Finding stress values at each vertex

[bhaveshshrimali]

@sedaoturak

stress_2 = local_project(stress, V0)

This is a piecewise discontinuous function. I am not familiar with plotly.graph_objects but if you want to plot a discontinuous function at nodes, you are likely to encounter multiple values from the neighboring elements. The best way to visualize it would be using write_checkpoint and visualizing the result in Paraview