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RowReduce::luc when using NSolve

• To: mathgroup at smc.vnet.net
• Subject: [mg99135] RowReduce::luc when using NSolve
• From: mereandor <mereandor at gmail.com>
• Date: Tue, 28 Apr 2009 04:44:38 -0400 (EDT)

I try to solve a linear equation with the following input to mathematica:

NSolve[{BesselJ[0, 20] - BesselJ[0, 20] r[0] == 3 I BesselJ[0, 60 I] t[0], BesselJ[0, 20] + BesselJ[0, 20] r[0] == BesselJ[0, 60 I] t[0]}, {r[0], t[0]}]

but I get

RowReduce::luc: Result for RowReduce of badly conditioned matrix \
{{-0.167025+0. I,-1.61061*10^9-<<21>> I,0.167025+0. I},{<<1>>}} may \
contain significant numerical errors. >>

This is only the simplest instance of my problem (2(n+1) equations in equally numbered variables). If I don't write the equations down literally but insert them into NSolve as a Table[] statement I don't even get the warning. Then the equations are solved only partially expressing t[n] as linear combination of r[n].

I use Mathematica 6.0

How can I resolve this?

Thanks in advance for any help!

• Follow-Ups:
  • Re: RowReduce::luc when using NSolve
    • From: Daniel Lichtblau <danl@wolfram.com>