108 lines
1.3 KiB
C++
108 lines
1.3 KiB
C++
//-----------------------------------------------------------------------------
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//
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// Bessel J function
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//
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// Input: tos-2 x (can be a symbol or expr)
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//
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// tos-1 n
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//
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// Output: Result on stack
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//
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//-----------------------------------------------------------------------------
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#include "stdafx.h"
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#include "defs.h"
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static void __besselj(void);
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extern int isnegativeterm(U *);
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void
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eval_besselj(void)
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{
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push(cadr(p1));
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eval();
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push(caddr(p1));
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eval();
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besselj();
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}
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void
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besselj(void)
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{
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save();
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__besselj();
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restore();
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}
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#define X p1
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#define N p2
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void
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__besselj(void)
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{
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double d;
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int n;
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N = pop();
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X = pop();
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if ((X->k == DOUBLE) && (isinteger(N))) {
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push(N);
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n = pop_integer();
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d = jn(n,X->u.d);
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push_double(d);
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return;
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}
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if (isnegativeterm(X)) {
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push(X);
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negate();
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push(N);
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power();
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push(X);
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push(N);
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negate();
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power();
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multiply();
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push_symbol(BESSELJ);
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push(X);
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negate();
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push(N);
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list(3);
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multiply();
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return;
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}
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if (isnegativeterm(N)) {
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push_integer(-1);
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push(N);
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power();
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push_symbol(BESSELJ);
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push(X);
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push(N);
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negate();
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list(3);
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multiply();
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return;
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}
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push_symbol(BESSELJ);
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push(X);
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push(N);
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list(3);
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return;
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}
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static char *s[] = {
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"besselj(x,n)",
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"besselj(x,n)",
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};
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void
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test_besselj(void)
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{
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test(__FILE__, s, sizeof s / sizeof (char *));
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}
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