# Why backpropogation is not enough!!

Backpropagation is a widely used algorithm for training artificial neural networks, but it is not a complete solution on its own. There are several reasons why backpropagation is not enough:

- Local minima: Backpropagation can get stuck in local minima, where the error is not zero, but it is not possible to decrease the error further by adjusting the weights. This can be a problem because the global minimum, which is the lowest possible error, may not be found.
- Vanishing gradients: When training deep neural networks, the gradients of the weights with respect to the error can become very small, which can make it difficult for the network to learn. This is known as the vanishing gradients problem.
- Exploding gradients: On the other hand, the gradients can also become very large, which can cause the weights to update too much and the error to diverge. This is known as the exploding gradients problem.
- Slow convergence: Backpropagation can be slow to converge, especially for large and complex datasets. This can make it difficult to train deep neural networks in a reasonable amount of time.

To address these issues, researchers have developed various techniques such as weight initialization, batch normalization, and optimizers like Adam, which can improve the performance of backpropagation and make it more effective for training neural networks.

There are several alternative algorithms for training artificial neural networks, including:

- Nelder-Mead: This is an optimization algorithm that uses a simplex search method to find the optimal solution. It does not require the computation of gradients, but it can be slower to converge than gradient-based algorithms.
- Particle swarm optimization: This is an optimization algorithm that uses a swarm of particles to explore the search space and find the optimal solution. It does not require the computation of gradients, but it can be sensitive to the choice of hyperparameters.
- Genetic algorithms: These are optimization algorithms that use principles of natural selection and evolution to find the optimal solution. They do not require the computation of gradients and can be effective for problems with a large search space, but they can be slower to converge than gradient-based algorithms.
- Simulated annealing: This is an optimization algorithm that is inspired by the annealing process in metallurgy and uses a random search process to find the optimal solution. It does not require the computation of gradients, but it can be slower to converge than gradient-based algorithms.
- Evolutionary strategies: These are optimization algorithms that use a population of solutions and apply evolutionary operations such as crossover and mutation to evolve the population towards the optimal solution. They do not require the computation of gradients and can be effective for problems with a large search space, but they can be slower to converge than gradient-based algorithms.