# R Howtos

## R R-Squared

## R Linear Regression

## R Model Fit

## R String

- Remove the First Character From a String in R
- Split String by Delimiter in R
- Remove Last Character From String in R

## R Factor

## R Date

## R Plot

- Create Custom Legend With ggplot in R
- Create Grouped Boxplots in R
- Create Histogram With ggplot in R
- Create Side by Side Boxplots in R
- Draw Legend Items With Different Colors in R
- Modify ggplot X Axis Tick Labels in R
- The scale_colour_discrete Function in R
- The scale_x_discrete Function in R
- The scale_y_continuous Function in R
- Add Transparent Rectangle to Boxplot in R
- Add a Line to a Plot With the Lines() Function in R
- Change Point Size in Graphs in R
- Label BoxPlot in R
- ylim() and xlim() in R
- Create Stacked Histogram in R
- Set Thickness of Plots in R
- Set Axis Limits in Ggplot2 R Plots

## R Loop

## R Data Frame

- Remove Duplicate Rows by Column in R
- Create a Large Data Frame in R
- Find Maximum Absolute Values by Row in Data Frame in R
- Merge Two Data Frames With Different Number of Rows in R
- Replace NA With Zero in R
- Count Number of Observations in R
- Count Number of Rows in R
- Combine Two Data Frames in R

## R Separate

## R Regex

- Use grepl to Find Matches for Any Character String in the R Character Vector
- Match Newline Characters in R Regex