Re: [NTG-context] question about MP drawing with dir

On 05/24/2018 10:23 PM, Alan Braslau wrote:

On Thu, 24 May 2018 21:01:59 +0200 Pablo Rodriguez wrote:

...

dir seems magic to me. I don’t understand how it works, not even how it can be used for drawing not having an origin.

All MP drawings have an origin (0,0).

I thought origin had to be explicitly set.

(dir angle) returns a pair on a unit circle surrounding the origin, i.e. (cosd angle,sind angle) where cosd is the cosine function operating on an angle in degrees.

Well, I need to refresh my math from high school (centuries ago :-)) to remember what cosine and sine are. Many thanks for your explanation, Pablo -- http://www.ousia.tk