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Re: Problem: Approximate complex values in Mathematica 8.0.1

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Your example works on my Mac's version 8.0.1

{$Version, $ReleaseNumber}

{"8.0 for Mac OS X x86 (64-bit) (February 23, 2011)", 1}

fnc = Interpolation[{{0, 0}, {2, 2}}, InterpolationOrder -> 1];

fnc[1. I/I]

1.


Bob Hanlon

---- dr DanW <dmaxwarren@gmail.com> wrote: 

=============
As noted in this discussion:
https://groups.google.com/d/topic/comp.soft-sys.math.mathematica/K06SxXE72gM/discussion

The way Mathematica 8.0.1 handles approximate complex values has changed.  In the related discussion, the change only seemed to effect the way approximate complex values were displayed

In[28]:=N[8*I]

Out[28]= 0. + 8. I

This is different from prior behavior, where the answer was 8. I

Now I have found a situation where it causes a package I wrote to fail.  The simplest embodiment of the problem I can find is:

In[29]:= fnc = Interpolation[{{0, 0}, {2, 2}}, InterpolationOrder -> 1];

In[30]:= fnc[1. I/I]

Out[30]= InterpolatingFunction[][1. + 0. I]

The function does not evaluate because it is expecting a real input.  I can't confirm that this is new to 8.0.1 (no old installations of Mathematica around), but I have never encountered this problem with my package before.  

Remember, I have reduced the problem to triviality for this posting.  In the actual application, the situation is much more complex and deeply buried, so even the obvious simple workarounds are not available to me without lots of work.

Daniel

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Re: Problem: Approximate complex values in Mathematica 8.0.1 Bob Hanlon <hanlonr@cox.net> - 2011-04-02 22:04 +0000

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