Re: Additive inverses of lists?
- To: mathgroup at smc.vnet.net
- Subject: [mg95769] Re: Additive inverses of lists?
- From: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>
- Date: Mon, 26 Jan 2009 06:50:07 -0500 (EST)
- Organization: The Open University, Milton Keynes, UK
- References: <glk1l9$lmj$1@smc.vnet.net>
In article <glk1l9$lmj$1 at smc.vnet.net>,
Erik Max Francis <max at alcyone.com> wrote:
> Is this a known no-no, or did I find something new? (I obviously
> originally tried it in the graphical front end; I'm only doing it from
> the command line interface for demonstration.)
This seems to be new and this also works on Windows :-)
> max@boron:~% math
> Mathematica 7.0 for Linux x86 (32-bit)
> Copyright 1988-2008 Wolfram Research, Inc.
>
> In[1]:= StreamPlot[-{x, y}, {x, -3, 3}, {y, -3, 3}]
> zsh: segmentation fault math
Upon evaluation of the above line from within the front end, Visual
Studio Just-in-Time debugger traps the following error: "An unhandled
win32 exception occurred in MathKernel.exe [4060]"
Forcing the evaluation of the expression -{x, y} yields the expected
behavior and plot, though.
StreamPlot[Evaluate[-{x, y}], {x, -3, 3}, {y, -3, 3}]
In[5]:= {$Version, $ReleaseNumber}
Out[5]= {"7.0 for Microsoft Windows (32-bit) (November 10, 2008)", 0}
> Interestingly enough if the StreamPlot is not involved, nothing but happens:
>
> In[1]:= -{a, b}
>
> Out[1]= {-a, -b}
>
> And plotting {-x, -y} instead of -{x, y} works fine:
>
> In[1]:= StreamPlot[{-x, -y}, {x, -3, 3}, {y, -3, 3}]
>
> Out[1]= -Graphics-
Regards,
--Jean-Marc