Please explain the method of steepest descent?

In summary, the method of steepest descent, also known as gradient descent, is a way to optimize functions using their gradient. It is similar to root finding algorithms for single variable equations, but is used for functions with two or more variables. It can also be used to approximate certain contour integrals. Further research is recommended to better understand and apply this method.
  • #1
wishfulthinking
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I am not understanding how to use the method of steepest descent aka the saddle point method. Any help would be appreciated, especially step-by-step explanation!
 
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  • #2
wishfulthinking said:
I am not understanding how to use the method of steepest descent aka the saddle point method. Any help would be appreciated, especially step-by-step explanation!

The method of steepest descent, or gradient descent, is a means of using the gradient of a function to perform an optimization:

http://en.wikipedia.org/wiki/Gradient_descent

You can find many more articles on such a procedure by Googling 'method of steepest descent' or 'method of gradient descent'.
 
  • #3
Thanks, I did Google the method, but I'm still not quite sure how to use it.
 
  • #4
wishfulthinking said:
Thanks, I did Google the method, but I'm still not quite sure how to use it.
Well, how familiar are you with using root finding algorithms on single variable equations, like finding the roots of polynomials?

Roughly speaking, steepest descent is an analogous method for functions of two or more variables, where you are trying to find the point at which the function reaches a local maximum or minimum.
 
  • #5
Thanks for taking the time out to reply. Specifically, I'm being asked to approximate an integral using the method. I've never learned this before and it's not in our textbook. My teacher said to look for outside resources, I'm just not understanding it and was hoping someone could explain it to me.
 
  • #6
wishfulthinking said:
Thanks for taking the time out to reply. Specifically, I'm being asked to approximate an integral using the method. I've never learned this before and it's not in our textbook. My teacher said to look for outside resources, I'm just not understanding it and was hoping someone could explain it to me.

Well, this technique is used to approximate certain contour integrals, as discussed here:

http://en.wikipedia.org/wiki/Method_of_steepest_descent

Since you know more about the type of integral you are trying to approximate, you're the one best suited to do the research. ;)
 

FAQ: Please explain the method of steepest descent?

What is the method of steepest descent?

The method of steepest descent is an optimization technique used to find the minimum of a multivariable function. It is also known as the gradient descent method or the steepest descent algorithm.

How does the method of steepest descent work?

The method of steepest descent works by iteratively moving in the direction of the steepest descent, or the direction of the negative gradient, of the function at a given point. This process continues until a minimum point is reached.

When is the method of steepest descent used?

The method of steepest descent is commonly used in machine learning and optimization problems where the goal is to find the minimum of a cost function. It is also used in physics and engineering to solve various problems.

What are the advantages of using the method of steepest descent?

The method of steepest descent is relatively easy to implement and can be applied to a wide range of problems. It also converges quickly to a local minimum and does not require the calculation of second derivatives.

What are the limitations of the method of steepest descent?

The method of steepest descent may not always find the global minimum and can get stuck in local minima. It also requires careful selection of the learning rate to ensure convergence. Additionally, it may take a large number of iterations to reach the minimum for highly non-convex functions.

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