MathAction #288 seriesSolve cannot find fixedPointExquo

Topics

FrontPage
- IssueTracker
  - #288 seriesSolve cannot find fixedPointExquo <-- You are here.

For some reason

fricas

(1) -> y:=operator 'y

$\label{eq1}y$

(1)

Type: BasicOperator?

fricas

seriesSolve(-1+(1-2*x)*y(x)-(1-4*x)*D(y(x),x)=0, y, x = 0, [1])

fricas

Compiling function %D with type List(UnivariateTaylorSeries(
      Expression(Integer),x,0)) -> UnivariateTaylorSeries(Expression(
      Integer),x,0)

$\label{eq2}\begin{array}{@{}l} \displaystyle 1 -{{x}^{2}}-{3 \ {{x}^{3}}}-{{\frac{37}{4}}\ {{x}^{4}}}-{{\frac{1 21}{4}}\ {{x}^{5}}}- \ \ \displaystyle {{\frac{2467}{24}}\ {{x}^{6}}}-{{\frac{60223}{168}}\ {{x}^{7}}}-{{\frac{570643}{448}}\ {{x}^{8}}}- \ \ \displaystyle {{\frac{55530089}{12096}}\ {{x}^{9}}}-{{\frac{2023798571}{120 960}}\ {{x}^{10}}}+ \ \ \displaystyle {O \left({{x}^{11}}\right)}$

(2)

Type: UnivariateTaylorSeries?(Expression(Integer),x,0)

fails. We need to expose UnivariateTaylorSeriesODESolver first:

fricas

)expose UnivariateTaylorSeriesODESolver

   UnivariateTaylorSeriesODESolver is now explicitly exposed in frame 
      initial 
seriesSolve(-1+(1-2*x)*y(x)-(1-4*x)*D(y(x),x)=0, y, x = 0, [1])

fricas

Compiling function %H with type List(UnivariateTaylorSeries(
      Expression(Integer),x,0)) -> UnivariateTaylorSeries(Expression(
      Integer),x,0)

$\label{eq3}\begin{array}{@{}l} \displaystyle 1 -{{x}^{2}}-{3 \ {{x}^{3}}}-{{\frac{37}{4}}\ {{x}^{4}}}-{{\frac{1 21}{4}}\ {{x}^{5}}}- \ \ \displaystyle {{\frac{2467}{24}}\ {{x}^{6}}}-{{\frac{60223}{168}}\ {{x}^{7}}}-{{\frac{570643}{448}}\ {{x}^{8}}}- \ \ \displaystyle {{\frac{55530089}{12096}}\ {{x}^{9}}}-{{\frac{2023798571}{120 960}}\ {{x}^{10}}}+ \ \ \displaystyle {O \left({{x}^{11}}\right)}$

(3)

Type: UnivariateTaylorSeries?(Expression(Integer),x,0)

Furthermore, the documentation of seriesSolve is not quite clear to me. Why does:

  seriesSolve(-1+(1-2*x)*y(x)+x*(1-4*x)*D(y(x),x)=0, y, x = 0, [1])

fail - it should give the Catalan numbers.

Martin

noticed possible duplicate --kratt6, Wed, 13 Dec 2006 06:41:06 -0600 reply

This one is at least related, if not identical? to #301

duplicate of #301, which was fixed in FriCAS --kratt6, Tue, 13 Jan 2009 04:08:03 -0800 reply

Status: open => duplicate

Subject: Be Bold !!

	( 15 subscribers )