Posit AI Weblog: torch 0.11.0

torch v0.11.0 is now on CRAN! This weblog publish highlights among the modifications included
on this launch. However you may at all times discover the total changelog
on the torch web site.

Improved loading of state dicts

For a very long time it has been doable to make use of torch from R to load state dicts (i.e. 
mannequin weights) skilled with PyTorch utilizing the load_state_dict() operate.
Nonetheless, it was frequent to get the error:

Error in cpp_load_state_dict(path) :  isGenericDict() INTERNAL ASSERT FAILED at

This occurred as a result of when saving the state_dict from Python, it wasn’t actually
a dictionary, however an ordered dictionary. Weights in PyTorch are serialized as Pickle recordsdata – a Python-specific format just like our RDS. To load them in C++, with out a Python runtime,
LibTorch implements a pickle reader that’s in a position to learn solely a subset of the
file format, and this subset didn’t embody ordered dicts.

This launch provides help for studying the ordered dictionaries, so that you gained’t see
this error any longer.

Moreover that, studying theses recordsdata requires half of the height reminiscence utilization, and in
consequence additionally is far sooner. Listed below are the timings for studying a 3B parameter
mannequin (StableLM-3B) with v0.10.0:

system.time({
  x <- torch::load_state_dict("~/Downloads/pytorch_model-00001-of-00002.bin")
  y <- torch::load_state_dict("~/Downloads/pytorch_model-00002-of-00002.bin")
})

   consumer  system elapsed 
662.300  26.859 713.484 

and with v0.11.0

   consumer  system elapsed 
  0.022   3.016   4.016 

Which means that we went from minutes to only a few seconds.

Utilizing JIT operations

One of the vital frequent methods of extending LibTorch/PyTorch is by implementing JIT
operations. This enables builders to jot down customized, optimized code in C++ and
use it instantly in PyTorch, with full help for JIT tracing and scripting.
See our ‘Torch exterior the field’
weblog publish if you wish to be taught extra about it.

Utilizing JIT operators in R used to require bundle builders to implement C++/Rcpp
for every operator in the event that they wished to have the ability to name them from R instantly.
This launch added help for calling JIT operators with out requiring authors to
implement the wrappers.

The one seen change is that we now have a brand new image within the torch namespace, referred to as
jit_ops. Let’s load torchvisionlib, a torch extension that registers many various
JIT operations. Simply loading the bundle with library(torchvisionlib) will make
its operators obtainable for torch to make use of – it’s because the mechanism that registers
the operators acts when the bundle DLL (or shared library) is loaded.

As an illustration, let’s use the read_file operator that effectively reads a file
right into a uncooked (bytes) torch tensor.

torch_tensor
 137
  80
  78
  71
 ...
   0
   0
 103
... [the output was truncated (use n=-1 to disable)]
[ CPUByteType{325862} ]

We’ve made it so autocomplete works properly, such you could interactively discover the obtainable
operators utilizing jit_ops$ and urgent to set off RStudio’s autocomplete.

Different small enhancements

This launch additionally provides many small enhancements that make torch extra intuitive:

• Now you can specify the tensor dtype utilizing a string, eg: torch_randn(3, dtype = "float64"). (Beforehand you needed to specify the dtype utilizing a torch operate, resembling torch_float64()).

  torch_randn(3, dtype = "float64")

  torch_tensor
  -1.0919
   1.3140
   1.3559
  [ CPUDoubleType{3} ]

• Now you can use with_device() and local_device() to briefly modify the gadget
  on which tensors are created. Earlier than, you had to make use of gadget in every tensor
  creation operate name. This enables for initializing a module on a selected gadget:

  with_device(gadget="mps", {
    linear <- nn_linear(10, 1)
  })
  linear$weight$gadget

  torch_device(kind='mps', index=0)

• It’s now doable to briefly modify the torch seed, which makes creating
  reproducible applications simpler.

  with_torch_manual_seed(seed = 1, {
    torch_randn(1)
  })

  torch_tensor
   0.6614
  [ CPUFloatType{1} ]

Thanks to all contributors to the torch ecosystem. This work wouldn’t be doable with out
all of the useful points opened, PRs you created, and your arduous work.

In case you are new to torch and need to be taught extra, we extremely suggest the not too long ago introduced ebook ‘Deep Studying and Scientific Computing with R torch’.

If you wish to begin contributing to torch, be at liberty to succeed in out on GitHub and see our contributing information.

The complete changelog for this launch may be discovered right here.

Picture by Ian Schneider on Unsplash

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Quotation

For attribution, please cite this work as

Falbel (2023, June 7). Posit AI Weblog: torch 0.11.0. Retrieved from 

BibTeX quotation

@misc{torch-0-11-0,
  writer = {Falbel, Daniel},
  title = {Posit AI Weblog: torch 0.11.0},
  url = {},
  yr = {2023}
}