48: Moving average with DOSUBS

[Dave Britten]

I need to whip up a quick moving-average program. This doesn't work:

Code:

AVG:
\<< DUP \GSLIST SWAP SIZE / \>>

MAVG:
\<< \-> L N
  \<< L N \<< N \->LIST AVG \>> DOSUBS \>>
\>>

And it's fairly obvious why: DOSUBS doesn't like the local name 'N' being present in the program it's being passed.

What's the trick to modifying a program on the stack? I figure I should be able to recall the value of N, prepend it to \<< ->LIST AVG \>>, and have a program that DOSUBS will take. You can't simply concatenate programs with +, and while it works with lists, DOSUBS won't accept the function stored as a list.