When working with a time series, one important thing we wish to determine is whether one series “causes” changes in another. In other words, is there a strong correlation between a time series and another given a number of lags? […]

Continue reading »# Category: Time Series

# Kalman Filter: Modelling Time Series Shocks with KFAS in R

We have already seen how time series models such as ARIMA can be used to make time series forecasts. While these models can prove to have high degrees of accuracy, they have one major shortcoming – they do not account […]

Continue reading »# ARIMA Models: Stock Price Forecasting with Python and R

ARIMA (Autoregressive Integrated Moving Average) is a major tool used in time series analysis to attempt to forecast future values of a variable based on its present value. For this particular example, I use a stock price dataset of Johnson […]

Continue reading »# Cross-Correlation of Currency Pairs In R (ccf)

When working with a time series, one important thing we wish to determine is whether one series “causes” changes in another. In other words, is there a strong correlation between a time series and another given a number of lags? […]

Continue reading »# Chow Test For Structural Breaks in Time Series

A Chow test is designed to determine whether a structural break in a time series exists. That is to say, a sharp change in trend in a time series that merits further study. For instance, a structural break in one […]

Continue reading »# Serial Correlation: Durbin-Watson and Cochrane-Orcutt Remedy

Serial correlation (also known as autocorrelation) is a violation of the Ordinary Least Squares assumption that all observations of the error term in a dataset are uncorrelated. In a model with serial correlation, the current value of the error term […]

Continue reading »# Stationarity and Cointegration in R (adf, egcm, pp, kpss)

When we refer to a time series as stationary, we mean to say that its mean, variance and autocorrelation are all consistent over time. Cointegration, on the other hand, is when we have two time series that are non-stationary, but […]

Continue reading »