## What is Learning Rate

The stochastic gradient descent technique is used to develop deep learning neural networks.

Stochastic gradient descent is an optimization process that uses instances from the training data to evaluate the error for the current state, then updates the weights of the model using the back-propagation of errors procedure, sometimes known as simply backpropagation.

The step size, often known as the “learning rate,” is the amount by which the weights are changed during training.

The learning rate is an adjustable hyperparameter that has a modest positive value, usually between 0.0 and 1.0, and is used in the training of neural networks.

The weights of each node in the network are in charge. Instead of updating the weight with the whole amount, the learning rate is used to scale it.

This implies that a learning rate of 0.1, which is a popular default setting, means that each time the weights in the network are updated, they are modified by 0.1 * or 10% of the projected weight error.

## Influence of Learning Rate

The pace of speed at which the model learns is controlled by the hyperparameter. It regulates the amount of allocated error.

In a certain amount of training epochs, given a well-designed learning rate, the model will learn to best approximate the function given available resources.

A high learning rate helps the model to learn more quickly, but at the cost of a sub-optimal final set of weights. A slower learning rate may allow the model to acquire a more optimum or even globally optimal set of weights, but training will take much longer.

A learning rate that is too high will provide weight updates that are excessively big, and the model’s performance will swing throughout training epochs. Weights that diverge are thought to be the reason for oscillating performance. A slow learning rate may never converge or become trapped on an inferior solution.

- In the worst-case scenario, too-large weight changes may cause the weights to explode!

As a result, **we should avoid using a learning rate that is either too high or too low**. Nonetheless, we must build up the model so that a “good enough” collection of the mapping issue is described by the training dataset.

## Configuring

On your training dataset, it’s critical to select a decent value for the learning rate for your model.

In fact, the learning rate may be the most crucial hyperparameter to set for your model.

Indeed, if there are resources available to modify hyperparameters, a large portion of that time should be spent on optimizing the learning rate.

Unfortunately, the best learning rate for a given model on a specific dataset cannot be calculated analytically.

**A descent learning rate must be determined by trial and error.**

Many other variables of the optimization process will interact with the learning rate, and these relationships may be nonlinear. Nonetheless, lesser learning rates will need more training epochs in general. Larger learning rates, on the other hand, will need fewer training epochs. Furthermore, given the uncertain estimation of the error gradient, smaller batch sizes are better suited to smaller learning rates.

A decent beginning point for your challenge is 0.1 or 0.01, which is a standard default setting for the learning rate.

Diagnostic plots may be used to analyze how the model’s learning rate and learning dynamics are affected by the learning rate. Setting up the learning rate is difficult and time-consuming.

A sensitivity analysis of the learning rate for the chosen model, commonly known as a grid search, is another option. This may be used to explain the link between learning rate and performance as well as to highlight an order of magnitude where strong learning rates may be found.

Diagnostic plots may be used to analyze how the model’s learning rate and learning dynamics are affected by the learning rate. Setting up the learning rate is difficult and time-consuming.

A sensitivity analysis of the learning rate for the chosen model, commonly known as a grid search, is another option. This may be used to explain the link between learning rate and performance as well as to highlight an order of magnitude where strong learning rates may be found.

When plotted, the results of a sensitivity analysis generally take the shape of a “U,” with loss decreasing when the learning rate is reduced with a given number of training epochs until the model fails to converge, at which point loss suddenly increases again.