function $[$coefficient$\_$vector$]=$ func$\_$fit$($X$,$Y$,$type,basis,parameters$)$

if contains$($type$,$ 'approximate'$)$

if contains$($basis$,$'poly'$)$

else

end

e

lse

if contains$($basis$,$'poly'$)$

x$\_$transpose $=$ X$\text{'}$;

result $=$ x$\_$transpose $*$ X;

results $=$ result $\backslash$ x$\_$transpose $*$ Y;

coefficient$\_$vector $=$ results;

return

else

X$\_$trig $=[$sin$($X$),$ cos$($X$)]$;

result$1=$ X$\_$trig' $*$ X$\_$trig;

result$1$s $=$ result$1\backslash ($X$\_$trig' $*$ Y$)$;

coefficient$\_$vector $=$ result$1$s;

return;

end

end

basis is poly or trig, type is approximate or interpolate. need help for approximate.

not vander or polyfit

matlab