Services & Resources / Wolfram Forums / MathGroup Archive
-----

MathGroup Archive 2009

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: Counting Categories

  • To: mathgroup at smc.vnet.net
  • Subject: [mg96833] Re: [mg96798] Counting Categories
  • From: DrMajorBob <btreat1 at austin.rr.com>
  • Date: Thu, 26 Feb 2009 07:51:33 -0500 (EST)
  • References: <200902250903.EAA15666@smc.vnet.net>
  • Reply-to: drmajorbob at bigfoot.com

Something like:

colors = {red, yellow, green, blue};
sizes = {small, medium, large};
randomColor := RandomChoice@colors
randomSize := RandomChoice@sizes
pairs = Table[{randomColor, randomSize}, {50}];

Partition[Count[pairs, #] & /@ Tuples[{colors, sizes}], Length@sizes]

{{5, 3, 3}, {3, 6, 3}, {8, 1, 2}, {5, 4, 7}}

or

Apply[Count[pairs, {##}, 1] &, Outer[List, colors, sizes], {2}]

{{5, 3, 3}, {3, 6, 3}, {8, 1, 2}, {5, 4, 7}}

Bobby

On Wed, 25 Feb 2009 03:03:33 -0600, Gregory Lypny  
<gregory.lypny at videotron.ca> wrote:

> Hello Everyone,
>
> I'm trying to do multivariate category counts in the way that used to
> be handled by CategoryCounts but is now replaced by Cases.  The
> example in Help simply applies Cases twice to find the count of
> elements in a list that are numbers and the count that is even.
>
> Map[Cases[{a, b, c, 1, 2, d, 3}, #] &, {_?NumberQ, _?EvenQ}]
>
> {{1, 2, 3}, {2}}
>
> But what if I have many rows of observations on two dimensions
> (columns) such as red, blue, green, and small, medium, big?  I'd like
> to be able categorize them accordingly as the count of small and red,
> medium and red, big and red, and so on.  Any way to do that?
>
> 	Regards,
>
> 		Gregory
>
>
>
>



-- 
DrMajorBob at longhorns.com


  • Prev by Date: Re: Inverse of a Big Matrix
  • Next by Date: Re: Map and functional constructs to replace iterative statements
  • Previous by thread: Re: Counting Categories
  • Next by thread: Re: Counting Categories