Issue 230 in mpmath: Laguerre problem

[mpm...@googlecode.com]

Status: New
Owner: ----

New issue 230 by D.Vutshi: Laguerre problem
http://code.google.com/p/mpmath/issues/detail?id=230

What steps will reproduce the problem?
1. run
import mpmath as mp
mp.laguerre(1,99,100.0)


What is the expected output? What do you see instead?
It should give zero. It produces error.

What version of the product are you using? On what operating system?
Mac OS 10.8, Linux Mint, mpmath 0.17 with gmpy

Please provide any additional information below.

[mpm...@googlecode.com]

Comment #1 on issue 230 by fredrik....@gmail.com: Laguerre problem
http://code.google.com/p/mpmath/issues/detail?id=230

I get:

ValueError: hypsum() failed to converge to the requested 73 bits of
accuracy
using a working precision of 3588 bits. Try with a higher maxprec,
maxterms, or set zeroprec.

This is expected, because the zero is nontrivial and cannot be detected by
the numerical algorithm. As the output suggests, you can force it to return
0 by passing zeroprec:

>>> mp.laguerre(1, 99, 100, zeroprec=1000)
mpf('0.0')

[mpm...@googlecode.com]

Comment #2 on issue 230 by D.Vutshi: Laguerre problem
http://code.google.com/p/mpmath/issues/detail?id=230

I see, sorry for false alarm :)