Unimodular transformation matrix of LLL algorithm

[Santanu Sarkar]

Dear all,

   I have a matrix M1 with integer entries with 90 rows and 6 columns.

After applying LLL algorithm of M1, I get M2=M1.LLL(). I want to get

corresponding unimodular transformation matrix T such that

T*M1=M2. We can find T by

T=M2*M1.pseudoinverse() or T== M1.solve_left(M2), but determinant of T becomes 0 i.e.,  T.det()=0.

I want T.det()=1.

Best regards,

Santanu

[slelievre]

Note: also asked on Ask Sage:

- Unimodular transformation matrix of LLL algorithm
  https://ask.sagemath.org/question/53618