Skip to main content
P
ptc-50975041-Visitor
1-Visitor
September 17, 2013
Question

3D plot problems

  • September 17, 2013
  • 2 replies
  • 2903 views

Im trying to plot in the function below to see the level curves, but it won't work.
I don't understand the error message, so i hope you can help
Udklip.PNG

2 replies

F
Fred_Kohlhepp23-Emerald I
23-Emerald I
September 17, 2013

If the radical evaluates to an imaginary number (x = 5 for example) the plot fails.

W
Werner_E25-Diamond I
25-Diamond I
September 17, 2013

Prime plotting capabilities are very limited. As Fred already pointed out Prime would refuse to plot anything if a single evaluated value would be a complex number. The same applies if a division by zero occurs.

One way out is to limit the values for x and y so the radical is positive --> -2.8 <= x,y <= 2.8.

Another approach would be to write a function which traps the division by zero and replaces complex values with NaN's (Not a Number).

Third possibility which comes to mind is to rewrite the function using an appropriate parameter representation if possible.

3DPlot1.png

I am not sure what you mean with level curves, but I guess you would need a contour plot. Contourplots dont work with NaN's so I set all complex values to 1. Unfortunately we cannot mix surfaceplot and countour in one graph or use colormaps as in Mathcad.

3Dplot2.png

P
ptc-50975041-VisitorAuthor
1-Visitor
September 17, 2013

hm, looks difficult. Can you refer to an other program which is more convenient?

I have 89-Nspire on my computer, but i cannot figure out how to do it.

W
Werner_E25-Diamond I
25-Diamond I
September 18, 2013

Here is another well known free program. Restricted in many respects but convenient and can be integrated into M$ Word, too. Its Microsoft Mathematics. No explicit countourplot, though - not sure if you need it.

M%24Math.png

Terms & ConditionsAccessibility statement