SGPLOT Procedure

VBOX Statement

Creates a vertical box plot that shows the distribution of your data.
Interaction: The VBOX statement cannot be used together with other plot statements in the SGPLOT procedure. Box plots can be overlaid with other box plots. However, overlaid box plots must have the same category variables.
About Box Plots

Syntax

VBOX analysis-variable </ option(s)>;

Summary of Optional Arguments

Box options
specifies the width of the box.
specifies the shape of the whisker cap lines.
specifies that a connect line joins a statistic from box to box.
specifies the appearance of the lines that connect multiple boxes.
specifies an amount to offset all boxes from the discrete tick marks.
specifies that the whiskers can extend to the maximum and minimum values for the analysis variable, and that outliers are not identified.
specifies whether the boxes are filled with color.
specifies the appearance of the fill for the boxes.
specifies the appearance of the box outlines.
specifies the appearance of the marker that represents the mean in the box.
specifies the appearance of the line that represents the median.
hides the cap lines for the whiskers.
hides the mean marker.
hides the median line.
hides the outliers from the plot.
specifies that the boxes be notched.
specifies the appearance of the marker that represents the outliers.
specifies the appearance of the whisker and cap lines.
Group options
specifies the cluster width as a ratio of the midpoint spacing.
specifies a variable that is used to group the data.
specifies how to display grouped boxes.
specifies the ordering of boxes within a group.
Label options
adds data labels for the outlier markers.
specifies the appearance of the labels in the plot when you use the DATALABEL= option.
specifies that only the far outliers have data labels.
Plot options
specifies the value of the ID variable in an attribute map data set.
specifies the category variable for the plot.
specifies how many times observations are repeated for computational purposes.
specifies a label that identifies the box plot in the legend.
processes missing values as a valid category value and creates a box for it.
specifies a name for the plot.
specifies a method for computing the percentiles for the plot.
relocates outlier points that have identical values to prevent overlapping.
specifies the degree of transparency for the plot.
assigns the category variable to the secondary (top) horizontal axis.
assigns the response variable to the secondary (right) vertical axis.

Required Argument

analysis-variable
specifies the analysis variable for the plot. If you do not specify the CATEGORY= option, then one box is created for the analysis variable.

Optional Arguments

ATTRID= variable
specifies the value of the ID variable in an attribute map data set. You specify this option only if you are using an attribute map to control visual attributes of the graph. For more information, see Using SG Attribute Maps to Control Visual Attributes.
BOXWIDTH= numeric-value
specifies the width of the box. Specify a value between 0.0 (0% of the available width) and 1.0 (100% of the available width).
Default:0.4

When GROUP is specified, the default box width is 0.6.

