#
# Numerical Mathematics and Computing, Fifth Edition
# Ward Cheney & David Kincaid
# Brooks/Cole Publ. Co.
# (c) 2003
#
# file:  ctrl_pt_curve
#
# Generating a curve using 7 control points

 n := 6;
 phi := (n,i,t) -> binomial(n,i)*(t**i)*((1-t)**(n-i));
 P := matrix([[1,2,4,3,5,4,1], [1,4,5,3,2,1,1]]);
 f := proc(n::integer, k::integer,t) local i, x, f;
 x := 0.0;
 for i from 0 to n do 
     x := x + P[k,i+1]*phi(n,i,t);
 end do;
 f := x
 end;
 plot1 := plot([f(n,1,t),f(n,2,t), t = 0..1], scaling=constrained);
 pts := [[1,1],[2,4],[4,5],[3,3],[5,2],[4,1],[1,1]];
 plot2 := plot(pts, style=point, symbol=diamond);
 plots[display]({plot1,plot2});