2327.mat
      net1_0.3425.mat
      net2_0.8765.mat 
      net2_0.6754.mat ,......to net50_0.87654.mat net50_0.3456.mat

I would like to get these net1_0.3425.mat net2_0.8765.mat ,.... the max of each net1 to net net50(comparing net1 with net1 and net2 with net2 and so on) I used the script

    dinfo = dir('net*.mat');        
        filenames = {dinfo.name};
        parts = regexp(filenames, '_', 'split');
    part2 = cellfun(@(C) C{2}, parts, 'Uniform',0);
    parts3 = regexp(part2, '.mat', 'split');% to remove mat extension
    val2 = str2double(parts3)% I get NaN instead of numbers!

Thanks in advance for your help.

Answer 1

[Walter Roberson]

dinfo = dir('net*.mat');        
filenames = {dinfo.name};
filenumstr = regexprep(filenames, {'^[^_]+_', '\.mat$'}, {'', ''});
val2 = str2double(filenumstr);

Answer 2

[Morteza]

Change your code like below:

      clc,clear all
      dinfo = dir('net*.mat');        
          filenames = {dinfo.name};
          parts = regexp(filenames, '_', 'split');
      part2 = cellfun(@(C) C{2}, parts, 'Uniform',0);
      parts3 = regexp(part2, '.mat', 'split');% to remove mat extension
      for i = 1:length(parts3)
          val2(i) = str2double(cell2mat(parts3{1,i}));
      end

[Rita]

Thank you so much Morteza.