Class CROperatorDivideVSDamped

java.lang.Object
org.ddogleg.chainrule.ops.CROperatorDivideVSDamped
All Implemented Interfaces:
CROperatorBackwardsJac<double[]>, CROperatorForward<double[]>
public class CROperatorDivideVSDamped extends Object implements CROperatorBackwardsJac<double[]>
Divides a vector by a damped scalar: a[i]/(beta + b). input[0] is the vector and input[1] is the scalar, which is expected to be at or above zero, so a beta > 0 keeps the denominator away from zero however small the scalar gets

  • Field Details

  • Constructor Details

    • CROperatorDivideVSDamped

      public CROperatorDivideVSDamped(int dof, double beta)

  • Method Details

    • forward

      public void forward(CRArray<double[]> output)
      Description copied from interface: CROperatorForward
      Performs forward pass of the function. Must have already updated CROperatorForward.setInput(int, CRArray).
      Specified by:
      forward in interface CROperatorForward<double[]>
      Parameters:
      output - (Output) Output vector. Modified.

    • jacobian

      public void jacobian(CRMatrix<double[]> dout, List<CRMatrix<double[]>> jacobianInputs)
      The quotient rule with the damping riding along in the denominator: the vector's Jacobian is 1/(beta + b) on the diagonal, and the scalar's is -a/(beta + b)^2 as a single column
      Specified by:
      jacobian in interface CROperatorBackwardsJac<double[]>
      Parameters:
      dout - (Input) Jacobian of output conditional on this function, computed from next layer.
      jacobianInputs - (Output) Storage for all the Jacobian inputs. All matrices must be pre-declared and included in the list. If a matrix is marked as invalid, then the jacobian is skipped for that input.

    • setInput

      public void setInput(int which, CRArray<double[]> input)
      Description copied from interface: CROperatorForward

      Specifies the value of an input's vector.

      The implementation can safely save the array input points at along with its offset. Neither the values at that offset nor the array itself will change until after CROperatorForward.forward(CRArray) or a derived function such as CROperatorBackwardsJac.jacobian(CRMatrix, List) has been called. The input reference itself cannot be saved: the caller is free to recycle the CRArray the moment the call returns, including pointing it at another offset.

      Specified by:
      setInput in interface CROperatorForward<double[]>
      Parameters:
      which - Which input
      input - The input's value. This reference can't be saved internally but the array and offset can be.

    • getInputSize

      public int getInputSize(int which)
      Description copied from interface: CROperatorForward
      Returns the specified input's vector size
      Specified by:
      getInputSize in interface CROperatorForward<double[]>

    • getInputCount

      public int getInputCount()
      Description copied from interface: CROperatorForward
      Number of inputs
      Specified by:
      getInputCount in interface CROperatorForward<double[]>

    • getOutputSize

      public int getOutputSize()
      Description copied from interface: CROperatorForward
      Returns the output vector's size
      Specified by:
      getOutputSize in interface CROperatorForward<double[]>

    • setSettings

      public void setSettings(Map<String,String> settings)
      Description copied from interface: CROperatorForward
      Reconfigures the block using the specified settings
      Specified by:
      setSettings in interface CROperatorForward<double[]>

    • getSettings

      public Map<String,String> getSettings()
      Encodes the damping only when it does something
      Specified by:
      getSettings in interface CROperatorForward<double[]>

    • getArrayType

      public Class<double[]> getArrayType()
      Description copied from interface: CROperatorForward
      Primitive data type for the array
      Specified by:
      getArrayType in interface CROperatorForward<double[]>