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+--- Thread: Program NEWT2 (/thread-10348.html)
Program NEWT2 - KarelPostulart - 03-19-2018 02:58 PM
Hi,
The program below is to my opinion an improved working variation on the program provided by Han. The original version led to an error message.
Original version
EXPORT NEWT2()
BEGIN LOCAL n, xold, xnew, err, N, f;
N := 100; err := .00001; xnew := 1;
IF INPUT(
{f, xnew, err, N},
"Newton's Method",
{"f(X) = ", "Guess = ", "Error = ", "Max Iter. = "},
{
"Enter the function surrounded by single quotes",
"Enter the initial guess",
"Enter the tolerance",
"Enter the maximum number of iterations"
},
{f, xnew, err, N}
) THEN F1 := f;
CAS("F0 := id-F1/F1'");
L1 := {}; L1(1) := xnew;
FOR n FROM 2 TO N+1 DO xold := xnew;
xnew := F0(xold);
L1(n) := xnew;
IF ABS(xnew-xold) < err THEN break; END;
END;
EDITLIST(L1);
END;
Improved version
EXPORT NEWT2
BEGIN
LOCAL n, xold, xnew, err, N, f;
N := 100; err := .00001; xnew := 1;
f:='X';
// By defining f as'X' as a default value
// the program works
IF INPUT(
{f, xnew, err, N},
"Newton's Method",
{"f(X) = ", "Guess = ", "Error = ", "Max Iter. = "},
{
"Enter the function surrounded by single quotes",
"Enter the initial guess",
"Enter the tolerance",
"Enter the maximum number of iterations"
},
{f, xnew, err, N}
) THEN F1 := f;
CAS("F0 := id-F1/F1'");
L1 := {}; L1(1) := xnew;
FOR n FROM 2 TO N+1 DO xold := xnew;
xnew := F0(xold);
L1(n) := xnew;
IF ABS(xnew-xold) < err THEN break; END;
END;
EDITLIST(L1);
END;
END;