24 lines
610 B
Text
24 lines
610 B
Text
include c:\cxpl\stdlib;
|
|
|
|
func real NRoot(A, N, Prec); \Return the Nth root of A with precision Prec
|
|
real A;
|
|
int N;
|
|
real Prec;
|
|
real X, X0, Y, NF;
|
|
int I;
|
|
[NF:= float(N);
|
|
X:= 1.0; \initial guess
|
|
repeat X0:= X;
|
|
Y:= 1.0;
|
|
for I:= 1 to N-1 do Y:= Y*X0;
|
|
X:= ((NF-1.0)*X0 + A/Y) / NF;
|
|
until abs(X-X0) < Prec; \(until X=X0 doesn't always work)
|
|
return X;
|
|
];
|
|
|
|
[Format(5, 15);
|
|
RlOut(0, NRoot( 2., 2, 1.0E-15)); CrLf(0);
|
|
RlOut(0, Power( 2., 0.5)); CrLf(0); \for comparison
|
|
RlOut(0, NRoot(27., 3, 1.0E-15)); CrLf(0);
|
|
RlOut(0, NRoot(1024., 10, 1.0E-15)); CrLf(0);
|
|
]
|