Cannot get final output for for loop

soilgray=getimage(handles.axes1);
soilgray=rgb2gray(soilgray);
level=graythresh(soilgray);
im=im2bw(soilgray,level);
axes(handles.axes2);
imshow(im);

cc = bwconncomp(im,8);
n= cc.NumObjects;
set(handles.text11,'String',n);

Area = zeros(n,1);
Diameter = zeros(n,1);
MajorAxis = zeros(n,1);
Clay=zeros(1,n);
Silt=zeros(1,n);
Sand=zeros(1,n);

k = regionprops(cc,'Area','EquivDiameter','MajorAxisLength');

for i=1:n    
    Area(i)      = k(i).Area;
    Diameter(i)  = sqrt(4*[k(i).Area]/pi);
    MajorAxis(i) = k(i).MajorAxisLength;
    Diameter(i) = (Diameter(i)*25.4)/300;
    Diameter(i) = round(Diameter(i),3,'significant');
    if Diameter(i) < 0.002
        Clay(i) = Diameter(i);

      else if Diameter(i) >=0.002 && Diameter(i) < 0.05
              Silt(i) = Diameter(i);

          else if Diameter(i) >= 0.05 && Diameter(i) < 2
                  Sand(i) = Diameter(i);
              end
          end
      end
  end

   NumC = numel(Clay);
               ClayPercentage = (NumC/n)*100;
               set(handles.text15,'String',ClayPercentage);

   NumSi = numel(Silt);
               SiltPercentage = (NumSi/n)*100;
               set(handles.text16,'String',SiltPercentage);

         NumSa = numel(Sand);
               SandPercentage = (NumSa/n)*100;
               set(handles.text17,'String',SandPercentage);

I need help in getting the percentage. Every time I run the program all the text box shows is 100%. It is suppose to show on the Clay or Silt or Sand percentage not all the n value.

Answer 1

[Image Analyst]

Perhaps the "else if" is messing it up - treating it like two separate statements. Use "elseif" like you're supposed to and see if that works.

Please fix the indenting also. It's very hard to read right now, even after I somewhat fixed the formatting.

Answer 2

[Image Analyst]

Since you assign Clay in the loop and the loop executes n time, then numel(Clay) will be n, and numel(Clay)/1*100 will be 100 always.

You should not add up diameters to get area fraction or number fraction anyway. You need something like

numClayParticles = numClayParticles + 1;

[Tinna Armasamy]

Hi, Thank you for the help. I have made the following changes but there is still a problem.

Area = zeros(n,1); Diameter = zeros(n,1); MajorAxis = zeros(n,1);

k = regionprops(cc,'Area','EquivDiameter','MajorAxisLength'); numClayParticles = 0; numSiltParticles = 0; numSandParticles = 0;

for i=1:n

    Area(i)      = k(i).Area;
    Diameter(i)  = sqrt(4*[k(i).Area]/pi);
    MajorAxis(i) = k(i).MajorAxisLength;

    if      Diameter(i) < 0.002
            numClayParticles = numClayParticles + 1;

    elseif  Diameter(i) >=0.002 && Diameter(i) < 0.05
            numSiltParticles = numSiltParticles + 1;

    elseif  Diameter(i) >= 0.05 && Diameter(i) < 2
            numSandParticles = numSandParticles + 1;

            end
end     

                ClayPercentage = (numClayParticles/n)*100;
                set(handles.text15,'String',ClayPercentage);

                SiltPercentage = (numSiltParticles/n)*100;
                set(handles.text16,'String',SiltPercentage);

                SandPercentage = (numSandParticles/n)*100;
                set(handles.text17,'String',SandPercentage);

The results is showing for SandPercentage only. The ClayPercentage and SiltPercentage is still zero. It is like it skips the if else of clay and silt and only perform sand if else.