Demonstrates the solution of an aerospace trajectory optimization problem.
dto_guess(ti, tf, xi, xf, ngrid)
function xg = dto_guess(ti, tf, xi, xf, ngrid)
% compute linear guess
% required by dto_trap.m
% input
% ti = initial time
% tf = final time
% xi = initial state vector component
% xf = final state vector component
% ngrid = number of grid points in guess
% output
% xg = array of initial guesses
% Orbital Mechanics with MATLAB
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% create array of time values at CGL grid points
[t, w] = cgl(ngrid, ti, tf);
% compute slope
xm = (xf - xi) / (tf - ti);
% compute data at grid points
xg(1) = xi;
xg(ngrid) = xf;
for i = 2: ngrid - 1
xg(i) = xm * t(i) + xi;
end