How to calculate values at the nodal points?

hi!

Need to evaluate certain values at every nodal point. Have discretized then have used for loop to do calculation. Not getting any error but there is a variation in the result. My need is the value of P1,P2 ..... etc must be evaluated at each point. Do x_bar(j) represent the value of x_bar at the j th position (like x_bar(1)=0,x_bar(1)=0.01etc).

Xb = [0, .5, 1.25, 1.50];
delx_bar = [.01, .005, .0001];
x_bar = cumsum([Xb(1), repelem(delx_bar,diff(Xb)./delx_bar)]);
del_eta=0.02;
eta_inf=4;
n_xbar=length(x_bar);
eta=(0:del_eta:eta_inf).';
n_eta=length(eta);
for j=2:n_xbar-1
 for i=2:n_eta
P1(j) = 1 - cos(x_bar(j));
P2(j) = 1 + cos(x_bar(j));
 end
end

[Walter Roberson]

What is the purpose of your "for i=2:n_eta" loop? You do not use "i" inside the loop.

[revathy M]

Have just given the part of the code.i runs over the row and j runs over the column.

Answer 1

[KSSV]

Xb = [0, .5, 1.25, 1.50];
delx_bar = [.01, .005, .0001];
x_bar = cumsum([Xb(1), repelem(delx_bar,diff(Xb)./delx_bar)]);
del_eta=0.02;
eta_inf=4;
n_xbar=length(x_bar);
eta=(0:del_eta:eta_inf).';
n_eta=length(eta);
P1 = zeros([],[]) ;
P2 = zeros([],[]) ;
for j=2:n_xbar-1
    for i=2:n_eta
        P1(i,j) = 1 - cos(x_bar(j));
        P2(i,j) = 1 + cos(x_bar(j));
    end
end

Answer 2

[AM]

Hi, I need a help for my diploma work, can anyone help me to write my matlab code, it's so important.