Re:A Cookbook for Machine Learning: Vol 1
by pedrosorio on Friday November 17, 2017 @03:46AM
(#15720269)
Notation is notation. I think it's hard to come up with a single guide because a lot of conventions depend on the area.
In the context of optimization, a star refers to the value of the variable that minimizes (or maximizes) a function you're interested in.
You will also see a hat over a variable (https://en.wikipedia.org/wiki/Hat_operator#Estimated_value) sometimes (from statistics) which is an estimate of some quantity from data (and that estimate may be obtained by minimizing a function - solving an optimization problem)
By the way, this is the first result when googling argmin: https://en.wikipedia.org/wiki/Arg_max
This isn't a formula that is 'true', it's a minimally specified program.
It takes a function g, and returns the values of it's arguments (theta and psi) that minimize the function g.
Re:A Cookbook for Machine Learning: Vol 1
by master_yoda_1 on Friday November 17, 2017 @01:36PM
(#15724694)
This might help
https://en.wikipedia.org/wiki/List_of_mathematical_symbols
θ∗,ψ∗←argminθ,ψg(θ,ψ)
With no prior explanation and say, yep, now that you put it that way, it's true?