It can generally be used to express it in some limited cases yes, but I don't think it goes very far down the direction that I suspect fedeperazzi wants to pursue. In general Matrix expressions weren't designed for much beyond linear algebra operations. Extending them to array indexing operations will likely lead to disappointment. This is more in line with the design intent of Indexed. It could also be done with just straight functions. This application may also be a good candidate for Theano.
On Tue, Sep 24, 2013 at 8:49 PM, Aaron Meurer <[email protected]> wrote: > Is the MatrixElement class not suited for this? > > Aaron Meurer > > On Tue, Sep 24, 2013 at 8:26 PM, Matthew Rocklin <[email protected]> > wrote: > > Matrix expressions isn't designed for this. The long neglected Indexed > is > > probably the closest match. I don't know if it covers this application. > > > > This is an important application though (and could be generalized > nicely). > > > > > > On Tue, Sep 24, 2013 at 6:29 PM, Aaron Meurer <[email protected]> > wrote: > >> > >> I'm not entirely clear what you are trying to do, but some of the > >> stuff in the matrix expressions module may be of use to you. > >> > >> Aaron Meurer > >> > >> On Tue, Sep 10, 2013 at 5:15 AM, <[email protected]> wrote: > >> > Hi, I am trying to achieve the following: > >> > > >> >>>> f = Function('f')(M,x) > >> >>>> f = M[x+1] - M[x] > >> >>>> F = lambdify(f) > >> >>>> print F(np.array([5,2,1]),1) > >> >>>> 3 > >> > > >> > What would be the best way to do it? > >> > > >> > > >> > By the way this is part of a bigger goal i.e. discretize derivatives > of > >> > arbitrary order, but I am totally a newbie and I have to go step by > >> > step... > >> > (See my post here: > >> > > >> > > http://stackoverflow.com/questions/18701290/derivatives-discretization-with-sympy > ) > >> > > >> > -- > >> > You received this message because you are subscribed to the Google > >> > Groups > >> > "sympy" group. > >> > To unsubscribe from this group and stop receiving emails from it, send > >> > an > >> > email to [email protected]. > >> > To post to this group, send email to [email protected]. > >> > Visit this group at http://groups.google.com/group/sympy. > >> > For more options, visit https://groups.google.com/groups/opt_out. > >> > >> -- > >> You received this message because you are subscribed to the Google > Groups > >> "sympy" group. > >> To unsubscribe from this group and stop receiving emails from it, send > an > >> email to [email protected]. > >> To post to this group, send email to [email protected]. > >> Visit this group at http://groups.google.com/group/sympy. > >> For more options, visit https://groups.google.com/groups/opt_out. > > > > > > -- > > You received this message because you are subscribed to the Google Groups > > "sympy" group. > > To unsubscribe from this group and stop receiving emails from it, send an > > email to [email protected]. > > To post to this group, send email to [email protected]. > > Visit this group at http://groups.google.com/group/sympy. > > For more options, visit https://groups.google.com/groups/opt_out. > > -- > You received this message because you are subscribed to the Google Groups > "sympy" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/sympy. > For more options, visit https://groups.google.com/groups/opt_out. > -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sympy. For more options, visit https://groups.google.com/groups/opt_out.
