The `real' node type provides for event-driven simulation with double-precision floating point data. This type is useful for evaluating sampled-data filters and systems. The type implements all optional functions for User-Defined Nodes, including inversion and node resolution. For inversion, the sign of the value is reversed. For node resolution, the resultant value at a node is the sum of all values output to that node. The node is implemented as a user defined node in ngspice/src/xspice/icm/xtraevt/real.