Applying Analytics

90 Applying Analytics: A Practical Introduction

fit, and the term independent va riable

refers to the variable that the dependent

variable is a function of. In a 1-dimensional data set, ψ

i

is the dependent

variable and the measurement locations x

i

are the independent variable. I’ll

call the values output by the fit

¯

ψ

i

, to make clear that they are of the same

dimension a s ψ

i

and are measured at the same loc ations.

So, how is fitting actually done? In pr actice, w hen performing a fit, an

analyst first chooses a functional form

that gives the fit a broad s hap e, like a

parabola, a line, a sine wave, or a bell-curve. The functional form contains a

set of para