Prev: Integrate and GenerateConditions (bug?)
Next: Graphics questions
From: JustanotherDave on 29 May 2010 04:43
I'm having trouble getting Mathematica to plot what I would like from
a system of equations. I have the function

f[c_?NumericQ, m_?NumericQ, n_?NumericQ] :=
FindRoot[{a - b == 2*Pi*(m - n) + ArcTan[(a - b)/c],
a + b == 2*Pi*(m + n)}, {{a, 2 I + 1}, {b, -2 I + 1}}]

Which evaluates to something like {a -> 13.333 + 2.99972*10^-20 I, b -
> -13.333 - 2.99972*10^-20 I}
What I would like is to be able to plot the imaginary values of a and
b on the same graph (varying the parameter c, keeping m and n
constant) but I'm not sure how to convert the FindRoot output to
plotable values

From: David Park on 30 May 2010 06:46
Something like this?

f[c_?NumericQ, m_?NumericQ, n_?NumericQ] :=
FindRoot[{a - b == 2 \[Pi] (m - n) + ArcTan[(a - b)/c],
a + b == 2 \[Pi] (m + n)}, {{a, 2 I + 1}, {b, -2 I + 1}}]

fParametrization[c_] := Chop[{a, b} /. f[c, 2, 3]];
ParametricPlot[fParametrization[c], {c, 0, 5}]


David Park
djmpark(a)comcast.net
http://home.comcast.net/~djmpark/



From: JustanotherDave [mailto:david.holdaway(a)gmail.com]

I'm having trouble getting Mathematica to plot what I would like from
a system of equations. I have the function

f[c_?NumericQ, m_?NumericQ, n_?NumericQ] :=
FindRoot[{a - b == 2*Pi*(m - n) + ArcTan[(a - b)/c],
a + b == 2*Pi*(m + n)}, {{a, 2 I + 1}, {b, -2 I + 1}}]

Which evaluates to something like {a -> 13.333 + 2.99972*10^-20 I, b -
> -13.333 - 2.99972*10^-20 I}
What I would like is to be able to plot the imaginary values of a and
b on the same graph (varying the parameter c, keeping m and n
constant) but I'm not sure how to convert the FindRoot output to
plotable values



 | 
Pages: 1
Prev: Integrate and GenerateConditions (bug?)
Next: Graphics questions