MathGroup Archive 2005

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: problems plotting a derivative


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.

remove the dash if emailing




  • Prev by Date: Re: problems plotting a derivative
  • Next by Date: Re: Solutions of an equation under complex form
  • Previous by thread: Re: problems plotting a derivative
  • Next by thread: Re: problems plotting a derivative