Re: partial transpose
- To: mathgroup at smc.vnet.net
- Subject: [mg125506] Re: partial transpose
- From: Bill Rowe <readnews at sbcglobal.net>
- Date: Fri, 16 Mar 2012 06:31:56 -0500 (EST)
- Delivered-to: l-mathgroup@mail-archive0.wolfram.com
On 3/15/12 at 12:26 AM, kjsalini at gmail.com (jay) wrote:
>how to find partial transpose of a density matrix
How about defining what you mean by a partial transpose?
Perhaps something like:
In[5]:= a = RandomInteger[10, {5, 5}]
Out[5]= {{9, 2, 6, 5, 3}, {5, 2, 10, 6, 2}, {4, 7, 8, 6, 9}, {4, 10,
8, 3, 4}, {0, 0, 0, 9, 2}}
In[6]:= mask =
Unitize[1 - SparseArray[{Band[{3, 3}] -> Unitize[a[[;; 3, ;; 3]]]}]];
In[7]:= a mask +
SparseArray[{Band[{3, 3}] -> Transpose[a[[3 ;;, 3 ;;]]]}] // Normal
Out[7]= {{9, 2, 6, 5, 3}, {5, 2, 10, 6, 2}, {4, 7, 8, 8, 0}, {4, 10,
6, 3, 9}, {0, 0, 9, 4, 2}}