Generate a parametric surface with equations

[sriramakrishna turaga]

Hi All

I am new to this tool started learning I would like to generate a parametric surface from equations (please find the below link) and then fill it will solid. 

http://facstaff.susqu.edu/brakke/evolver/examples/periodic/periodic.html

Request you to help me with sample code and guidance. 

Thanks in advance

Sriramakrishna Turaga

[Roger Maitland]

Here is a bit of the following flag example: https://github.com/gumyr/cq_warehouse/blob/main/examples/projection.py

        def surface(amplitude, u, v):
            """Calculate the surface displacement of the flag at a given position"""
            return v * amplitude / 20 * cos(3.5 * pi * u) + amplitude / 10 * v * sin(
                1.1 * pi * v
            )

        # Note that the surface to project on must be a little larger than the faces
        # being projected onto it to create valid projected faces
        the_wind = (
            cq.Workplane("XY")
            .parametricSurface(
                lambda u, v: cq.Vector(
                    width * (v * 1.1 - 0.05),
                    height * (u * 1.2 - 0.1),
                    height * surface(wave_amplitude, u, v) / 2,
                ),
                N=40,
            )
            .thicken(0.5)
            .val()
        )

Cheers,

Roger