Steplr Pytorch 2 9 Documentation
Decays the learning rate of each parameter group by gamma every step_size epochs. Notice that such decay can happen simultaneously with other changes to the learning rate from outside this scheduler. When last_epoch=-1, sets initial lr as lr. optimizer (Optimizer) – Wrapped optimizer. step_size (int) – Period of learning rate decay. gamma (float) – Multiplicative factor of learning rate decay.
Default: 0.1. In the field of deep learning, adjusting the learning rate during the training process is a crucial technique. The learning rate determines the step size at which the model's parameters are updated. A large learning rate may cause the model to overshoot the optimal solution, while a small learning rate can lead to slow convergence. PyTorch provides various learning rate schedulers to address this issue, and StepLR is one of the most commonly used ones. This blog post will provide a comprehensive guide to understanding and using StepLR in PyTorch.
StepLR is a learning rate scheduler in PyTorch that decays the learning rate of each parameter group by a fixed factor every step_size epochs. The mathematical formula for StepLR is as follows: [ \text{lr}{epoch} = \text{lr}{0} \times \text{gamma}^{\lfloor \frac{\text{epoch}}{\text{step_size}} \rfloor} ] This scheduler is useful when you want to gradually reduce the learning rate during training to fine - tune the model and avoid overshooting the optimal solution. In the above code, we first import the necessary libraries. Then we define a simple linear model.
After that, we initialize an optimizer (Stochastic Gradient Descent in this case) and a StepLR scheduler. Finally, in the training loop, we call scheduler.step() at the end of each epoch to update the learning rate. There was an error while loading. Please reload this page. There was an error while loading. Please reload this page.
Decays the learning rate of each parameter group by gamma every step_size epochs. Notice that such decay can happen simultaneously with other changes to the learning rate from outside this scheduler. When last_epoch=-1, sets initial lr as lr. Return last computed learning rate by current scheduler. state_dict (dict) – scheduler state. Should be an object returned from a call to state_dict().
Returns the state of the scheduler as a dict. It contains an entry for every variable in self.__dict__ which is not the optimizer. Created On: Jun 13, 2025 | Last Updated On: Aug 24, 2025 torch.optim is a package implementing various optimization algorithms. Most commonly used methods are already supported, and the interface is general enough, so that more sophisticated ones can also be easily integrated in the future. To use torch.optim you have to construct an optimizer object that will hold the current state and will update the parameters based on the computed gradients.
To construct an Optimizer you have to give it an iterable containing the parameters (all should be Parameter s) or named parameters (tuples of (str, Parameter)) to optimize. Then, you can specify optimizer-specific options such as the learning rate, weight decay, etc. I understand that learning data science can be really challenging… …especially when you are just starting out. That’s why I spent weeks creating a 46-week Data Science Roadmap with projects and study resources for getting your first data science job. A Discord community to help our data scientist buddies get access to study resources, projects, and job referrals.
“Training a neural network is like steering a ship; too fast, and you might miss the mark; too slow, and you’ll drift away. Welcome to the first lesson of the Advanced Neural Tuning course. In this course, you will learn how to make your neural networks train more efficiently and achieve better results by using advanced optimization techniques. We will start with a key concept: learning rate scheduling. The learning rate is a crucial parameter in training neural networks. It controls how much the model's weights are updated during each step of training.
If the learning rate is too high, the model might not learn well and could even diverge. If it is too low, training can be very slow and might get stuck before reaching a good solution. Learning rate scheduling is a technique in which you change the learning rate during training instead of keeping it constant. This can help your model learn faster at the beginning and fine-tune its weights as training progresses. In this lesson, you will learn how to use a popular learning rate scheduler in PyTorch called StepLR. The StepLR scheduler is a simple but effective way to adjust the learning rate as your model trains.
