AdaHessian 🚀
Unofficial implementation of the AdaHessian optimizer. Created as a drop-in replacement for any PyTorch optimizer – you only need to set create_graph=True in the backward() call and everything else should work
Our version supports multiple param_groups, distributed training, delayed Hessian updates and more precise approximation of the Hessian trace.
Usage
from ada_hessian import AdaHessian
...
model = YourModel()
optimizer = AdaHessian(model.parameters())
...
for input, output in data:
optimizer.zero_grad()
loss = loss_function(output, model(input))
loss.backward(create_graph=True) # this is the important line! 🧐
optimizer.step()
...Documentation
AdaHessian.__init__
| Argument | Description |
|---|---|
params (iterable) |
iterable of parameters to optimize or dicts defining parameter groups |
lr (float, optional) |
learning rate (default: 0.1) |
betas((float, float), optional) |
coefficients used for computing running averages of gradient and the squared hessian trace (default: (0.9, 0.999)) |
eps (float, optional) |
term added to the denominator to improve numerical stability (default: 1e-8) |
weight_decay (float, optional) |
weight decay (L2 penalty) (default: 0.0) |
hessian_power (float, optional) |
exponent of the hessian trace (default: 1.0) |
update_each (int, optional) |
compute the hessian trace approximation only after this number of steps (to save time) (default: 1) |
n_samples (int, optional) |
how many times to sample z for the approximation of the hessian trace (default: 1) |
average_conv_kernel (bool, optional) |
average out the hessian traces of convolutional kernels as in the original paper (default: false) |
AdaHessian.step
Performs a single optimization step.
| Argument | Description |
|---|---|
closure (callable, optional) |
a closure that reevaluates the model and returns the loss (default: None) |