Frequently Asked Questions about R

Data Management

• How to Input data into R
• How can I read binary data into R?
• How can I write a binary data file by column?
• How can I write a binary data file by row?
• How can I sort my data in R?
• How can I format a string containing a date into R "Date" object?
• How can I get a table of basic descriptive statistics for my variables?
• How can I subset a data set?
• How can I identify the first and last observations within a group in R?
• How does R handle missing values?
• How does R handle date values?
• How can I reshape my data in R?
• How can I "collapse" my data in R?
• How can I convert from person-level to person-period?

R Interface

• How can I see what data sets are available when I started R?
• The very basics of R
• How can I save my data and graphs in a different format?
• How can I manage R packages?
• How can I time my code?

Graphics

• How can I overlay plots in a trellis graph?
• How can I make spaghetti plots?
• How can I visualize longitudinal data in ggplot2?
• How can I make individual growth curves in ggplot2?
• How can I explore different smooths in ggplot2?
• How can I do a scatterplot with regression line or any other lines?
• How can I change the angle of the value labels on my axes?
• How can I add features or dimensions to my bar plot?

Statistics

• How can I calculate Moran's I in R?
• How can I perform Mantel's test in R?
• How can I generate a variogram for spatial data in R?
• How can I generate a Venn diagram in R?
• How do I fit a variogram model to my spatial data in R using regression commands?
• How do I model a spatially autocorrelated outcome?
• How can I manage and plot social network data?
• How can I generate bootstrap statistics in R?
• How can I estimate the standard error of a transformed parameter in R using the delta method?
• How can I do post-hoc pairwise comparisons in R?
• How can I get Type III tests of fixed effects in R?
• How can I explain a continuous by continuous interaction?
• How can I perform seemingly unrelated regression in R?
• How can I test contrasts in R?

Random coefficient models

• Random coefficient poisson models
• Multivariate random coefficient model
• How can I perform mediation with multilevel data? (Method 2)

Miscellaneous

• How does R handle overlapping object names?