What is the graph or plot called which: - is an equilateral triangle - has three axes - each axes is perpendicular to a side of the triangle? [more inside]
posted by Peter Petridish on Oct 28, 2009 - 10 answers

Photoshop Question: is there a way to get a count of pixels contained within any (irregularly shaped) selection/layer? [more inside]
posted by unmake on Sep 10, 2009 - 2 answers

How can I estimate the time that a photo was taken? [more inside]
posted by zvs on Aug 5, 2009 - 11 answers

Is there an equation that defines the change in apparent size as a function of distance from the viewer? Basically, if I'm looking at a set of railroad tracks head on, if one plank is like 10 ft away, it appears to be one size. The same plank 20 ft away appears smaller. What is the relative size difference? Put another way, how big does a 1ft line appear to be at 10 ft, at 20 ft, etc.? [more inside]
posted by miasma on May 16, 2009 - 15 answers

I've got a polygon of n points. How can I simplify out noisy edges? [more inside]
posted by soma lkzx on Mar 31, 2009 - 12 answers

Hi I'm trying to find a piece of art - a series of lights attached to wooden arms whose tips trace some sort of toroidal geometry. At high speeds the armature disappears and the lights form volumes as luminous wireframes, like synchronised mechanical sparklers. [more inside]
posted by doobiedoo on Mar 5, 2009 - 5 answers

My daughter wants to decorate a sphere in a football pattern. How do we determine the correct side length for the pentagons and hexagons, given a sphere of diameter n?
posted by i_am_joe's_spleen on Jun 9, 2006 - 11 answers

Let's say I have an array of 100 adjoining hexagons, 10 hexagons per side. Let's also say I also have an array of 100 adjoining squares, 10 squares per side. Each single hexagon and each square encloses the same area. Is the perimeter of the array of 100 hexagons longer than the perimeter of the array of 100 squares? [more inside]
posted by Rumple on Apr 25, 2006 - 17 answers

I want a true vector-based (i.e., not merely a series of thousands of line segments) Postscript or Illustrator file of an epicycloid where a=5, b=2. [more inside]
posted by dmd on Feb 19, 2006 - 25 answers