variational function
nounUK /ˌveəriˈeɪʃənəl ˈfʌŋkʃən/
US /ˌveriˈeɪʃənəl ˈfʌŋkʃən/
A math rule that takes a whole path or shape and gives back a single number.
The variational function assigns a number to each curve, so we can find the curve that gives the smallest value.
OTHER MEANINGS
2. A function whose input is itself a function, used in optimization problems.
The variational function measures the cost of each possible path between two points.
3. In physics, a quantity that assigns an energy value to a field configuration.
The variational function for the system reaches its minimum at the true field.
4. A mapping used to compare different trial solutions in approximation methods.
We minimized the variational function to pick the best approximate wavefunction.