Geometric object = a set of points satisfying a given relationship(e.g. equations)
“Flat” = defined by linear equations
Linear equations:
-Can add and subtract variables and constants
-Can multiply a variable by a constant
Linear: x + 2y = 1, y/2 – 2z =x
Nonlinear: x^2 -1 = y, y/x = 3
Equations come from observed or modeled relationships between real-world quantities.
ML for trading
stock:A, B
Wa = proportion of portfolio invested in A
Wb = proportion of portfolio invested in B
0 < Wa, Wb < 1
β value = measure of correlation of a stock's price movements with market movement
β of portfolio = weighted average of individual components' β values
Wa + Wb = 1
B portfolio = 2Wb - Wa = 0
Variables: weights of the stocks
Constraints: equations representing physical realities or objectives
Lines in Two dimensions
Two pieces of info define a line
-basepoint x
-direction vector v
x(t) = x + tv
Ax + By = 0
(A and B not both 0)