matlab mapminmax

The `mapminmax` function in MATLAB is used to normalize data to a specified range. It maps the input data to a range between -1 and 1, or between 0 and 1, depending on the specified range. This function is commonly used in machine learning and data analysis applications to scale the input data to a common range, so that the data can be compared and analysed more easily.

The syntax of the `mapminmax` function is:

[y, settings] = mapminmax(x, ymin, ymax)

where:
- `x`: the input data matrix or vector
- `ymin`: the minimum value of the output range (default is -1)
- `ymax`: the maximum value of the output range (default is 1)
- `y`: the normalized output data matrix or vector
- `settings`: a structure containing the scaling parameters used to normalize the data, which can be used later to normalize new data using the same scaling parameters.

Here is an example of how to use the `mapminmax` function to normalize a matrix of data:

data = [1, 2, 3; 4, 5, 6; 7, 8, 9];
[y, settings] = mapminmax(data);

% display the normalized data and the scaling parameters
disp(y);
disp(settings);

In this example, the `mapminmax` function normalizes the input data matrix `data` to the default range of -1 to 1, and returns the normalized data in the output matrix `y`. The `settings` structure contains the scaling parameters used to normalize the data, which can be used later to normalize new data using the same scaling parameters.