# [SciPy-user] Simple plot problem

Guilherme P. de Freitas guilherme@gpfreitas....
Tue Feb 17 05:58:15 CST 2009

```> The plotting of a simple (x, y) -> function is definitely part of the
> intended use of mlab. I don't understand why you say that there isn't a
> single simple example, isn't the following acceptable:
> http://code.enthought.com/projects/mayavi/docs/development/html/mayavi/auto/mlab_helper_functions.html#enthought.mayavi.mlab.surf ?
>
> Did you not find this example. In which case we must make it clearer.

Sorry, I didn't express myself correctly. There should be a simple
example for each function. That is just the mlab.surf. For example,
in my case, I get the shrinked object in the mlab.plot3d function.
As there was no explanation of what was a valid input and the
example in the section was too complicated for me, I did not know if
I had the wrong input or if it is a problem in the software.

But, still, back to the original problem. Did you see the problem
with that code? I mean, test the code you sent me on the first
email. Don't you get a "shrinked" version of the parametric curve

http://archive.gpfreitas.com/misc/snapshot.png

This is what I get with your code. And I got this before too, trying
different approaches. I don't know why it is giving me this wrong
behavior. Again, what I need is:

1. the graph of the function f(x,y) = x**(0.3) * y**(0.7),  for x
and y in [0,3]

2. the parametric straight line (x, 2 - 2*x, 0)  for x in [0,1]

3. the parametric curve (x, 2 - 2*x, f(x, 2 - 2*x)) for x in [0,1]

The code you sent me in the first email does not correctly plot
the last two objects.  Objects 2 and 3 (which form a closed curve)