MATLAB: Simple “While Loop” questions

simple "while loop"

Can anyone tell me why this while loop doesn't give me what I want? I want to get simple values such that starting from 0.001 to 0.01 with increment 0.001,0.01 to 0.1 with increment of 0.01,0.1 to 1 with increment 0.1, and 1 to 10 with increment 1. Second question of mine, when I have vsl ==0.1, why it doesn't go into the if loop? What am doing wrong? Thank you!
%% Calculate the gas fraction vsl = 0.001; vsl1 = vsl; vslSave = [];
while vsl<=10
    if vsl >=0.001 && vsl<=0.01
       increment                 = 0.001;
    elseif vsl >=0.01 && vsl< 0.1
       increment                 = 0.01;
    elseif vsl >=0.1 && vsl<=1.0
       increment                 = 0.1;
    else
       increment                 = 1;
    end
    if (vsl==0.1)
        increment                = 0.1;
    end
    vsl                          = vsl + increment;
    vslSave                      = [vslSave;vsl];
end
vslSave                          = [vsl1;vslSave];

Best Answer

vsl will never equal 0.1. See the FAQ: http://matlab.wikia.com/wiki/FAQ#Why_is_0.3_-_0.2_-_0.1_.28or_similar.29_not_equal_to_zero.3F And you don't need all those double ranges - checking if it's in the middle. Just check if it's less than the number - it will go into the first one it meets the criteria for.
% Calculate the gas fraction
vsl = 0.001; 
vsl1 = vsl; 
vslSave = [];
while vsl<=10
  if vsl < 0.01
    increment = 0.001;
  elseif vsl < 0.1
    increment = 0.01;
  elseif vsl < 1.0
    increment  = 0.1;
  else
    increment = 1;
  end
  
  vsl = vsl + increment;
  vslSave = [vslSave;vsl];
end
vslSave = [vsl1;vslSave]
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