ASKSAGE: Sage Q&A Forum - RSS feedhttps://ask.sagemath.org/questions/Q&A Forum for SageenCopyright Sage, 2010. Some rights reserved under creative commons license.Wed, 15 Jan 2020 10:59:29 +0100matrix base ring changes by a complex multiplicationhttps://ask.sagemath.org/question/49557/matrix-base-ring-changes-by-a-complex-multiplication/The complex multiplication of matrix changes the base ring.
A = matrix(CDF,[[1,2],[3,4]]); print(A)
B = 2*A
C = I*A
print(type(A))
print(type(B))
print(type(C))
The result is
[1.0 2.0]
[3.0 4.0]
<class 'sage.matrix.matrix_complex_double_dense.Matrix_complex_double_dense'>
<class 'sage.matrix.matrix_complex_double_dense.Matrix_complex_double_dense'>
<class 'sage.matrix.matrix_symbolic_dense.Matrix_symbolic_dense'>
So the multiplication by an imaginary number breaks the CDF property.
This is very inconvenient for numerical calculations, because the symbolic computation is very slow.cxrjddWed, 15 Jan 2020 10:59:29 +0100https://ask.sagemath.org/question/49557/Elliptic curve scalar multiplication algorithmhttps://ask.sagemath.org/question/32886/elliptic-curve-scalar-multiplication-algorithm/ I'm doing a prespective on supersinguar elliptic curves. I was wondering how saga calculates scalar multiplications? Does it just calculate it naively or does it use succesive doubling as default? Til is most interesting since there are well known ways of making "shortcuts" when oberating with supersingular curves, but does sage use these?BelphegorFri, 25 Mar 2016 14:41:10 +0100https://ask.sagemath.org/question/32886/