very simple plotting question EASY PLOT HELP

ok so i am trying to get values from my function and then plot them. am i doing this right? finddata function spits out scalar values for T,P,rho. but my values for T,P,rho continuously change and are not stored in a vector for the variables when i use the debugger i see this. it y,w,z should all end up being a 1x40 array but they are not.

x = 1:10000:400000;

for i = 0:10000:400000
    [T,P,rho] = finddata(i);
    ynew = T;
    y = ynew+1;
    wnew = P;
    w = wnew+1;
    znew = rho;
    z = znew+1;
end

plot(x,y) plot(x,w) plot(x,z)

Answer 1

[Azzi Abdelmalek]

x = 1:10000:400000;
for i = 1:numel(x)
  [T,P,rho] = finddata(x(i));
  y(i) = T+1;
  w(i) = P+1;
  z(i) = rho+1;
end
plot(x,y,x,w,x,z)