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17.2.08

Expanding my Horizons With LOGO

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]
END

So if I now if I want to draw a hexagon, I can input

polygon 6

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!!!

2 comments:

Andy Roberts said...

Neat. You've generated a complex optical illusion with just a few characters of code.

Another stage might be to improve on the fixed length of a side.

"polygon 360" should really produce an approximate circle, of similar size to the square "polygon 4" or would it be better to have a second parameter to specify side length?

Daniel said...

Simon, great work on this, you gave me a little inspiration to mimic this using Scratch, details here: http://themasterplan.edublogs.org/archives/29

Regards,

Dan