mm_domain check contained points

[talledodiego]

This PR add methods to results objects to check if points (from load combinations) are contained within the strength domain.

• MM Interaction domain
• NM interaction domain
• 3D NMM interaction domain

The first case is the easiest: we have a given N, we compute the domain (that is a slice in the NMM with a plane orthogonal to N axis).
The second case seems easy. Actually it is trivial for the theta = 0, so with uniaxial bending about y axes (i.e. a longitudinal section of the 3d NMM domain). But in general when theta is different than 0 the plane figure is not longitudinal anymore so we have triplet of points N, My, Mz for defining the plane figure domain.

MM Interaction domain

The method contains has been included into the MM result object. This permit to do in efficient and fast way checks for one or a array of points with coordinates My, Mz.

Example:

contained = res.contains(My, Mz)

# Do the plot
fig, ax = plt.subplots(figsize=(8, 6))
ax.plot(res.m_y * 1e-6, res.m_z * 1e-6, "-o", markersize=3)
ax.set_xlabel(r"$M_y$ [kNm]")
ax.set_ylabel(r"$M_z$ [kNm]")
ax.axhline(0, color="k", linestyle="-", lw=0.75)
ax.axvline(0, color="k", linestyle="-", lw=0.75)
ax.scatter(My[contained]*1e-6, Mz[contained]*1e-6, color="g", marker="o", label="Inside point")
ax.scatter(My[~contained]*1e-6, Mz[~contained]*1e-6, color="r", marker="x", label="Outside point")

fig.tight_layout()

This for instance gives: