ATAN(3F)ATAN(3F)NAME
atan, datan, qatan, atand, datand, qatand - FORTRAN arctangent intrinsic
function
SYNOPSIS
real r1, r2
double precision dp1, dp2
real*4 r3, r4
real*8 dp3, dp4
real*16 qp1, qp2, qp3, qp4
r2 = atan(r1)
dp2 = datan(dp1)
dp2 = atan(dp1)
qp2 = qatan(qp1)
qp2 = atan(qp1)
r4 = atand(r3)
dp4 = datand(dp3)
dp4 = atand(dp3)
qp4 = qatand(qp3)
qp4 = qatand(qp3)DESCRIPTION
atan returns the real arctangent of its real argument. datan returns the
double-precision arctangent of its double-precision argument. qatan
returns the real*16 arctangent of its real*16 argument. The generic form
atan may be used with a double-precision argument returning a double-
precision value, or a real*16 argument returning a real*16 value. The
result of atan, datan, and qatan is in radians and is in the range -Pi/2
< result < Pi/2.
atand returns the real*4 arctangent of its real*4 argument. datand
returns the real*8 arctangent of its real*8 argument. qatand returns the
real*16 arctangent of its real*16 argument. The generic form atand may
be used with a real*8 argument returning a real*8 value, or a real*16
argument returning a real*16 value. The result of atand, datand, and
qatand is in degrees and is in the range -90 < result < 90.
SEE ALSOtrig(3M).
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