InvP:

Path: Math/Linear

% The product form of the inverse

               [ 1     v1]-1
   inv(Bnew) = [    1  v2]  inv(Bold)
               [       v3] 

   v = inv(Bold)y where y is the new column k of B

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   Form:
   bInv = InvP( bInvOld, v, k )
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   ------
   Inputs
   ------
   bInvOld       (n,n)    Old inverse
   v             (n,1)    Vector = inv(Bold)*y where y is a new column of B
   k                      Column index of v

   -------
   Outputs
   -------
   bInv          (n,n)    New inverse

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