// NewEngine allocates and initializes a learning engine for the given corpus
// size. By default, users consider all elements equally.
func NewEngine(users, choices int) *Engine {
return &Engine{
X: gauss.Zero(users, choices),
Xp: gauss.Zero(users, choices),
Z: gauss.Zero(users, choices),
History: make([]Query, 0),
Nu: 1,
Lambda: 0.04,
Alpha: 1,
T: 1,
}
}
func (p *Engine) gradientLoss(samps []Query) gauss.Array {
result := gauss.Zero(p.X.Shape...)
before := p.hingeLoss(samps)
for i := range result.Data {
p.X.Data[i] += 0.0001
result.Data[i] = (p.hingeLoss(samps) - before) / 0.0001
p.X.Data[i] -= 0.0001
}
return result
}