Time series analysis is a statistical technique used to analyze data points collected over time. It's widely applied in finance, economics, weather forecasting, and more. Let's dive into the essentials!
Key Steps in Time Series Analysis
Data Collection
Gather historical data with timestamps. Example: stock prices or weather measurements.Data Preprocessing
- Check for missing values (
na.omit()
) - Convert to a time series object using
ts()
ortibble::as_tsibble()
- Normalize or scale data if needed
- Check for missing values (
Exploratory Analysis
Useplot()
to visualize trends, seasonality, and outliers.Modeling & Forecasting
Common approaches include:- ARIMA models (
forecast::auto.arima()
) - Exponential smoothing (
stats::ets()
) - Machine learning (e.g.,
prophet
for trend+seasonality)
- ARIMA models (
Evaluation
Compare predictions with actual values using metrics like MAE or RMSE.
Recommended Packages
tsibble
for tidy time series workflowsforecast
for advanced forecasting methodstseries
for financial time series analysisggplot2
for visualization
Example Code
# Load data
data <- read.csv("sales_data.csv")
data$date <- as.Date(data$date)
ts_data <- tsibble(data, index = date)
# Plot time series
ts_data %>%
ggplot(aes(x = date, y = sales)) +
geom_line() +
labs(title = "Monthly Sales Trend")
# Forecast using ARIMA
fit <- auto.arima(ts_data$sales)
forecast <- forecast(fit, h = 12)
autoplot(forecast) + labs(title = "ARIMA Forecast")
Expand Your Knowledge 🚀
- Learn about Time Series Forecasting with R for advanced techniques
- Explore Seasonal Decomposition in detail
- Check out R for Data Science for broader context