Pb with ZeroTest
- To: mathgroup at smc.vnet.net
- Subject: [mg23608] Pb with ZeroTest
- From: Jack Michel CORNIL <jmcornil at club-internet.fr>
- Date: Wed, 24 May 2000 02:16:08 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Hello,
I am trying to use the option ZeroTest in the function Inverse
but I desperatly get a crash of the Kernel.
Can someone tell me what is wrong in the following lines ?
In[3]:=
m = Table[Sin[i + j - 1], {i, 3}, {j, 3}]
Simplify[Det[m]]
Out[3]=
{{Sin[1], Sin[2], Sin[3]}, {Sin[2], Sin[3], Sin[4]}, {Sin[3], Sin[4],
Sin[5]}}
Out[4]=
0
In[5]:=
mn = 0.001 Round[1000*(m // N)]
Inverse[mn]
Out[5]=
{{0.841, 0.909, 0.141}, {0.909, 0.141, -0.757},
{0.141, -0.757, -0.959}}
Out[6]=
{{7012.83, -7574.5, 7010.12}, {-7574.5, 8182.5, -7572.64},
{7010.12, -7572.64, 7007.21}}
so far so good since the initial matrix is singular !
But if I try to use the option ZeroTest, I crash the kernel :
In[7]:=
Inverse[mn, ZeroTest -> Function[x, Abs[x] <= 0.001]]
<<<<< C R A S H >>>>>>
What am I doing wrong ?
Thanks in advance
Jack-Michel CORNIL