unit Unit2;
interface
uses
unit1;
procedure CHEBFT(A, B:real; var C:array of real; N:integer);
procedure CHEBPC(C:array of real;var D:array of real; N:integer);
implementation
procedure CHEBFT(A, B:real; var C:array of real; N:integer);
var
K,J:integer; SUM,Y,BMA,BPA,FAC:real;
F:array[0..50] of real;
const
NMAX = 50; PI = 3.14159265358979;
begin
BMA:=0.5 * (B - A);
BPA:=0.5 * (B + A);
For K:=1 To N do
begin
Y:=Cos(PI * (K - 0.5) / N);
F[K]:=FUNC(Y * BMA + BPA);
end;
FAC:=2/ N;
For J:=1 To N do
begin
Sum:=0 ;
For K:=1 To N do
begin
Sum:=Sum + F[K] * Cos((PI * (J - 1)) * ((K - 0.5) / N));
end;
C[J]:=FAC * Sum;
end;
end;
procedure CHEBPC(C:array of real;var D:array of real; N:integer);
var
DD:array[0..50] of real; J,K:integer;
SV:real;
begin
For J:=1 To N do
begin
D[J]:=0 ;
DD[J]:=0;
end;
D[1]:=C[N];
For J:=N - 1 DownTo 2 do
begin
For K:=N - J + 1 DownTo 2 do
begin
SV:=D[K];
D[K]:=2* D[K - 1] - DD[K];
DD[K]:=SV;
end;
SV:=D[1];
D[1]:=-DD[1] + C[J];
DD[1]:=SV;
end;
For J:=N DownTo 2 do
D[J]:=D[J - 1] - DD[J];
D[1]:=-DD[1] + 0.5 * C[1];
end;
end.
