Jul 20, 2018

## Intro to time series

##### Another way to remove seasonality from data in a series through time is to compare points that should be the same with respect to seasonal effects. For instance, there should be no seasonal effect if you plot only the temperature readings taken on January 1 of each year or only those taken on August 17 - which you just played with. Let’s look for a more holistic approach.

###### The temperature data has a seasonal component with a period of 365 days. Letting $$T_t$$ denote the temperature reading at time $$t$$, the following differences remove the seasonal component:

$\LARGE D_t = T_t - T_{t-365}$