In PyTorch, StepLR reduces the learning rate by a certain factor every fixed number of epochs. This helps the model make big updates early on and then smaller, more careful updates as it gets closer to a good solution. The two main parameters for StepLR are step_size and gamma. The step_size tells the scheduler how many epochs to wait before reducing the learning rate. The gamma parameter is the factor by which the learning rate is multiplied each time it is reduced. For example, if your initial learning rate is 0.1, your step_size is 10, and your gamma is 0.1, then after 10 epochs, the learning rate will become 0.01.
PyTorch is an optimized tensor library for deep learning using GPUs and CPUs. Features described in this documentation are classified by release status: Stable (API-Stable): These features will be maintained long-term and there should generally be no major performance limitations or gaps in documentation. We also expect to maintain backwards compatibility (although breaking changes can happen and notice will be given one release ahead of time). Unstable (API-Unstable): Encompasses all features that are under active development where APIs may change based on user feedback, requisite performance improvements or because coverage across operators is not yet complete. The APIs and performance characteristics of these features may change.
Created On: Apr 16, 2025 | Last Updated On: Apr 16, 2025 Integrating Custom Operators with SYCL for Intel GPU Supporting Custom C++ Classes in torch.compile/torch.export Accelerating torch.save and torch.load with GPUDirect Storage Getting Started with Fully Sharded Data Parallel (FSDP2) Interactive Distributed Applications with Monarch
People Also Search
- StepLR — PyTorch 2.9 documentation
- Understanding and Utilizing PyTorch StepLR - codegenes.net
- pytorch-image-models/timm/scheduler/step_lr.py at main - GitHub
- PyTorch torch.optim.StepLR English - Runebook.dev
- torch.optim — PyTorch 2.9 documentation
- Guide to Pytorch Learning Rate Scheduling - Medium
- Learning Rate Scheduling with PyTorch StepLR | CodeSignal Learn
- PyTorch documentation — PyTorch 2.9 documentation
- Developer Notes — PyTorch 2.9 documentation
- Welcome to PyTorch Tutorials — PyTorch Tutorials 2.9.0+cu128 documentation
Decays The Learning Rate Of Each Parameter Group By Gamma
Decays the learning rate of each parameter group by gamma every step_size epochs. Notice that such decay can happen simultaneously with other changes to the learning rate from outside this scheduler. When last_epoch=-1, sets initial lr as lr. optimizer (Optimizer) – Wrapped optimizer. step_size (int) – Period of learning rate decay. gamma (float) – Multiplicative factor of learning rate decay.
Default: 0.1. In The Field Of Deep Learning, Adjusting The
Default: 0.1. In the field of deep learning, adjusting the learning rate during the training process is a crucial technique. The learning rate determines the step size at which the model's parameters are updated. A large learning rate may cause the model to overshoot the optimal solution, while a small learning rate can lead to slow convergence. PyTorch provides various learning rate schedulers to...
StepLR Is A Learning Rate Scheduler In PyTorch That Decays
StepLR is a learning rate scheduler in PyTorch that decays the learning rate of each parameter group by a fixed factor every step_size epochs. The mathematical formula for StepLR is as follows: [ \text{lr}{epoch} = \text{lr}{0} \times \text{gamma}^{\lfloor \frac{\text{epoch}}{\text{step_size}} \rfloor} ] This scheduler is useful when you want to gradually reduce the learning rate during training t...
After That, We Initialize An Optimizer (Stochastic Gradient Descent In
After that, we initialize an optimizer (Stochastic Gradient Descent in this case) and a StepLR scheduler. Finally, in the training loop, we call scheduler.step() at the end of each epoch to update the learning rate. There was an error while loading. Please reload this page. There was an error while loading. Please reload this page.
Decays The Learning Rate Of Each Parameter Group By Gamma
Decays the learning rate of each parameter group by gamma every step_size epochs. Notice that such decay can happen simultaneously with other changes to the learning rate from outside this scheduler. When last_epoch=-1, sets initial lr as lr. Return last computed learning rate by current scheduler. state_dict (dict) – scheduler state. Should be an object returned from a call to state_dict().