Ideally, a code printer that printed a python function for this expression would automatically create the numpy code you show from the expression. But, I'm not sure any of the current printing facilities in sympy can do that. I tried lamdify, ccode, and codegen with no luck.
Jason moorepants.info +01 530-601-9791 On Fri, Jan 31, 2014 at 3:45 AM, Federico Vaggi <[email protected]>wrote: > Hi everyone, > > I was using SymPy to derive an analytic expression for a Jacobian matrix > in a least squares system. It worked very well, and I simplified the > system down to an equation which is very easy to evaluate, which however > involves a vector of residuals: > > The final SymPy expression is this: > > > Sum((-10.0*exp(-0.1*t) + 10.0)*d, (t, 1, 50)) > > > Where t is a variable, and d is an indexed base. How can I numerically > replace d with a vector containing 50 residuals, and actually compute the > sum? It would be trivial to code this up in numpy using a loop, but since I > was preparing an iPython notebook, I thought it would be nice to do as much > as possible within SymPy. > > > The equivalent numpy code would be this: > > > tot = 0.0 > > for t in range(50): > > tot += (-10*np.exp(-0.1*t) + 10)*d[t] > > > > -- > 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.
