MCordingley\Regression\Algorithm\GradientDescent\Schedule\Adam::update PHP Method

    public function update(array $gradient)
    {
        if (!$this->means) {
            $this->means = array_fill(0, count($gradient), 0.0);
            $this->variances = array_fill(0, count($gradient), 0.0);
        }
        foreach ($gradient as $i => $slope) {
            $this->means[$i] = $this->meanBeta * $this->means[$i] + (1.0 - $this->meanBeta) * $slope;
            $this->variances[$i] = $this->varianceBeta * $this->variances[$i] + (1.0 - $this->varianceBeta) * pow($slope, 2);
        }
        $this->iteration++;
        $this->gradient = $gradient;
    }

 public function testStep()
 {
     $schedule = new Adam(0.01, 1.0E-8, 0.9, 0.999);
     $schedule->update([5.0]);
     $schedule->update([5.0]);
     static::assertEquals(0.0019999999959999857, $schedule->step(0));
 }