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There are several "versions" of ovals. Descartes' ovals take the form f*d1+g*d2=s d1, d2 are the distances of a point on the curve to the two foci (as with an ellipse) f, g are rational numbers. I've taken f<1 and g=1. s is a number fixed for a given curve. The equation 2*d1+d2=s can be drawn as follows. As for an ellipse, put 2 tacks into a sheet of paper. Take a piece of string length, s. Tie one end to one tack. Insead of tying the other end to the other tack as for the ellipse tie it to a pencil and then loop the string round the remaining tack. The pencil is tensioned against the string (as for an ellipse). The string length is thus made up of 2 lengths of d1 and one of d2. Mike  Original Message  From: "Russell, Ken" <krussell@xxxxxxxxxxxxxxx> To: <mwforum@xxxxxxxxxxxxxxxxxxxxxxxxxxxx> Sent: Thursday, March 08, 2007 6:29 PM Subject: oval question How would one write a procedure to create an oval in logo? I think it will use a little trig in there (sin?), but I'm (really) unclear on the concept. Attachment:
oval_forum.mw2 To save an attachment to your computer, PC users should rightclick (Mac users, click and hold the mouse button) on the link and then choose 'save target as' from the popup menu. A window will then pop up in which you can choose a location for the file. 