Re: Plot problem
- To: mathgroup at smc.vnet.net
- Subject: [mg3612] Re: Plot problem
- From: ianc (Ian Collier)
- Date: Thu, 28 Mar 1996 00:10:35 -0500
- Organization: Wolfram Research, Inc.
- Sender: owner-wri-mathgroup at wolfram.com
In article <4j7hbd$af4 at dragonfly.wolfram.com>, Pierluigi Puccetti
<puccetti at sienanet.it> wrote:
> Chiara Mocenni Puccetti
> Universita' di Siena - ITALY
>
> f[t_]:=(22.39638707132903 - 38.3879329433359*I)*E^((-0.005 -
> 0.999987499921874*I)*t) +
>
> (7.912734995684308 - 0.5556111312856052*I)*Cos[1.1*t] +
>
> (-17.89146077765513 + 1.146859050666162*I)*Sin[1.1*t];
>
> This function is the solutin
> on (obtained with DSolve) of a system of two differential equations.
> There are complex numbers,
> and I am enable to plot this functions in the time variable.
> I am not yet really expert, there is someone that can help me ?
>
> Thanks you
>
> Chiara
Mathematica's plotting functions are only able to plot
quantities that evaluate to real numbers.
In this case you can plot either the real or imaginary
parts of the function - or you can plot one against the
other using ParametricPlot.
Here are some examples:
In[1]:=
f[t_]:=(22.39638707132903 - 38.3879329433359*I)*
E^((-0.005 - 0.999987499921874*I)*t) +
(7.912734995684308 - 0.5556111312856052*I)*Cos[1.1*t] +
(-17.89146077765513 + 1.146859050666162*I)*Sin[1.1*t];
In[2]:=
Plot[ Re[ f[t] ], {t,-10,10}]
Out[2]=
-Graphics-
In[3]:=
Plot[ Im[ f[t] ], {t,-10,10}]
Out[3]=
-Graphics-
In[4]:=
ParametricPlot[ {Re[ f[t] ], Im[ f[t] ]}, {t,-10,10}]
Out[4]=
-Graphics-
I hope this helps.
--Ian
-----------------------------------------------------------
Ian Collier
Wolfram Research, Inc.
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tel:(217) 398-0700 fax:(217) 398-0747 ianc at wolfram.com
Wolfram Research Home Page: http://www.wolfram.com/
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