Re: problems plotting a derivative
- To: mathgroup at smc.vnet.net
- Subject: [mg54520] Re: [mg54479] problems plotting a derivative
- From: "David Park" <djmp at earthlink.net>
- Date: Tue, 22 Feb 2005 04:23:38 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
You have to Evaluate the entire parametrization.
ParametricPlot[{D[f[x], x], x^2} // Evaluate, {x, 0, 1}]
Or you could use...
ParametricPlot[{f'[x], x^2}, {x, 0, 1}]
David Park
djmp at earthlink.net
http://home.earthlink.net/~djmp/
From: J. K. Smith [mailto:rob at pi-overe.com]
To: mathgroup at smc.vnet.net
I've tried a lot of ways but nothing has worked so far.
The following statements are my problem simplified:
f[x_] := 2x^3;
ParametricPlot[{D[f[x], x], x^2}, {x, 0, 1}]
When I run this I get error messages griping about numbers not being
valid variables but it doesn't end up plotting anything. In this example
I should see a straight line.
I've tried using Evaluate[ D[f[x],x] ] and lots of other schemes which
seemed to work in the past but I can't get ParametricPlot to digest any
of them. Something about the result of that derivative doesn't yield
something that can be plotted. But I don't know what property it is.
Would you kind Mathematica gurus please get me thru this one (too)?
Thanks.
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