SLA_DBJIN

Decode String to B/J Epoch (DP)

ACTION:
Decode a character string into a DOUBLE PRECISION number, with special provision for Besselian and Julian epochs. The string syntax is as for sla_DFLTIN, prefixed by an optional ‘B’ or ‘J’.
CALL:
CALL sla_DBJIN (STRING, NSTRT, DRESLT, J1, J2)
GIVEN:

STRING

C

string containing field to be decoded

NSTRT

I

pointer to first character of field in string


RETURNED:

NSTRT

I

incremented past the decoded field

DRESLT

D

result

J1

I

DFLTIN status:

−1 = −OK

  0 = +OK

  1 = null field

  2 = error

J2

I

syntax flag:

  0 = normal DFLTIN syntax

  1 = ‘B’ or ‘b’

  2 = ‘J’ or ‘j’


NOTES:
(1)
The purpose of the syntax extensions is to help cope with mixed FK4 and FK5 data, allowing fields such as ‘B1950’ or ‘J2000’ to be decoded.
(2)
In addition to the syntax accepted by sla_DFLTIN, the following two extensions are recognized by sla_DBJIN:
(a)
A valid non-null field preceded by the character ‘B’ (or ‘b’) is accepted.
(b)
A valid non-null field preceded by the character ‘J’ (or ‘j’) is accepted.
(3)
The calling program is told of the ‘B’ or ‘J’ through an supplementary status argument. The rest of the arguments are as for sla_DFLTIN.