What does "prep7" mean?

[jgd10]

As I understand it, "prep7" means "preprocesor". But what does the "7" mean? I saw this article which mentions it may be a legacy thing, but does anyone know what it means definitively?

[akaszynski]

Since there's other routines that end with a number (like POST1, AUX2, AUX3, and POST26), I speculate that it's just how these routines were written when MAPDL was created. Probably over time many of these routines were replaced or renamed, but some seem to have stuck.

[jgd10]

I can believe that, though I'd love to know why so many have numbers!

[jgd10]

Like, it's an interesting design choice for a language

[akaszynski]

This likely goes all the way back to the punchcard days. There was probably a reason for it, even if esoteric.

[germa89]

I'm curious about this... pinging @mikerife for possible info about this?

[mikerife]

Hi @germa89 @jgd10 @akaszynski wow you guys are digging into the deep prehistoric past here! I think that between the punch card days and maybe version 4 there were only /auxN commands (where N is a number). /aux6 and /aux7 both did some kind of preprocessing and got wrapped up into /prep7 at some time. For some reason /aux1 did some post processing (starting at the end there) and became /post1.

Entering /aux4 and /aux5 in MAPDL interactive will echo back as being spare routines. Others won't do anything.

I suspect that most analysis types had their own /aux processors. /aux9 used to be for spectrum analyses. /aux11 got put into /solu. Did the sleuthing by running this in MAPDL batch and checking the output.

/NERR,,,-1
*do,i,1,100,1
fini
/aux%i%
*enddo

Anything further would require tracking down John Swanson on a beach somewhere in Florida and asking him.

Mike