Is it possible to store the values at the grid points?if it is how?

Hi! I just have little knowledge on matlab.With what i know I'm just trying to write a code for solving a Block triagonal matrix whose entries are in terms of finite differences.The unknowns has to be found at each grid point.I need to intialize the values at each grid points and have to use the previous grid point value to calculate the unknowns. This is what i have written

%%the intial profiles
deleta=0.2;
for eta=0:deleta:etainf
    f_int= fw +((eta)^2)/(2*etainf);
    F_int =eta/etainf;
    G_int =1-(eta/etainf);
    f(:,1)=f_int;
    F(:,1)=F_int;
    G(:,1)=G_int;
    fxbar(1,1)=f(1,1)/delxbar;
    Fxbar(1,1)=F(1,1)/delxbar;
    Gxbar(1,1)=G(1,1)/delxbar;
    Feta(1,1)=F(1,1)/(2*deleta);
end

%%set Boundary condition
F(1,:)=0;               %%the value at eta =0
G(1,:)=Gw;              %%the value at eta =0
F(:,etainf)=1;          %%the value at etainf
G(:,etainf)=1;          %%the value at etainf
%%March in the xbar direction
for i =2:L
  %%March in the eta direction
  for j=2:H
    fxbar=(f(i,j)-f(i-1,j))/delxbar;
    Fxbar_old=(F(i,j)-F((i-1),j))/delxbar;
    Feta_old=(F(i,j+1))-(F(i,j-1))/(2*deleta);
    Gxbar_old=(G(i,j)-G(i-1,j))/delxbar;
  end 
end

But this doesn't help me. Can anyone guide me how to proceed?

[dpb]

Not able to follow what it is you're trying to build from the nonworking code altho 'tis good to post efforts.

We need a description of the array you need to build first to be able to envision what need to write.

But, yes, you must store the values of the mesh at the integer-valued meshes and work indirectly; there is no such thing as an index being a noninteger. This is kinda hard to grasp how to work with for beginners, granted.

Things like

doc blkdiag   % and friends
doc meshgrid  % may help here, too...

[revathy M]

Hi! I'm working on a fluid mechanics problem.Considered a grid in my region of study.I'm calculating the velocity and temperature profiles at each grid point.Some initial assumptions have been made and has to be calculated and stored at the grid point.Using these values i need to calculate the remaining values at the grid point. My guess is the value at the grid point has to be stored as an array.That's what I've tried. I need to store the value as at f(1,1) =the value obtained at eta =0.At f(2,1)the value obtained at eta=eta+deleta and so on. How do i map the grid points with the array?

Revathy

[KSSV]

There are many value sin the code which are not defined...give the complete code. It can be made to work.