# Plot curves like equation problems

I'm proving to plot and edit some wolfram alpha laminae, but when I try it, I don't have any result, for example:

yamahaEquation =
WolframAlpha[
"Yamaha symbol\[Hyphen]like equation", \
{{"DefiningInequalitiesPod:Lamina", 1}, "ComputableData"}];

GraphicsRow[{
yamahaRegionPlot =
RegionPlot[
Evaluate[yamahaEquation[]],  {x, -0.5, 0.6}, {y, -0.6, 0.6},
PlotPoints -> 50, MaxRecursion -> 1, Frame -> False],
Plot3D[Evaluate[ yamahaEquation[[1, 1]] ],  {x, -0.5,
0.6}, {y, -0.6, 0.6}, Mesh -> False, MaxRecursion -> 6,
RegionFunction -> (Norm[{#1, #2}] <= 1/2 &),
ViewPoint -> {0, 0, 4}, Boxed -> False, Axes -> False]}] => (Blank image)


or

WolframAlpha["ferrari symbol like equation"] => WolframAlpha["ferrari symbol like equation", {{"Result", 1},
"ComputableData"}] => Missing["NotAvailable"]


Somebody knows how to resolve it?

Thanks

• Welcome to Mathematica.SE! I suggest the following: 1) As you receive help, try to give it too, by answering questions in your area of expertise. 2) Read the faq! 3) When you see good questions and answers, vote them up by clicking the gray triangles, because the credibility of the system is based on the reputation gained by users sharing their knowledge. Also, please remember to accept the answer, if any, that solves your problem, by clicking the checkmark sign! – Mahdi Apr 29 '15 at 8:10

The "Yamaha Equation" lamina is a function of two variables {x, y} and a parameter a. So, you need to supply something numeric for the a before you can plot.

yamahaRegionPlot = RegionPlot[
Evaluate[yamahaEquation[]] /. {a -> 1},  {x, -0.5, 0.6}, {y, -0.6, 0.6},
PlotPoints -> 50,
Frame -> False];

yamaha3D = Plot3D[
Evaluate[yamahaEquation[[1, 1]]] /. {a -> 1}, {x, -0.5, 0.6}, {y, -0.6, 0.6},
Mesh -> False,
MaxRecursion -> 6,
RegionFunction -> (Norm[{#1, #2}] <= 1/2 &),
ViewPoint -> {0, 0, 4},
Boxed -> False,
Axes -> False]


Although it would be a pain to check every lamina to see if there is an extra parameter like this, there is actually a fairly easy way out, because Mathematic already incorporates a lot of Wolfram|Alpha functionality (since v10). In this case there is function LaminaData that you can use:

yamahaEquation = LaminaData["YamahaEquation", "Inequalities"]

(* -> Function[a, Function[{x, y}, inequalities... ]] *)


This gives you the inequalities as a function of {x, y} nested inside a function of the parameter a. You can see that there is a parameter, by running

parameter = LaminaData["YamahaEquation", "Variables"]

(* -> {a} *)


The LaminaData function gives you easy access to a lot of other nice data about the laminae, so check out the documentation.