Selcuk Disci

Time Series Forecasting: KNN vs. ARIMA

It is always hard to find a proper model to forecast time series data. One of the reasons is that models that use time-series data often expose to serial correlation. In this article, we will compare k nearest neighbor (KNN) regression which is a supervised machine learning method, with a more classical and stochastic process,Continue reading “Time Series Forecasting: KNN vs. ARIMA”

Model Selection: Adjusted Coefficient of Determination-Variance Tradeoff

WARNING: IN THE INTERVIEW AT 25/11/2020, THE MINISTER OF HEALTH OF THE REPUBLIC OF TURKEY CONFESSED THAT THE PEOPLE WHOSE TESTS(COVID-19) WERE POSITIVE BUT DID NOT SHOW THE SYMPTOMS, HAD NOT BEEN INCLUDED IN THE DAILY NEW CASES NUMBERS UNTIL NOW; IN THIS CASE THE DATASOURCE WE USED FOR TURKEY IS MISLEADING. I APOLOGIZE FORContinue reading “Model Selection: Adjusted Coefficient of Determination-Variance Tradeoff”

Turkey vs. Germany: COVID-19

Testing the Correlation between Time Series Variables

In the previous article, we examined trends and seasonality in gasoline prices in Turkey. This time we will examine whether the gasoline prices are related to the variables that are thought to affect gasoline prices the most by the Turkish people. One of the variables is the Brent crude oil prices that are averaged monthlyContinue reading “Testing the Correlation between Time Series Variables”

Trend Forecasting Models and Seasonality with Time Series

Gasoline prices always is an issue in Turkey; because Turkish people love to drive where they would go but they complain about the prices anyway. I wanted to start digging for the last seven years’ prices and how they went. I have used unleaded gasoline 95 octane prices from Petrol Ofisi which is a fuelContinue reading “Trend Forecasting Models and Seasonality with Time Series”