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Submitted by : (unknown) at: 2007-11-17T22:21:41-08:00 (9 years ago)
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Category : Severity : Status :
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For some reason

axiom
y:=operator 'y

\label{eq1}y(1)
Type: BasicOperator
axiom
seriesSolve(-1+(1-2*x)*y(x)-(1-4*x)*D(y(x),x)=0, y, x = 0, [1])
axiom
Compiling function %B 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}}-{{{37}\over 4}\ {x^4}}-{{{121}\over 4}\ {x^5}}-{{{2467}\over{24}}\ {x^6}}-{{{60223}\over{168}}\ {x^7}}- \
\
\displaystyle
{{{570643}\over{448}}\ {x^8}}-{{{55530089}\over{12096}}\ {x^9}}-{{{2023798571}\over{120960}}\ {x^{10}}}+{O \left({x^{11}}\right)}
(2)
Type: UnivariateTaylorSeries(Expression(Integer),x,0)

fails. We need to expose UnivariateTaylorSeriesODESolver first:

axiom
)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])
axiom
Compiling function %D 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}}-{{{37}\over 4}\ {x^4}}-{{{121}\over 4}\ {x^5}}-{{{2467}\over{24}}\ {x^6}}-{{{60223}\over{168}}\ {x^7}}- \
\
\displaystyle
{{{570643}\over{448}}\ {x^8}}-{{{55530089}\over{12096}}\ {x^9}}-{{{2023798571}\over{120960}}\ {x^{10}}}+{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




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