step method

@override void step()

Performs a single optimization step according to the Adagrad update rule.

Implementation

@override
void step() {
  for (Tensor param in parameters) {
    dynamic gSum = _gSquaredSum[param]!;
    if (param.value is Vector) {
      Vector valVec = param.value as Vector;
      Vector gradVec = param.grad as Vector;
      Vector gSumVec = gSum as Vector;
      for (int i = 0; i < valVec.length; i++) {
        gSumVec[i] += pow(gradVec[i], 2);
        valVec[i] -= learningRate * gradVec[i] / (sqrt(gSumVec[i]) + epsilon);
      }
    } else if (param.value is Matrix) {
      Matrix valMat = param.value as Matrix;
      Matrix gradMat = param.grad as Matrix;
      Matrix gSumMat = gSum as Matrix;
      for (int r = 0; r < valMat.length; r++) {
        for (int c = 0; c < valMat[0].length; c++) {
          gSumMat[r][c] += pow(gradMat[r][c], 2);
          valMat[r][c] -= learningRate * gradMat[r][c] / (sqrt(gSumMat[r][c]) + epsilon);
        }
      }
    }
  }
}