Shorthand:

$minMaxScaler: <numeric expression>

Or extended:

$minMaxScaler: {
  input: <numeric expression>,
  min: <constant numeric expression>,
  max: <constant numeric expression>
}

Using the defaults for min and max (0 and 1 respectively), given a sequence of numbers in the window
X = x0, x1, … xn, this will calculate:

minMaxScaler(xi) =(xi -min(X)) / (max(X) -min(X))

Now adding parameters smin and smax, for the fully general case we get:

minMaxScaler(xi, smin, smax) =((xi -min(X)) / (max(X) -min(X))*(smax-smin) +smin

You can see that these new terms just adjust the value between 0 and 1 to be in the domain (smin, smax)