Error in dolphchebyshev array

% Function Called: planar_dolphcheby
%
N = 8;
M = 8;
RdB = 20;
dx = 0.5;
dy = 0.5;
steer_theta = 20;
steer_phi = 40;
steer_ux = sin((steer_theta/180)*pi)*cos((steer_phi/180)*pi)
steer_uy = sin((steer_theta/180)*pi)*sin((steer_phi/180)*pi)
null_theta = 80;
null_phi = -30;
null_ux = sin((null_theta/180)*pi)*cos((null_phi/180)*pi)
null_uy = sin((null_theta/180)*pi)*sin((null_phi/180)*pi)
% Finding the Dolph-Chebyshev weight matrix for the array
w = planar_dolphcheby(dx, dy, N, M, RdB); *_ERROR HERE!!!_*
wd = w(:);
% Defining the Null constraint
null_ux2 = null_ux-steer_ux;
null_uy2 = null_uy-steer_uy;
m = (1:M)';
C = exp(j*pi.*((m*null_ux2)+null_uy2));
for n = 2:N
C = [C; exp(j*pi.*(m*null_ux2+n*null_uy2))];
end
% Finding the optimum weighting in presence of null (4.78)
wo = wd-(wd'*C*inv(C'*C)*C')';
% Applying the optimum weights and steering the main beam
ux_grid = -1:0.02:1;
uy_grid = -1:0.02:1;
for x = 1:length(ux_grid)
ux = ux_grid(x);
for y = 1:length(uy_grid)
uy = uy_grid(y);
B(x, y) = 0;
for m = 1:M
for n = 1:N
B(x, y) = B(x, y)+wo((n-1)*N+m)*exp(-j*2*pi*(m*ux*dx+n*...
uy*dy))*exp(j*2*pi*(m*steer_ux*dx+n*steer_uy*dy));
end
end
end
end
B = abs(B)/max(max(abs(B)));
grid on
surf(ux_grid, uy_grid, (20*log10(B))');
axis([-1 1 -1 1 -70 0])

when i run this program, i hv an error.

??? Undefined function or method 'planar_dolphcheby' for input arguments of type
'double'.

Error in ==> planardolphcheby at 17
w = planar_dolphcheby(dx, dy, N, M, RdB);

I dont really understand what this error means. How do I rectify this problem?

Answer 1

[Wayne King]

Where is the function planar_dolphcheby defined?

You must have an M-file called planar_dolphcheby.m somewhere on your path that has the function definition and the code for that function.