Evaluate Chebyshev polynomial
y=chebyshev_eval(x,n)
a matrix of doubles
a 1-by-1 matrix of doubles, integer value, n>=0.
a matrix of doubles, the function value
Evaluates a Chebyshev polynomial of degree n at point x.
The first Chebyshev polynomials are
The remaining Chebyshev polynomials satisfy the recurrence:
for n=1,2,...
x=linspace(-1,1,100); y0=chebyshev_eval(x,0); y1=chebyshev_eval(x,1); y2=chebyshev_eval(x,2); y3=chebyshev_eval(x,3); h=scf(); plot(x,y0,"r-") plot(x,y1,"g-") plot(x,y2,"b-") plot(x,y3,"c:") xtitle("Chebyshev Polynomials","x","T(x)") legend(["n=0","n=1","n=2","n=3"]); h.children.data_bounds(1:2,2)=[-1.1;1.1]; h.children.children(4).children.thickness=3; h.children.children(5).children.thickness=2; h.children.children(5).children.line_style=5; | ![]() | ![]() |