How to create a matrix using conditional statements in a loop based in another matrix

Hello,

I have a matrix and I want to generate another matrix according to their elements using a loop.

If one ore more elements of a row is ==0 the correspondent row in the new matrix need to be 0.

If not, it needs to be the sum of the elements in the row.

Comb =                                        % The initial matrix 
            0            0
        4.303            0
         2.68            0
            0        1.705
        4.303        1.705
         2.68        1.705
         
         
         
  % I need this output: 
  H = [0
       0
       0
       0
       6.008
       4.385]
      
      
  

I started with this loop:

       
for i = 1:size(Comb, 1)
        for j = 1:size(Comb, 2)
            
              x = (sum(Comb'))'
           
              if abs(Comb(i,j)) == 0
             
             
             end
        end
      
end

But it gives that:

x =

0

4.303

2.68

1.705

6.008

4.385

I do not know what insert on the if to display zeros when one element of the row is equal to zero.

Could you help me ?

Thans in advance !

Answer 1

[Andrei Bobrov]

H = all(Comb,2).*sum(Comb,2);

[Rachel Sabioni]

Hello Andrei,

Thak you so much. It worked !

Answer 2

[madhan ravi]

H=zeros(size(Comb,1),1);
idx=any(Comb,2);
H(idx)=sum(Comb(idx,:),2)

[Rachel Sabioni]

Hi Madhan,

Thank you for your response.

I am still have troubles. When I insert your code it keeps showing the same of before:

>> H=zeros(size(Comb,1),1);

idx=any(Comb,2);

H(idx)=sum(Comb(idx,:),2)

H =

0

4.303

2.68

1.705

6.008

4.385

If there is zero on the first or second column of Comb matrix, I need that the result of H is = 0.

Do you know how to deal with that ?

[madhan ravi]

I have no idea why you get the result, I got the result as your expected output. Try

clear all 

at the beginning and try again just try the answer I gave.

[madhan ravi]

Ah messed up with any() , use

all(Comb,2)

[Rachel Sabioni]

Thank you so much Madhan. Now it worked ! =)

Answer 3

[Joel Newton]

Hi, i wish to make a new matrix from the one below such that if the difference between elements in the second and third row is plus or minus 2 return a value of the mid point in each element of the new matrix. if the difrrence is more than 2 then keep the values from the old matrix in the new matrix.

orginal data =

1 1 1 1

10 10 10 9

14 11 14 11

new matrix should look like this =

1 1 1 1

10 10.5 10 10

14 10.5 14 10

my data set has multiple rows of this 3 block of values (if that makes sense), how do I then iterate down for the rest of the data?

Thanks!

[Andrei Bobrov]

Hi Joel! Please ask your question through the menu tab ('Ask' tab).