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Topic: Labelling each curve and changing grid in ParametricPlot
Replies: 3   Last Post: Feb 3, 2013 2:51 AM

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 David Park Posts: 1,560 Registered: 5/19/07
Re: Labelling each curve and changing grid in ParametricPlot
Posted: Feb 3, 2013 2:51 AM

Ed,

This is a little difficult because the curves are so closely spaced. One has
to make the plot rather large to identify the labels with the curves. In the
following example I put the labels all at the end of the curves and labeled
only every other one. I also put Tooltips on the curves in case it is being
viewed in a notebook.

I don't understand what you mean by having the Grid based on Omega. I just
drew a grid but make it very light and avoided the Dashed style (a al
Tufte).

<< Presentations`

plot[\[Tau]_, \[CapitalOmega]_] :=
Module[{arg, abs}, {arg, abs} =
Factor[Together[
ComplexExpand[
Through[{Arg,
Abs}[(1 + I*2*\[CapitalOmega])/(1 +
I*2*\[Tau]*\[CapitalOmega])]]]]];
{arg/Degree, 20*Log10[abs]}]

Draw2D[
{ParametricDraw[
Tooltip[plot[#, \[CapitalOmega]], #], {\[CapitalOmega], -0.5,
0.01}] & /@ {7, 8, 9, 10, 11, 12, 13, 14, 15},
Text[Framed[Style[phrase["\[Tau] = ", #], 12], FrameMargins -> 0],
plot[#, -0.5], {1, 0}, Background -> White] & /@ {8, 10, 12, 14}},
AspectRatio -> 1,
Frame -> True, FrameLabel -> {"phase/\[Degree]", "db"},
RotateLabel -> False,
GridLines -> {CustomGridLines[# &, {-10, 60, 10}, {LightGray}],
CustomGridLines[# &, {-20, 0, 5}, {LightGray}]},
BaseStyle -> {FontSize -> 12},
ImageSize -> 600]

David Park
djmpark@comcast.net
http://home.comcast.net/~djmpark/index.html

From: Eduardo M. A. M. Mendes [mailto:emammendes@gmail.com]

Hello

I wonder whether someone out there could help me with the following problem.

plot[\[Tau]_, \[CapitalOmega]_] := Module[{arg, abs},
{arg, abs} = Factor[Together[ComplexExpand[
Through[{Arg, Abs}[(1 + I*2*\[CapitalOmega])/(1 +
I*2*\[Tau]*\[CapitalOmega])]]]]];
{arg/Degree, 20*Log10[abs]}]

ParametricPlot[Table[plot[\[Tau], \[CapitalOmega]], {\[Tau], {7, 8, 9, 10,
11, 12, 13, 14, 15}}],
{\[CapitalOmega], -0.5, -0.01}, AspectRatio -> 1, GridLines -> Automatic,
GridLinesStyle -> Dashed, ImageSize -> Large]

I need to label each curve with the value of tau and, instead of the normal
grid, a grid based on the values of Omega.

I saw something related to the label problem on the net but could not figure
out how to change it to my case. Something with Epilog.

Many thanks

Ed

Date Subject Author
2/3/13 emammendes@gmail.com
2/3/13 David Park