Line Plot

Use Line Plot to compare response patterns of a function or a series. You can create a line plot with symbols or without symbols, depending on the number of groups and length of series that you want to compare.

In This Topic

Summarized variables (optional)
Categorical variables
Layout
Group variable
By variables
Display symbols
Display function as percent of total

For information about data considerations, examples, and interpretation, go to Overview for Line Plot.

Summarized variables (optional)

Enter a column that defines the points in the line chart.

Function

From Function, select the function of the Summarized variables. For example, if you select Maximum, Minitab defines the color for the graph based on the maximum value of the summarized variables. If you enter a text column in Summarized variables, you can only select Percent equal to specified values, Number of nonmissing values, or Number of missing values.

Some options require you to enter additional values.

Percentile: If you select Percentile, you must enter a value in Percentile value. The value must be between 0 and 100. Minitab uses the value you enter to define the color gradient in the graph. For example, if you enter 50, Minitab uses the 50th percentile to define the color gradient for each point on the graph.
Percent between two values: If you select Percent between two values, you must enter numeric values in First value and Second value. The value you enter for First value must be less than or equal to the value you enter for Second value. Minitab defines the color gradient for the graph based on the percentage of observations that is between the two values.
Percent equal to specified values: If you select Percent equal to specified values, you must enter one or more values in Values. The values must be the same type of data as the column you entered in Summarized variables. Minitab defines the color gradient for the graph based on the percentage of observations that is equal to the values that you enter.

Categorical variables

Enter a categorical variable that defines the x axis.

Layout

When you enter multiple Summarized variables, you can choose one of the following layout options.

Separate graph for each summarized variable: Minitab creates a separate line plot for each column in Summarized variables.
Overlay summarized variables: Multiple summarized variables are overlaid on the same graph. When you select this option, you can also specify the Legend groups. Select Categories from legend groups to have the groups of the Continuous variable form the legend and the columns you specify in Summarized variables form the x-axis. Select Summarized variables form legend groups to have the columns you specify in Summarized variables form the legend and the groups of the Continuous variable form the x-axis.

Group variable

Enter a variable that defines the groups. Group labels are shown in the graph legend.

By variables

Enter one or more grouping variables in By variables to create a separate plot for each level of the grouping variables. The columns that you enter must be the same length as the columns in Continuous variable and Summarized variables. The y-scales for each variable are the same across the multiple plots.

Show all combinations

When you enter multiple By variables, Minitab enables the Show all combinations checkbox. Select this option to create a separate plot for each combination of groups created by the By variables. If you do not select this option, Minitab creates a plot for each group of each By variable.

For example, the first By variable has 2 groups, Male and Female, and the second By variable has 2 groups, Employed and Unemployed. If you select Show all combinations, Minitab creates 4 separate plots for the combinations of Male/Employed, Male/Unemployed, Female/Employed, and Female/Unemployed. If you do not select Show all combinations, Minitab creates 4 separate plots for Male, Female, Employed, and Unemployed.

Display symbols

Select to display a symbol at each point on the x-axis. If you do not select this option, the graph displays only the lines.

Display function as percent of total

Select this option to change the Y-scale type to percent.