import newlib-2000-02-17 snapshot

1 files changed, 248 insertions, 0 deletions

diff --git a/newlib/libm/mathfp/w_jn.c b/newlib/libm/mathfp/w_jn.c
new file mode 100644
index 0000000..6806f01
--- /dev/null
+++ b/newlib/libm/mathfp/w_jn.c
@@ -0,0 +1,248 @@
+
+/* @(#)w_jn.c 5.1 93/09/24 */
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunPro, a Sun Microsystems, Inc. business.
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice 
+ * is preserved.
+ * ====================================================
+ */
+
+/*
+FUNCTION
+<<jN>>,<<jNf>>,<<yN>>,<<yNf>>---Bessel functions
+
+INDEX
+j0
+INDEX
+j0f
+INDEX
+j1
+INDEX
+j1f
+INDEX
+jn
+INDEX
+jnf
+INDEX
+y0
+INDEX
+y0f
+INDEX
+y1
+INDEX
+y1f
+INDEX
+yn
+INDEX
+ynf
+
+ANSI_SYNOPSIS
+#include <math.h>
+double j0(double <[x]>);
+float j0f(float <[x]>);
+double j1(double <[x]>);
+float j1f(float <[x]>);
+double jn(int <[n]>, double <[x]>);
+float jnf(int <[n]>, float <[x]>);
+double y0(double <[x]>);
+float y0f(float <[x]>);
+double y1(double <[x]>);
+float y1f(float <[x]>);
+double yn(int <[n]>, double <[x]>);
+float ynf(int <[n]>, float <[x]>);
+
+TRAD_SYNOPSIS
+#include <math.h>
+
+double j0(<[x]>)
+double <[x]>;
+float j0f(<[x]>)
+float <[x]>;
+double j1(<[x]>)
+double <[x]>;
+float j1f(<[x]>)
+float <[x]>;
+double jn(<[n]>, <[x]>)
+int <[n]>;
+double <[x]>;
+float jnf(<[n]>, <[x]>)
+int <[n]>;
+float <[x]>;
+
+double y0(<[x]>)
+double <[x]>;
+float y0f(<[x]>)
+float <[x]>;
+double y1(<[x]>)
+double <[x]>;
+float y1f(<[x]>)
+float <[x]>;
+double yn(<[n]>, <[x]>)
+int <[n]>;
+double <[x]>;
+float ynf(<[n]>, <[x]>)
+int <[n]>;
+float <[x]>;
+
+DESCRIPTION
+The Bessel functions are a family of functions that solve the
+differential equation
+@ifinfo
+.  2               2    2
+. x  y'' + xy' + (x  - p )y  = 0
+@end ifinfo
+@tex
+$$x^2{d^2y\over dx^2} + x{dy\over dx} + (x^2-p^2)y = 0$$
+@end tex
+These functions have many applications in engineering and physics.
+
+<<jn>> calculates the Bessel function of the first kind of order
+<[n]>.  <<j0>> and <<j1>> are special cases for order 0 and order
+1 respectively.
+
+Similarly, <<yn>> calculates the Bessel function of the second kind of
+order <[n]>, and <<y0>> and <<y1>> are special cases for order 0 and
+1.
+
+<<jnf>>, <<j0f>>, <<j1f>>, <<ynf>>, <<y0f>>, and <<y1f>> perform the
+same calculations, but on <<float>> rather than <<double>> values.
+
+RETURNS
+The value of each Bessel function at <[x]> is returned.
+
+PORTABILITY
+None of the Bessel functions are in ANSI C.
+*/
+
+/*
+ * wrapper jn(int n, double x), yn(int n, double x)
+ * floating point Bessel's function of the 1st and 2nd kind
+ * of order n
+ *          
+ * Special cases:
+ *	y0(0)=y1(0)=yn(n,0) = -inf with division by zero signal;
+ *	y0(-ve)=y1(-ve)=yn(n,-ve) are NaN with invalid signal.
