Interactive Plotting

When generating geometry from scratch within MAPDL, it is often necessary to plot the geometry (e.g. keypoints, lines, areas, volumes), and PyMAPDL supports plotting basic CAD using VTK. The Mapdl class leverages the existing MAPDL commands (e.g. Mapdl.kplot(), Mapdl.vplot(), Mapdl.eplot()) and transfers the geometry to Python to visualize it. These commands rely on the function ansys.mapdl.core.plotting.general_plotter(). Combined with the MAPDL geometry commands, you can generate and visualize geometry from scratch without opening the GUI using open_gui().

Line Plotting

Plot lines within Python using Mapdl.lplot().

>>> from ansys.mapdl.core import launch_mapdl
>>> mapdl = launch_mapdl()

Create a rectangle with a few holes

>>> mapdl.prep7()
>>> rect_anum = mapdl.blc4(width=1, height=0.2)

Create several circles in the middle in the rectangle

>>> for x in np.linspace(0.1, 0.9, 8):
...    mapdl.cyl4(x, 0.1, 0.025)

Generate a line plot

>>> mapdl.lplot(color_lines=True, cpos='xy')

Line Plot from MAPDL using PyMAPDL and Pyvista

Area and Volume Plotting

More complex geometry can be obtained using boolean operations and can be visualized using Mapdl.vplot(). In this example, we cut the initial area with the 8 circles and then extrude it.

>>> plate_holes = mapdl.asba(rect_anum, 'all')

Extrude this area

>>> mapdl.vext(plate_holes, dz=0.1)
>>> mapdl.vplot()

Volume Plot from MAPDL using PyMAPDL and Pyvista

Node and Element Plotting

Nodes and elements can also be plotted directly from the instance of Mapdl. We continue the example by defining some element types, meshing, and displaying the mesh.

>>> mapdl.et(1, 'SOLID186')
>>> mapdl.vsweep('ALL')
>>> mapdl.esize(0.1)
>>> mapdl.eplot()

Element Plot from MAPDL using PyMAPDL and Pyvista

Plotting Non-Interactively using MAPDL

You can also plot using MAPDL’s native plotting tools. To use the native tools, pass vtk=False when running plotting commands such as Mapdl.aplot, Mapdl.eplot, etc.. Plots will be generated within MAPDL and then shown using matploblib.

Start PyMAPDL

>>> from ansys.mapdl.core import launch_mapdl
>>> mapdl = launch_mapdl()

Create a square area using keypoints

>>> mapdl.prep7()
>>> mapdl.k(1, 0, 0, 0)
>>> mapdl.k(2, 1, 0, 0)
>>> mapdl.k(3, 1, 1, 0)
>>> mapdl.k(4, 0, 1, 0)
>>> mapdl.l(1, 2)
>>> mapdl.l(2, 3)
>>> mapdl.l(3, 4)
>>> mapdl.l(4, 1)
>>> mapdl.al(1, 2, 3, 4)

Set the view to “isometric”

>>> mapdl.view(1, 1, 1, 1)
>>> mapdl.pnum('kp', 1)  # enable keypoint numbering
>>> mapdl.pnum('line', 1)  # enable line numbering

Each of these will create a matplotlib figure and pause execution

>>> mapdl.aplot(vtk=False)
>>> mapdl.lplot(vtk=False)
>>> mapdl.kplot(vtk=False)

Area Plot from MAPDL displayed using matploblib

For more details on the plotting functions, see Plotting.

Plotting Keyword Options

When using vtk=True (default True), all the MAPDL plotting methods allow you to enter in additional keyword arguments to better control the plot. For example, you can automatically generate a screenshot of an area plot or element plot with:

>>> mapdl.aplot(savefig='aplot.png')
>>> mapdl.eplot(savefig='eplot.png')

You can also control the camera position with the cpos when you want to view from a standard viewing direction (for example view the XY plane with cpos='xy'.

>>> mapdl.eplot(cpos='xy')

For all general plotting options, see ansys.mapdl.core.plotting.general_plotter().

Plotting Boundary Conditions

Warning

This feature is still on beta so its functionalities and stability are limited. Please check the documentation regarding the allowed boundary conditions and targets.

It is possible to plot the boundary conditions applied on the model by specifying plot_bc=True in the plotting functions such as Mapdl.nplot().

>>> mapdl.nplot(
...     plot_bc=True,
...     plot_labels=True,
...     savefig=f'bc_plot.png',
...     bc_labels="mechanical"
... )

Mechanical boundary conditions Forces (arrows) and displacements (cones)

Note

Since the boundary conditions can only target nodes at the moment, you can only use plot_bc as an argument in the function Mapdl.nplot().

Boundary conditions demonstration