Error with noninteger numbers

Problem

I am trying to run the following equation. # 'n' from 0.5 to 3 with step of 0.1 # 'i' from 0.85 to 1 with step 0.05.

After running the M-file. the following error is popping on the screen:

?? Attempted to access m(0.5,0.85); index must be a positive integer or logical.

m = zeros(25,2);

for n = 0.5:0.1:3;

     for i = 0.85:0.05:1.2

     m(n,i) = ((8*i)/(abs(3*n - 1))) - abs(3/n^2)

     end

end

Please help.

Thanks in advance.

Pushkar

Answer 1

[Andrei Bobrov]

m = bsxfun(@(x,y)8*x./abs(3*y-1) - abs(3./y.^2),.85:.05:1.2,(.5:.1:3).');

Answer 2

[Azzi Abdelmalek]

you can't use

    x(0.5) or x(-1)

the index must be a positive integer or logical

m = zeros(25,2);
k1=0;
for n = 0.5:0.1:3;
   k1=k1+1
   k2=0;
   for i = 0.85:0.05:1.2
   k2=k2+1;
   m(k1,k2) = ((8*i)/(abs(3*n - 1))) - abs(3/n^2)
   end
end

Answer 3

[Star Strider]

I suggest this approach:

m = zeros(25,2);

n = 0.5:0.1:3;
i = 0.85:0.05:1.2;
for k1 = 1:length(n)
     for k2 = 1:length(i)     
         m(k1,k2) = ((8*i(k2))./(abs(3*n(k1) - 1))) - abs(3./n(k1)^2);     
     end
end

Answer 4

[Matt J]

[n,i]=ndgrid(0.5:0.1:3,  0.85:0.05:1.2);

m = ((8.*i)./(abs(3.*n - 1))) - abs(3./n.^2);