matrices.py

   1 from cvxopt import matrix, spmatrix
   2 from math import sqrt
   3
   4 def append_col(A,b):
   5     """
   6     Append the column ``b`` to the right side of the matrix ``A``.
   7     """
   8     return matrix([A.trans(),b.trans()]).trans()
   9
  10 def append_row(A,b):
  11     """
  12     Append the row ``b`` to the bottom of the matrix ``A``.
  13     """
  14     return matrix([A,b])
  15
  16 def identity(n):
  17     """
  18     Return the ``n``-by-``n`` identity matrix.
  19     """
  20     return spmatrix(1,range(n),range(n))
  21
  22 def norm(x):
  23     """
  24     Return the Euclidean norm of the given vector.
  25     """
  26     return sqrt(sum([z**2 for z in x]))