🚀 go-pugleaf

	I need some help and ammunition.

	The system administrators where I work are unwilling to allow
me to install new functions in DATATRIEVE because they claim that this
will degrade the performance of all of DATATRIEVE.  

	There are two functions I want to install:

	arc-cosine	a simple link to RTL.

	great-circ-dist		a function I have written myself to 
				calculate the great circle distance
				between lat - lon points.

	gcd = 60*arccos( sin(lat1)sin(lat2) +
				cos(lat1)cos(lat2)cos(lon1 - lon2) )

	{ lat and lon are calculated:   SIGN*( degrees + minutes/60 )
		SIGN  North = +1; South = -1; West =+1; East =-1;   }

MY QUESTION:  given that the functions are installed correctly, 

1) are links to the RTL expensive?

2) are links to user written functions expensive?

3) there will be a one time disruption of pointers in images that call
	DATATRIEVE at the relinking of DATATRIEVE.  Will future releases
	of VMS {4.0 4.1 etc.} automatically build the new functions in,
	or will that have to be done manually each time?

		Thanks in advance for the help!!

	steve ackroyd
	UC San Diego, and
	Southwest Fisheries Service