Revision history [back]

Hi,

I'm beginning with Sage. I've got two matrix Qf and Xf defined by :

Qf = 1000000*matrix([[0,0],[0,1]]);
Xf = matrix([1],[1675]);

I would like to write a symbolic function "f" which would take a matrix X with 2 rows & 1 column.

X = var('X');
f(X) = ((X-Xf).transpose()*Qf*(X-Xf));

I easily wrote it with python non-symbolic function syntax, but i didn't find a way to make it symbolic. Because I'll need his gradient later (which is easy to calculate by hand, that I conceed ^^).

Maybe, it's related with SR matrix, no idea, i'm beginning with Sage and that's why I'm asking for help x)

Thank you in advance.

Hi,

I'm beginning with Sage. I've got two matrix Qf and Xf defined by :

Qf = 1000000*matrix([[0,0],[0,1]]);
Xf = matrix([1],[1675]);

I would like to write a symbolic function "f" which would take a matrix X with 2 rows & 1 column.

X = var('X');
f(X) = ((X-Xf).transpose()*Qf*(X-Xf));

I easily wrote it with python non-symbolic function syntax, but i didn't find a way to make it symbolic. Because I'll need his gradient later (which is easy to calculate by hand, that I conceed ^^).

Maybe, it's related with SR matrix, no idea, i'm beginning with Sage and that's why I'm asking for help x)

Thank you in advance.