sp command

sp(nodeTag, dof, *dofValues)

This command is used to construct a single-point constraint object and add it to the enclosing LoadPattern.

nodeTag (int) tag of node to which load is applied.
dof (int) the degree-of-freedom at the node to which constraint is applied (1 through ndf)
dofValues (list (float)) ndf reference constraint values.


The dofValue is a reference value, it is the time series that provides the load factor. The load factor times the reference value is the constraint that is actually applied to the node.