That's look great. Indeed, I'm looking for strategies to solve "simple" inequations of one variable.
Best regards. Christophe. smichr a écrit : > On Jul 16, 6:48 pm, Toon Verstraelen <toon.verstrae...@ugent.be> > wrote: > >> Christophe wrote: >> >>> Hello, >>> suppose that we have the following expression : >>> (x**2+1)*(log(x+4)-7) >>> >>> I would like to know that is a product and to have : >>> (x**2+1) and (log(x+4)-7). >>> > > In terms of equations, there are 4 main types that I tend to think > about: those involving addition, multiplication or division, > functions, and powers. You have to ask sympy what you have, so if you > have something named eq and you don't know what it is (but in this > example you will see that it is your function) you use the is_* > methods. > > ### > >>>> eq.is_Add >>>> > False > >>>> eq.is_Mul >>>> > True > ### > > > Now that you know it involves terms multiplied together, you can ask > for the terms with 'args': > > ### > >>>> eq.args >>>> > (-1, 1 + x**2, 7 - log(4 + x)) > ### > > So sympy sees eq as being a product of 3 terms. If you want, you could > look at the individual terms, looking for the function, but it is > easier to just ask for the Function-type atoms of the equation; the > atoms(Function) method will only scan at what you call "the first > level" (but atoms() with no argument will scan deeper for all numbers > and symbols that appear): > > ### > >>>> eq.atoms(Function) >>>> > set([log(4 + x)]) > >>>> (log(sin(x)+2)).atoms() >>>> > set([2, x]) > >>>> (log(sin(x)+2)).atoms(Function) >>>> > set([log(2 + sin(x))]) #there is only 1 element in the set, a log > (with its arguments) > > > Hope that helps, > /chris > > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to sympy@googlegroups.com To unsubscribe from this group, send email to sympy+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sympy?hl=en -~----------~----~----~----~------~----~------~--~---
