smesh/doc/examples/grouping_elements_ex01.py

# Create a Standalone Group

from mechanic import *

# Get ids of all faces with area > 100 
aFilter = smesh_builder.GetFilter(SMESH.FACE, SMESH.FT_Area, SMESH.FT_MoreThan, 100.)

anIds = mesh.GetIdsFromFilter(aFilter) 

# create a group consisting of faces with area > 100
aGroup1 = mesh.MakeGroupByIds("Area > 100", SMESH.FACE, anIds)

# create a group that contains all nodes from the mesh
aGroup2 = mesh.CreateEmptyGroup(SMESH.NODE, "all nodes")
aGroup2.AddFrom(mesh.mesh)


# ====================================
# Various methods of the Group object
# ====================================

aGroup = mesh.CreateEmptyGroup(SMESH.NODE, "aGroup")

# set/get group name
aGroup.SetName( "new name" )
print("name", aGroup.GetName())

# get group type (type of entities in the group, SMESH.NODE in our case)
print("type", aGroup.GetType())

# get number of entities (nodes in our case) in the group
print("size", aGroup.Size())

# check of emptiness
print("is empty", aGroup.IsEmpty())

# check of presence of an entity in the group
aGroup.Add([1,2]) # Add() method is specific to the standalone group
print("contains node 2", aGroup.Contains(2))

# get an entity by index
print("1st node", aGroup.GetID(1))

# get all entities
print("all", aGroup.GetIDs())

# get number of nodes (actual for groups of elements)
print("nb nodes", aGroup.GetNumberOfNodes())

# get underlying nodes (actual for groups of elements)
print("nodes", aGroup.GetNodeIDs())

# set/get color
import SALOMEDS
aGroup.SetColor( SALOMEDS.Color(1.,1.,0.));
print("color", aGroup.GetColor())

# ----------------------------------------------------------------------------
# methods specific to the standalone group and not present in GroupOnGeometry
# and GroupOnFilter
# ----------------------------------------------------------------------------

# clear the group's contents
aGroup.Clear()

# add contents of other object (group, sub-mesh, filter)
aGroup.AddFrom( aGroup2 )

# removes entities
aGroup.Remove( [2,3,4] )