#6229: efficiency in Lagrange polynomial interpolation (easy fix...)
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Reporter: ylchapuy | Owner: tbd
Type: defect | Status: new
Priority: minor | Milestone: sage-4.0.1
Component: algebra | Keywords:
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Description changed by ylchapuy:
Old description:
> This is a follow-up to #6043.
>
> This nested loop is useless:
> {{
> P = 0
> for i in xrange(n):
> prod = 1
> for j in xrange(i):
> prod *= (x - points[j][0])
> P += (F[i] * prod)
> return P
>
> }}
>
> and should be replaced with (something like)
>
> {{
> P = F[n-1]
> for i in xrange(n-2,-1,-1):
> P *= (x - points[i][0])
> P += F[i]
> return P
> }}
New description:
This is a follow-up to #6043.
This nested loop is useless:
{{{
P = 0
for i in xrange(n):
prod = 1
for j in xrange(i):
prod *= (x - points[j][0])
P += (F[i] * prod)
return P
}}}
and should be replaced with (something like)
{{{
P = F[n-1]
for i in xrange(n-2,-1,-1):
P *= (x - points[i][0])
P += F[i]
return P
}}}
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Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/6229#comment:1>
Sage <http://sagemath.org/>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
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