ntal data is very likely contaminated by noise, the basic principle
almost all regression analysis algorithms is what is called
g random observations to unknown truth, i.e., the mean of the
ons. All regression analysis approaches therefore have the same
i.e., “regress to mean”. In a simple experiment, it is assumed that
ervations are composed of a variation due to sample preparation
hnique error and data collection error. The error is assumed to be
and mostly follow a Gaussian distribution. Regressing these
ll finally lead the answer to the mean of these observations.
errors of a collected data set are assumed to follow a Gaussian
on, the mean of these observations is the true value. The
d of the Gaussian errors of N observed data is defined as below,
is the nth data point, ߪଶ stands for the variance of the data, ߤ is
own truth, i.e., the mean,
ࣦൌሺ2ߨሻିே/ଶෑexp ቆെ
ሺݔെߤሻଶ
2ߪଶ
ቇ
ே
ୀଵ
ying the negative logarithm to this likelihood function leads to the
g equation,
െlogࣦൌሺݔെߤሻଶ
ே
ୀଵ
ܥ
rivative is shown below,
∂ሺെlogࣦሻ
߲ߤ
ൌݔ
ே
ୀଵ
െܰߤ
ng this derivative leads to the estimated mean as shown below,
ߤ̂ ൌ1
ܰݔ
ே
ୀଵ