how to populate the left side with the same values as the right side in an array

Hello All,

I want to write a small code that, given an array with an n number of odd cells, populates the left side with the same values as the right side (already populated), and the center cell remains unchanged. I developed the following code:

 for k=drange(1:n/2+0.5) 

 w(k)=input('please input half of the values')
end 
p = randi(10,10,1);                     % Create Data
w = randi(10,10,1);                     % Create Data
[x L E I] = deal(3, 5, 7, 13);          % Create Data
P(j)=-w(j)/(x*(15*x-37*L^2)*(76*H*Y))
q==0   
for j=drange(n/2+1.5:n)
    q=q+1
    P(j)=P(n/2-0.5-q)
end

However, I keep obtaining different errors when I run this script. The most common is:

Index exceeds matrix dimensions.

Error in matlab_codigo (line 11) P(j)==P(n/2-0.5-q)

But other errors also occur. It depends of the inputs I give to the program.

Any help appreciated. Thanks

regards, Hugo

Answer 1

[Image Analyst]

Instead of doing things like n/2+0.5, use ceil(n/2). ceil() goes to the next higher integer. There is also a floor() function to go down (chop off the fraction), and a fix() which goes either way but always towards 0.

Answer 2

[Roger Stafford]

   t = 1:floor(n/2);
   P(:,t) = P(:,n+1-t);

[Hugo]

Tryed this solution but obtained the error index exceed matrix dimensions. Any other suggestion?

[Image Analyst]

What does drange() do? That's not in base MATLAB.

[Roger Stafford]

Try this, Hugo:

   P = rand(7,5); % <-- Choose any sizes you please

   n = size(P,2);
   disp(P)
   t = 1:floor(n/2);
   P(:,t) = P(:,n+1-t);
   disp(P)