#16203: conversion from SR.series() to PowerSeries(SR) gives unexpected result
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Reporter: rws | Owner:
Type: defect | Status: new
Priority: major | Milestone: sage-6.2
Component: algebra | Keywords: series conversion
Merged in: | Authors:
Reviewers: | Report Upstream: N/A
Work issues: | Branch:
Commit: | Dependencies:
Stopgaps: |
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{{{
sage: R.<x> = PowerSeriesRing(SR)
sage: var('y')
y
sage: ex=1/(1-y)
sage: ex.series(y,20)
1 + 1*y + 1*y^2 + 1*y^3 + 1*y^4 + 1*y^5 + 1*y^6 + 1*y^7 + 1*y^8 + 1*y^9 +
1*y^10 + 1*y^11 + 1*y^12 + 1*y^13 + 1*y^14 + 1*y^15 + 1*y^16 + 1*y^17 +
1*y^18 + 1*y^19 + Order(y^20)
sage: s=R(_); s
1 + y + y^2 + y^3 + y^4 + y^5 + y^6 + y^7 + y^8 + y^9 + y^10 + y^11 + y^12
+ y^13 + y^14 + y^15 + y^16 + y^17 + y^18 + y^19 + Order(y^20)
sage: type(s)
<type 'sage.rings.power_series_poly.PowerSeries_poly'>
sage: s.list()
[1 + 1*y + 1*y^2 + 1*y^3 + 1*y^4 + 1*y^5 + 1*y^6 + 1*y^7 + 1*y^8 + 1*y^9 +
1*y^10 + 1*y^11 + 1*y^12 + 1*y^13 + 1*y^14 + 1*y^15 + 1*y^16 + 1*y^17 +
1*y^18 + 1*y^19 + Order(y^20)]
}}}
The correct result would be `1 + x + x^2...`. Obviously `Order(20)` is not
recognized as a marker for the existence of a power series. The whole
symbolic expression is taken as a constant.
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Ticket URL: <http://trac.sagemath.org/ticket/16203>
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