bessel.3m

<B>Digital的Unix操作系统VAX 4.2源码</B>

.\" SCCSID: @(#)bessel.3m	6.2	8/30/89
.TH bessel 3m VAX
.SH Name
j0, j1, jn, y0, y1, yn \- bessel functions
.SH Syntax
.nf
.B #include <math.h>
.PP
.B double j0(\fIx\fP)
.B double \fIx\fP;
.PP
.B double j1(\fIx\fP)
.B double \fIx\fP;
.PP
.B double jn(\fIn,x\fP)
.B double \fIx\fP;
.PP
.B double y0(\fIx\fP)
.B double \fIx\fP;
.PP
.B double y1(\fIx\fP)
.B double \fIx\fP;
.PP
.B double yn(\fIn,x\fP)
.B double \fIx\fP;
.fi
.SH Description
.NXR "bessel keyword (math)"
.NXR "j0 subroutine"
.NXR "j1 subroutine"
.NXR "jn subroutine"
.NXR "y0 subroutine"
.NXR "y1 subroutine"
.NXR "yn subroutine"
These functions calculate bessel functions of the first
and second kinds for real arguments and integer orders.
.SH Return Values
Negative arguments cause
.PN y0 ,
.PN y1 ,
and
.PN yn
to return \-HUGE_VAL and set
.I errno
to EDOM.
Arguments too large in magnitude cause
.PN j0,
.PN j1,
.PN jn ,
.PN y0,
.PN y1,
and
.PN yn
to return zero and to set
.I errno
to ERANGE.
.SH Environment
When your program is compiled using the System V environment,
nonpositive arguments cause 
.PN y0 ,
.PN y1
and
.PN yn
to return the value HUGE and to set 
.I errno
to EDOM.
In addition, a message indicating DOMAIN error
is printed on the standard error output.
.PP
Arguments too large in magnitude cause
.PN j0,
.PN j1,
.PN y0,
and
.PN y1
to return zero and to set
.I errno
to ERANGE.
In addition, a message indicating TLOSS 
error is printed on the standard error output.
.PP
These error-handling procedures may be changed with the function
.MS matherr 3m .