Procedure: minvar.pro This program computes the principal variance directions and variances of a vector quantity (can be 2D or 3D) as well as the associated eigenvalues. This routine is a simple version designed to be used by a tplot wrapper with the contrans_var library Works with trired and triql (IDL's version of Num. Recipies w/ permission) Input: Vxyz, an (ndim,npoints) array of data(ie 3xN) Output: eigenVijk, an (ndim,ndim) array containing the principal axes vectors Maximum variance direction eigenvector, Vi=eigenVijk(*,0) Intermediate variance direction, Vj=eigenVijk(*,1) (descending order) Vrot: if set to a name, that name becomes an array of (ndim,npoints) containing the rotated data in the new coordinate system, ijk. Vi(maximum direction)=Vrot(0,*) Vj(intermediate direction)=Vrot(1,*) Vk(minimum variance direction)=Vrot(2,*) lambdas2=if set to a name returns the eigenvalues of the computation Written by: Vassilis Angelopoulos $LastChangedBy: jimm $ $LastChangedDate: 2010-04-13 11:49:40 -0700 (Tue, 13 Apr 2010) $ $LastChangedRevision: 7502 $ $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/trunk/general/cotrans/special/minvar/minvar.pro $