Re: Heading issue

["Daniel Ajoy" <da.ajoy@xxxxxxxxx>]

On 29 Jul 2007 at 14:45, Boyd, Ronald wrote:

> This is a project from one of my students from this past 
> week. His page polygon-or-non was a bit of a stretch for 
> the intention of the project and so went unfinished at the 
> end of the week show. Our problem was in trying to write a 
> procedure that would sense the heading of the turtle 
> respond correclty to the users choice of polygon or non 
> polygon. Luckily he choose to draw the non-polygon shapes 
> next to each other which should have made it easier. Our 
> first attempt is in the turtles note section. We tried 
> having two buttons that would elicit either a correct or a 
> incorrect response based on sensing if the turtles heading 
> fell within a parameter using the ifelse. 

the code was:

to non-polygon  
jag,
ifelse {heading > 284 and heading < 85} [correct][wrong]
end

to polygonshape 
jag,
ifelse {heading < 285 and heading > 85} [correct][wrong]
end

to correct
announce [correct]
end

to wrong
announce [Try again]
end


but "and" is like any other procedure in MicroWorlds
it receives two inputs, that should be truth values.

The right syntax is:

ifelse and (heading > 284) (heading < 85) [correct][wrong]

or simply

ifelse and heading > 284 heading < 85 [correct][wrong]



I've never seen curly brackets used in MicroWorlds:


Daniel
OpenWorld Learning