Struct RMSprop 

pub struct RMSprop { /* private fields */ }

RMSprop optimizer (Hinton, 2012).

Maintains a running average of squared gradients to normalize the update. Optionally supports momentum and weight decay.

Update rule (without momentum): v = alpha * v + (1 - alpha) * grad^2 param -= lr * grad / (sqrt(v) + eps)

With momentum: v = alpha * v + (1 - alpha) * grad^2 buf = momentum * buf + grad / (sqrt(v) + eps) param -= lr * buf

let mut optim = RMSprop::new(&model.parameters(), 0.01);
// Or with options:
let mut optim = RMSprop::builder(&model.parameters(), 0.01)
    .alpha(0.99)
    .momentum(0.9)
    .weight_decay(1e-4)
    .build();

Implementations

impl RMSprop

pub fn new(params: &[Parameter], lr: f64) -> Self

Create a new RMSprop optimizer with default parameters: alpha=0.99, eps=1e-8, weight_decay=0, momentum=0.

pub fn builder(params: &[Parameter], lr: f64) -> RMSpropBuilder

Create a builder for RMSprop with customizable options.

pub fn lr(&self) -> f64

Current learning rate.

Trait Implementations

impl Optimizer for RMSprop

fn lr(&self) -> f64

Current learning rate (group 0 for grouped optimizers).

fn step(&mut self) -> Result<()>

Perform a single optimization step using accumulated gradients.

fn zero_grad(&self)

Reset all parameter gradients to zero.

fn set_lr(&mut self, lr: f64)

Update the learning rate (all groups if grouped).

fn set_group_lr(&mut self, group: usize, lr: f64)

Set learning rate for a specific parameter group (0-indexed). Falls back to set_lr for single-group optimizers.

fn scale_lr(&mut self, factor: f64)

Multiply the learning rate by a factor (all groups).

impl Stateful for RMSprop

fn save_state<W: Write>(&self, w: &mut W) -> Result<()>

Serialize optimizer state (lr, momentum buffers, etc.) to a writer.

fn load_state<R: Read>(&mut self, r: &mut R) -> Result<()>

Restore optimizer state from a reader.

fn save_state_file(&self, path: &str) -> Result<()>

Save state to a file. Uses gzip compression if path ends with .gz.

fn load_state_file(&mut self, path: &str) -> Result<()>

Load state from a file. Detects gzip from .gz extension.