add value in array

hi,

I have foldername of image, the name of image is a1.bmp, a2.bmp, b1.bmp, b2.bmp.

I want store in array when a1 & a2.bmp the value is 1, and b1&b2.bmp the value is 2.

Here the illustration :

How can I do it in matlab ? thanks

Answer 1

[KSSV]

files = {'a1.bmp' ; 'a2.bmp' ; 'b1.bmp' ; 'b2.bmp' } ;
N = length(files) ;
iwant = zeros(N,1) ;

letter2number = @(c)1+lower(c)-'a';
for i = 1:N
    [filepath,name,ext] = fileparts(files{i}) ;
    k = letter2number(name) ;
    iwant(i) = k(1) ;
end

[Oman Wisni]

Thanks sir, if the image more than 4 how to declarad it? I mean the name of image not declarad, is automatically show when I input image

[KSSV]

files = dir('*.bmp') ;

This will take all bmp file names.

[Oman Wisni]

Sir, I already trying it, but when I input another image with different name the result before replace. I have 11 species of leaf, every species contain with 25 image. I want to save it without replacing the value. Here I attached the image what I mean and here I have code for it but still error.

try
  load Target.mat
  catch me
end
  if exist('target','var')~=0
  height = size(Input,1);
  else
  %Input = [];
  IDName=[];
  end
  ID = cellstr(foldername); %String
  IDName = [IDName;ID];
  target = zeros(1,275);
  target(1:25,:) = 1;
  target(26:50,:) = 2;
  target(51:75,:) = 3;
  target(76:100,:) = 4;
  target(101:125,:) = 5;
  target(121:150,:) = 6;
  target(151:175,:) = 7;
  target(176:200,:) = 8;
  target(201:225,:) = 9;
  target(226:250,:) = 10;
  target(251:275,:) = 11;

      Targettable.Properties.VariableNames = target;
      save('target.mat','target','targettable','IDName');