On Sun, Mar 6, 2016 at 12:42 AM, shubham tibra <[email protected]> wrote: > Regarding the initial conditions in multiplication and addition when they > are not at the same point: > > I think the best is(already discussed at ideas page) first to check if both > the given holonomic functions are elementary function and calculate the > initial conditions at a same point symbolically, where both the functions > doesn't have a pole. So for the resulting function the initial condition > would be addition/multiplication of calculated conditions at that point. > > In case when one or both can't be converted to elementary we will calculate > numerical value at a point and add/multiply them.
Right. The numerical initial condition is the last resort, as at that point, we can't really convert it back to a symbolic form. But I think it's still useful, since if you know the holonomic function, but not the initial condition (or only numerically), this still restricts what the function looks like. For example the differential equation f''(x) + f(x) = 0 always has a solution of the form sin(a*x+b), so you know that the function is a sinusoid, you just don't know the exact parameters "a" and "b" without the initial condition, or only know them numerically, so you can't convert it to, say, sin(x), but the result is still useful. > > How are we gonna do this in INTEGRATION and DIFFERENTIATION? > > In application with a algebraic function, let's say we have initial > condition at x0, then if it's possible we can get the point where the > algebraic function is equals to x0, let it be x1 ,and now we have the > initial condition of resulting function at the point x1. For derivatives we > will multiply the given initial condition with the corresponding derivative > of algebraic function at x1. Is this method suitable enough? I don't understand your question. Can you formulate it on a particular example? Ondrej > > I'd appreciate to know your views on it. > > Thanks > > -- > 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 https://groups.google.com/group/sympy. > To view this discussion on the web visit > https://groups.google.com/d/msgid/sympy/21859ab1-f780-4d91-9e22-7f7303a47ad4%40googlegroups.com. > > For more options, visit https://groups.google.com/d/optout. -- 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 https://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/CADDwiVDv1%2B04OwaSGH73s-s3hJS8xLu1XwegvZ1W28ZBSHqC6Q%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
