Thanks to Andy Roberts for his comment a couple of weeks ago on my post Logo Routines: Building Polygons, where he said,
"To differentiate for the top stream it should be possible to teach the concept of parameter substitution so the challenge would be to write a procedure called Polygon which draws one of any number of sides depending on the number passed across. Most class teachers will stop before getting to this stage, which is a shame because for those who 'get it' a whole new world of constructionism opens up.
I have to admit to being one of those class teachers who never got to this stage, so having had a browse around and a bit of a play, here is my first LOGO procedure using parameter substitution routine, is that the right term Andy?!* It is for drawing a polygon of x number of sides as suggested:
To polygon :SIDES
REPEAT :SIDES [FD 100 RT 360/:SIDES]
So if I now if I want to draw a hexagon, I can input
The procedure, substitutes sides with the number six, and calculates the turn size, by dividing 360, by the number of sides I want the shape to have.
If I now input
repeat 6 [polygon 6 rt 60]
I can create a pattern like this..I guess my next adventure will be to create a "pattern" procedure or write a program that will allow me to substitute not only the :side parameter in the polygon procedure, but also to include a series of turns to output my pattern drawing on the polygon procedure. Mmmm! Looks like I am all set for a bit of a personal engagement to expand my LOGO programming. Will have a crack at this while preparing my unit of work with the Probot for my students. Maybe you can teach an old dog new tricks!!!