10.3.1 The Projection Class

The projection object is primarily concerned with specifying where to receive connections from. Also, it determines what type of connections (and connection groups and connection specs) should be created:

PrjnSource from_type
Type of the projection source. This can have one of the following values:
  • NEXT: Receive connections from the next layer in network.
  • PREV: Receive connections from the previous layer in network.
  • SELF: Receive connections from the same layer this projection is in.
  • CUSTOM: Receive connections from the layer specified in the projection.
    Layer* from
    The layer this projection receives from. This is set automatically if from_type is not set to CUSTOM.
    ProjectionSpec_Sptr spec
    Points to the ProjectionSpec which controls the pattern of connectivity for this projection.
    TypeDef con_type
    The type of Connection to create when making connections.
    TypeDef con_gp_type
    The type of connection group to create when making connections.
    ConSpec_SPtr con_spec
    The connection specification to use for the connections.
  • The Projection class has a number of member functions, most of which have the same function as those defined on the Layer and the Network. Refer to section 10.2 Layers and Unit Groups and section 10.1 The Network Object for further details. The following are specific to projections:

    Copy_Weights(Projection* src)
    Copies the weights values from an equal sized projection to the weight values of the connections on this Projection.
    ApplyConSpec()
    Sets the conspec of the all the connections for this projection to the projection's con_spec without rebuilding them.