Help optimizing/vectorizing a code in which loops are used to fill several vectors

Hello,

I'm trying to fill in several vectors from the info that I have on a text file. I load the different columns of that file o severall Arrays A, B, C, D, E, F, and G.

The size of my vectors is quite big, (10^6 or 10^7) elements so the code I show next takes a long time to run.

Can someone help me with a vectorization of this in order to make it faster?

 [A,B,C,D,E,F,G] = textread(strcat(PathName,FileName),'%f %d %d %d %d %s %s');

n=size(A,1);

for i=1:n   

      if C(i) == 0 && D(i) == 0
          prim(i)=A(i);

      elseif C(i)==0 && D(i) ~= 0
          sc(i)=A(i);

      elseif C(i)~=0 && C(i) ==0
          sc2(i)=A(i);
      end

      if C(i)+D(i)==1
          o1(i)=A(i);

      elseif C(i)+D(i)==2
          o2(i)=A(i);

      elseif C(i)+D(i)==3
          o3(i)=A(i);

      elseif C(i)+D(i)==4
          o4(i)=A(i);    

      elseif C(i)+D(i)>4
         osup(i)=A(i);   
      end
  end

[Kevin Holst]

I haven't looked into your code too much but I believe this line is incorrect anyways:

elseif C(i)~=0 && C(i) ==0

shouldn't it be:

elseif C(i)~=0 && D(i) ==0

Answer 1

[John Petersen]

Here's one way to do it

sc = []; 
i = (~C & D);
sc(i) = A(i);

o3 = zeros(n,1);
CpD = C + D;
i3 = find(CpD ==3);
i4 = find(CpD ==4);
o3(i3) = A(i3); 
o4(i4) = A(i4);

Follow similar logic for the rest of your code.

[Oleg Komarov]

No need for find.

Answer 2

[carlos Uribe]

Thanks very much for taking a look at this...worked like a charm