Changes between Version 5 and Version 7 of Ticket #13703


Ignore:
Timestamp:
03/15/13 13:37:24 (7 years ago)
Author:
jason
Comment:

Legend:

Unmodified
Added
Removed
Modified
  • Ticket #13703 – Description

    v5 v7  
    66def toeplitz(R,c,r): return matrix(R, len(c), len(r), lambda i,j: c[i-j] if i>=j else r[j-i])
    77def hankel(R,c,r): entries=c+r[1:]; return matrix(R, len(c), len(r), lambda i,j: entries[i+j])
    8 def circulant(R,E): return hankel(R, E, E[-1:]+E[:-1])
     8def circulant(R, E): return toeplitz(R, E[0:1]+E[-1:0:-1], E)
     9def skew_circulant(R,E): return hankel(R, E, E[-1:]+E[:-1])
    910
    1011#Hadamard matrices:
     
    5556
    5657Additionally, we could use scipy to create more matrices (or do it ourselves): http://docs.scipy.org/doc/scipy/reference/linalg.html#special-matrices
     58
     59(thanks to pascal on sage-support for correcting the circulant code above: https://groups.google.com/d/msg/sage-support/RnKjQ9n2YB0/vfCEvIV_HZUJ )