Use to display the distribution of continuous variables. Boxplots are based upon a set of summary statistics that describe the center and spread of data. Boxplots are a very useful way for comparing data bewteen groups.
Box Plots – One Variable
- From an open JMP® data table, select Analyze > Distribution.
- Click on one or more continuous variables from Select Columns, and Click Y, Columns (continuous variables have blue triangles). Click OK.
- An outlier box plot is displayed by default next to the histogram (or above if horizontal layout is used).
- To display a quantile box plot, select the option from the red triangle for the variable.
The Outlier Box Plot shows the box, plus:
• IQR = the 3rd quartile minus the 1st quartile.
• Whiskers drawn to the furthest point within 1.5 x IQR from the box.
• Potential outliers (disconnected points).
• A red bracket defining the shortest half of the data (the densest region).
• A confidence diamond showing the mean (middle of the diamond) and the upper and lower bound of a 95% confidence interval for the population mean.
Box Plots – Two Variables
- Select Analyze > Fit Y by X.
- Click on a continuous variable from Select Columns, and Click Y, Response.
- Click on a categorical variable and click X, Factor (categorical variables have red or green bars). Click OK.
- The Oneway Analysis output window will display.
- Click on the red triangle, and select Display Options > Box Plots to display quantile box plots, or select Quantiles to display both box plots and a numeric table with the quantile values.
Notes: Box plots for one or more variables can also be generated from Graph > Graph Builder.
Visit Discovery JMP > Visualize Your Data, Basic Analysis > Distributions > Options for Continuous Variables, and Basic Analysis > Oneway Analysis in JMP Help to learn more.