[SciPy-user] numpy 1.0b1: arccosh(0.0)

Pierre SCHNIZER p.schnizer at gsi.de
Fri Aug 4 06:05:59 CDT 2006


Hello,

	I don't know if that only happens on my machine....
For numpy 1.0 b1 I get

<snip>
In [241]:numpy.arccosh(0)
Out[241]:nan

In [242]:numpy.arccosh(0+0j)
Out[242]:(-inf+0j)

In [243]:numpy.__version__
Out[243]:'1.0b1'
</snip>

I think the real part should be 0. and the complex part pi/2
I get these results for

<snip>
In [244]:numarray.arccosh(0+0j)
Out[244]:1.5707963267948966j
In [245]:numarray.__version__
Out[245]:'1.5.1'

In [247]:Numeric.arccosh(0+0j)
Out[247]:1.5707963267948966j

In [248]:Numeric.__version__
Out[248]:'24.2'

</snip>
I am running on
Linux mtpc18 2.6.17.7 #13 SMP PREEMPT Thu Jul 27 16:18:46 CEST 2006 i686 
GNU/Linux
Debian stable
I used the compiler
gcc (GCC) 3.3.5 (Debian 1:3.3.5-13)
Copyright (C) 2003 Free Software Foundation, Inc.
to compile the package.


I had the same problem with numpy 0.9.8. (Just discovered now)
Is that a problem only occuring on my installation?

Thanks for your help!

	Pierre



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