If the domain spans multiple minima, it will report back one of the minima, though not always the minimum one. In the right graph, with the values of the minimum, these are represented by:įor large enough - or well-placed enough - domains, MATALAB will find one of the local minima if the domain does not span a minimum, it will report back the minimum value at either the left or right boundary.

In the left graph, with the locations, these are represented by There are four local minima over the entire domain from -10 to 10. The black regoins indicate left and right values that will not work since 'Right' would be to the left of 'Left' there. The x axis represents the left boundary and the y axis represents the right boundary. XValue = 6.3834e+00 fValueSignWrong = - 5.6164e+00 fValue = 5.6164e+00 Where the Mins AreĪs noted above, if you give MATLAB a domain with multiple local minima, it will not always find the most-minimum minima here are two graphs showing 19,900 runs of fminbnd with different boundaries. The following examples show a method that will work regardless of how many input variables your function has or how you define your function - whether it is built-in, a variable containing an anonymous function, an anonymous function generated on the fly, or a. There are several different ways to present fminbnd with the specific function and variable.Įxamples Different Function Calls Most General Case

If there is no local minimum in the range, fminbnd will return one of the boundary values, depending on where the function is at its minimum value for the domain. If there are several, it should find one of them, though it may not find the most minimum of the minima. If there is a single local minimum over the domain, fminbnd should find it. The command can only find one minimum at a time and can only find minima based on one variable at a time. The fminbnd command in MATLAB can be used to find the value of a single parameter of a function that will minimize the value of the function on some bounded domain. The fminsearch command can find a single vector of values that will minimize a multi-dimensional function given some initial guess. The fminbnd command can find a single independent value that will minimize a one-dimensional function over a specific domain. This page discusses two different ways of getting MATLAB to find the minimum of a function (versus a data set) - fminbnd and fminsearch.

2.1.1.3 Single-Variable Built-in Functions and.

2.1.1.2 Single-Variable Anonymous Functions.

Find local min and max matlab