[Squeakland] Weird Heading numbers

[Mike Stramba]

Compasses, GPS, Aircraft, Marine Vessels all use "real headings".

I've never heard of any other use for them (before playing with Etoys ;)  )

Mike


>From: Paulo Drummond <ptdrumm at terra.com.br>
>To: mstram <mstramba at sympatico.ca>
>CC: squeakland at squeakland.org
>Subject: Re: [Squeakland] Weird Heading numbers
>Date: Fri, 25 May 2007 23:50:47 -0300
>
>Imho, there is no such thing as "real headings". Geometry, as its  mother 
>Mathematics is a wonderful symbolical language to provide us  all means of 
>mapping the physical world as we see it.
>
>The use of semi-circular geometrical convention helps (among other  things) 
>in:
>1) give the sense of "negative" when the object passes "downward" or  "to 
>the other side" of an 2-D axis (another convention);
>2) the coming back rationally to zero instead of jumping from  359º59'59" 
>to it.
>
>cheers,
>Paulo
>
>On May 25, 2007, at 7:19 PM, mstram wrote:
>
>>
>>While playing with the Etoys, I've noticed the "weird" heading  numbers.
>>
>>By that I mean when the object's heading passes 180 degrees,  instead of
>>continuing on to 190 ... 270 .. 360, we get the negative numbers.
>>
>>Why was this convention adopted ?
>>
>>I think if kids ... and some us "older" kids are going to be using  
>>headings
>>it would be more educational and instructive to use "real" headings.
>>
>>Maybe an option / preference could be setup on which heading numbering
>>system to use.
>>
>>The only minor problem I can see is whether it should be "0" or  "360" to
>>begin with.
>>
>>Just for the fun of it, I'm digging in and seeing if I can  construct my 
>>own
>>subclass to use the "360" system.   I have an idea for an ATC  simulation 
>>I'd
>>like to do and "real" headings .. or at least converted for input  and 
>>output
>>would be a must.
>>
>>Mike
>>--
>>View this message in context: http://www.nabble.com/Weird-Heading- 
>>numbers-tf3818581.html#a10811065
>>Sent from the SqueakLand mailing list archive at Nabble.com.
>>
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