values : (V, ) array

Gives a measure for the maximum value of the data in the local region
        near each vertex. This can be used by visualization tools to apply
        a colormap to the mesh.

What is data here (this term is too general)? 

I saw that values.shape[0] is the same as vertices.shape[0]. Hence each value is associated to a vertex.
 How is it assigned to a vertex? How are these values related to the volume or to the equation F(x,y,z)=0? 
(I want to extract a triangulation of an implicit surface having this equation).

A second question is related to the coordinates of vertices.

When I plot the  trisurf defined by `vertices` and `faces` I notice 

that the x, y and z-range illustrated by tick values

is different from the real values. More precisely: if my surface has zmin=-1 and zmax=2,  on z-axis

this range is [5,11].  Is there a transformation that maps the vertices coordinates, as they are returned by 

`measure.marching_cubes` to real coordinates on my surface?

Thanks,

Eve