Comparing rows of a matrix with some row vectors

Question

I have run this program for five hours and it has not yet completed. I wonder if we can make changes to reduce the computation time.

I use several for loop and this greatly increases the computation time. my goal is to compare the contents of the rows of a matrix (4435 ×ばつ 2000) with 6 row vectors (1 ×ばつ 2000). The comparison is made on parts of 64 values.

for i=1:4435 
 for j=70:2000 
 L = A(i,j); 
 j1=0; 
 j2=0; 
 j3=0; 
 j4=0; 
 j5=0; 
 j6=0; 
 for i1=70:2000 
 if D1(B(v,1),i1)==L 
 j1=i1; 
 Break 
 end 
 end
 for i2=1:2000
 if A(B(v-1,1),i2)==L
 j2=i2;
 Break
 end
 end
 for i3=1:2000
 if A(B(v-2,1),i3)==L
 j3=i3;
 Break
 end
 end
 for i4=1:2000
 if A(C(mm,1),i4)==L
 j4=i4;
 Break
 end
 end
 for i5=1:2000
 if A(C(mm-1,1),i5)==L
 j5=i5;
 Break
 end
 end
 for i6=1:2000
 if A(C(mm-2,1),i6)==L
 j6=i6;
 Break
 end
 end
 if j1>64 
 if A(i,j-63:j)==A(B(v,1),j1-63:j1)
 m_A1(i,j)=1;
 else
 m_A1(i,j)=0;
 end
 end 
 if j2>64 
 if A(i,j-63:j)==A(B(v-1,1),j2-63:j2)
 m_A2(i,j)=1;
 else
 m_A2(i,j)=0;
 end
 end 
 if j3>64 
 if A(i,j-63:j)==A(B(v-2,1),j3-63:j3)
 m_A3(i,j)=1;
 else
 m_A3(i,j)=0;
 end
 end 
 if j4>64 
 if A(i,j-63:j)==A(C(mm,1),j4-63:j4)
 m_A4(i,j)=1;
 else
 m_A4(i,j)=0;
 end
 end 
 if j5>64 
 if A(i,j-63:j)==A(C(mm-1,1),j5-63:j5)
 m_A5(i,j)=1;
 else
 m_A5(i,j)=0;
 end
 end 
 if j6>64 
 if A(i,j-63:j)==A(C(mm-2,1),j6-63:j6)
 m_A6(i,j)=1;
 else
 m_A6(i,j)=0;
 end
 end 
 end
end

Answer 1

In Matlab, unlike C, you have to vectorize your code. A first step would be to understand how to use find like this:

i1=70:2000;
j1=find(D1(B(v,1),i1)==L);

and:

if j1>64 
 m_A1(i,j) = all( A(i,j-63:j)==A(B(v,1),j1-63:j1) );
end 

You may also find any and all useful. Eventually you should be able to eliminate all the for loops and if statements.

• user319336: thank you for your answer, but could you, please, also change the part of the program: if j1>64 if A(i,j-63:j)==A(B(v,1),j1-63:j1) m_A1(i,j)=1; else m_A1(i,j)=0; end end
• cyborg: Here you go. See the update.