+ * Note 2. About jn(n,x), yn(n,x)
+ *	For n=0, j0(x) is called,
+ *	for n=1, j1(x) is called,
+ *	for n<x, forward recursion us used starting
+ *	from values of j0(x) and j1(x).
+ *	for n>x, a continued fraction approximation to
+ *	j(n,x)/j(n-1,x) is evaluated and then backward
+ *	recursion is used starting from a supposed value
+ *	for j(n,x). The resulting value of j(0,x) is
+ *	compared with the actual value to correct the
+ *	supposed value of j(n,x).
+ *
+ *	yn(n,x) is similar in all respects, except
+ *	that forward recursion is used for all
+ *	values of n>1.
+ *	
+ */
+
+#include "fdlibm.h"
+#include <errno.h>
+
+#ifndef _DOUBLE_IS_32BITS
+
+#ifdef __STDC__
+	double jn(int n, double x)	/* wrapper jn */
+#else
+	double jn(n,x)			/* wrapper jn */
+	double x; int n;
+#endif
+{
+#ifdef _IEEE_LIBM
+	return jn(n,x);
+#else
+	double z;
+	struct exception exc;
+	z = jn(n,x);
+	if(_LIB_VERSION == _IEEE_ || isnan(x) ) return z;
+	if(fabs(x)>X_TLOSS) {
+	    /* jn(|x|>X_TLOSS) */
+            exc.type = TLOSS;
+            exc.name = "jn";
+	    exc.err = 0;
+	    exc.arg1 = n;
+	    exc.arg2 = x;
+            exc.retval = 0.0;
+            if (_LIB_VERSION == _POSIX_)
+                errno = ERANGE;
+            else if (!matherr(&exc)) {
+               errno = ERANGE;
+            }        
+	    if (exc.err != 0)
+	       errno = exc.err;
+            return exc.retval; 
+	} else
+	    return z;
+#endif
+}
+
+#ifdef __STDC__
+	double yn(int n, double x)	/* wrapper yn */
+#else
+	double yn(n,x)			/* wrapper yn */
+	double x; int n;
+#endif
+{
+#ifdef _IEEE_LIBM
+	return yn(n,x);
+#else
+	double z;
+	struct exception exc;
+	z = yn(n,x);
+	if(_LIB_VERSION == _IEEE_ || isnan(x) ) return z;
+        if(x <= 0.0){
+	    /* yn(n,0) = -inf or yn(x<0) = NaN */
+#ifndef HUGE_VAL 
+#define HUGE_VAL inf
+	    double inf = 0.0;
+
+	    SET_HIGH_WORD(inf,0x7ff00000);	/* set inf to infinite */
+#endif
+	    exc.type = DOMAIN;	/* should be SING for IEEE */
+	    exc.name = "yn";
+	    exc.err = 0;
+	    exc.arg1 = n;
+	    exc.arg2 = x;
+	    if (_LIB_VERSION == _SVID_)
+	        exc.retval = -HUGE;
+	    else
+	        exc.retval = -HUGE_VAL;
+	    if (_LIB_VERSION == _POSIX_)
+	        errno = EDOM;
+	    else if (!matherr(&exc)) {
+	        errno = EDOM;
+	    }
+	    if (exc.err != 0)
+	       errno = exc.err;
+            return exc.retval; 
+        }
+	if(x>X_TLOSS) {
+	    /* yn(x>X_TLOSS) */
+            exc.type = TLOSS;
+            exc.name = "yn";
+	    exc.err = 0;
+	    exc.arg1 = n;
+	    exc.arg2 = x;
+            exc.retval = 0.0;
+            if (_LIB_VERSION == _POSIX_)
+                errno = ERANGE;
+            else if (!matherr(&exc)) {
+                errno = ERANGE;
+            }        
+	    if (exc.err != 0)
+	       errno = exc.err;
+            return exc.retval; 
+	} else
+	    return z;
+#endif
+}
+
+#endif /* defined(_DOUBLE_IS_32BITS) */