Class CROperatorClampLower

java.lang.Object
org.ddogleg.chainrule.ops.CROperatorClampLower
All Implemented Interfaces:
CROperatorBackwardsJac<double[]>, CROperatorForward<double[]>
public class CROperatorClampLower extends Object implements CROperatorBackwardsJac<double[]>

Holds a value at or above a floor: output = max(input, minimum).

Meant for a quantity the operators after it cannot accept, such as a depth that has gone negative while a solver was stepping around. Below the floor the derivative is zero, so what has been clamped stops asking to move and whatever else constrains it decides where it goes.

  • Constructor Details

    • CROperatorClampLower

      public CROperatorClampLower(int dof, double minimum)

  • Method Details

    • configure

      public void configure(int dof)
      Changes how many values it holds, which the settings do when one operator is made to match another

    • 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)
      One where the value passed through, zero where the floor decided it
      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[]> src)
      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
      src - The input's value. This reference can't be saved internally but the array and offset can be.

    • getSettings

      public Map<String,String> getSettings()
      Description copied from interface: CROperatorForward
      Retrieve a serialized description of the settings
      Specified by:
      getSettings 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[]>

    • 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[]>

    • getArrayType

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