Re: Plotting complex functions
- To: mathgroup at smc.vnet.net
- Subject: [mg24163] Re: Plotting complex functions
- From: piovere at pdq.net (rob)
- Date: Wed, 28 Jun 2000 22:50:45 -0400 (EDT)
- References: <8ihvf8$lgj@smc.vnet.net> <8ikbp4$qaa@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Say, I tried you example but for some reason I get the err msg that
ParametricPlot does not evaluate to a pair of real numbers.
Should this work on my version 4.0?
Thanks, Rob
On 19 Jun 2000 01:40:52 -0400, "Kevin J. McCann"
<kevinmccann at Home.com> wrote:
>Matthijs ,
>
>In order to plot, the function has to produce numbers. Your example below
>has two undetermined integration constants; so, the result will not produce
>a number. Try the example below. I picked the IC's so that the result would
>be complex.
>
>Paste these into a NB
>
>f=y/.DSolve[{y''[t] + y'[t] + y[t] == 0,y[0]==I,y'[0]==1}, y, t]
>
>ParametricPlot[{Re[f[x]], Im[f[x]]}, {x, 0, 10},
> Epilog -> {RGBColor[1, 0, 0], AbsolutePointSize[5],
>Point[{Re[f[0.]], Im[f[0.]]}]}];
>
>Cheers,
>
>Kevin
>
>"Matthijs Sypkens Smit" <matthijs at helena.tux.nu> wrote in message
>news:8ihvf8$lgj at smc.vnet.net...
>> Hi,
>>
>> How do I make a plot of a complex-valued function, such as y after
>> DSolve[y''[t] + y'[t] + y[t] == 0, y, t]
>>
>> I've tried a ParametricPlot with Re[y[t] and Im[y[t], but either that
>> doesn't work or I'm doing it wrong. Any pointers or an example?
>>
>> --
>> Matthijs
>>
>
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