CAPSHAPE= BRACKET | LINE | SERIF
specifies the shape of the whisker cap lines. Specify one of the following values:
BRACKET
displays a straight line with brackets.
LINE
displays a straight line.
SERIF
displays a short straight line.
CATEGORY= category-variable
specifies the category variable for the plot. A box plot is created for each distinct value of the category variable.
If you explicitly set the category axis type to LINEAR and use a numeric category variable, the box plot becomes an interval plot. Otherwise, the box plot is discrete.
CLUSTERWIDTH= numeric-value
specifies the cluster width as a ratio of the midpoint spacing. Specify a value from 0.1 (narrowest) to 1.0 (widest).
Default:0.7
Interaction:This option is applicable only when a GROUP is in effect and the category axis is discrete.
CONNECT= MEAN | MEDIAN | Q1 | Q3 | MIN | MAX
specifies that a connect line joins a statistic from box to box.
Interaction:This option applies only when the CATEGORY option is used to generate multiple boxes.
Tip:You can use the CONNECTATTRS option to specify attributes for the connect line.
CONNECTATTRS= style-element <(options)> | (options)
specifies the appearance of the lines that connect multiple boxes. You can specify the appearance by using a style element or by using suboptions. If you specify a style element, you can also specify suboptions to override specific appearance attributes.
Here is an example that specifies a style element: CONNECTATTRS=GraphData3
options can be one or more of the following:
COLOR= color
specifies the color of the line. You can specify colors using the same color schemes that are supported by SAS/GRAPH software. For more information, see Color-Naming Schemes in SAS/GRAPH: Reference.
Default:For ungrouped data, the default color is specified by the ContrastColor attribute of the GraphConnectLine style element in the current style. For grouped data, the default color is specified by the ContrastColor attribute of the GraphData1 ... GraphDatan style elements in the current style.
PATTERN= line-pattern
specifies the line pattern for the line. You can reference SAS patterns by number or by name. For a list of line patterns, see Line Patterns.
Default:For ungrouped data, the default line pattern is specified by the LineStyle attribute of the GraphConnectLine style element in the current style. For grouped data, the default line pattern is specified by the LineStyle attribute of the GraphData1 ... GraphDatan style elements in the current style.
THICKNESS= n <units>
specifies the thickness of the line. You can also specify the unit of measure. The default unit is pixels. For a list of measurement units that are supported, see Units of Measurement.
Default:For ungrouped data, the default line thickness is specified by the LineThickness attribute of the GraphConnectLine style element in the current style. For grouped data, the default line thickness is specified by the LineThickness attribute of the GraphData1 ... GraphDatan style elements in the current style.
Here is an example expression:
CONNECTATTRS=(Color= "light green" Pattern= MediumDash Thickness= 4)
Default:The default style element is GraphConnectLine.
Interactions:This option takes effect only if the CONNECT= option is also specified.

This option is ignored if the GROUP= option is also specified.

DATALABEL <= variable>
adds data labels for the outlier markers. If you specified a variable, then the values for that variable are used for the data labels. If you did not specify a variable, then the values of the analysis variable are used.
Note:This option has no effect unless the plot contains outlier points.
DATALABELATTRS= style-element <(options)> | (options)
specifies the appearance of the labels in the plot when you use the DATALABEL= option. You can specify the appearance by using a style element or by using suboptions. If you specify a style element, you can also specify suboptions to override specific appearance attributes.
Here is an example that specifies a style element: DATALABELATTRS=GraphLabelText
options can be one or more of the following:
COLOR= color
specifies the color of the label characters. You can specify colors using the same color schemes that are supported by SAS/GRAPH software. For more information, see Color-Naming Schemes in SAS/GRAPH: Reference.
Default:For ungrouped data, the default color is specified by the Color attribute of the GraphDataText style element in the current style. For grouped data, the default color is specified by the ContrastColor attribute of the GraphData1 ... GraphDatan style elements in the current style.
FAMILY= “font-family
specifies the font family for the label characters. The SAS ODS styles use TrueType system fonts. For more information, see TrueType Fonts Supplied by SAS in SAS Language Reference: Concepts.
Default:The default font family is specified by the FontFamily attribute of the GraphDataText style element in the current style.
SIZE= n <units>
specifies the font size of the label characters. You can also specify the unit of measurement. The default unit is pixels. For a list of measurement units that are supported, see Units of Measurement.
Default:The default font size is specified by the FontSize attribute of the GraphDataText style element in the current style.
STYLE= ITALIC | NORMAL
specifies whether the label characters are italic (ITALIC) or normal (NORMAL).
Default:The default font style is specified by the FontStyle attribute of the GraphDataText style element in the current style.
WEIGHT= BOLD | NORMAL
specifies whether the label characters are bold (BOLD) or normal (NORMAL).
Default:The default font weight is specified by the FontWeight attribute of the GraphDataText style element in the current style.
Here is an example expression:
DATALABELATTRS=(Color=Green Family=Arial Size=8 Style=Italic Weight=Bold)
Default:The default style element is GraphDataText.
Interaction:This option has no effect unless the DATALABEL option is also specified.
DISCRETEOFFSET= numeric-value
specifies an amount to offset all boxes from the discrete tick marks. Specify a value from -0.5 (left offset) to +0.5 (right offset). If you specify a value outside of this range, an error message appears in the SAS log and the graph is not produced.
Default:0.0 (no offset)
EXTREME
specifies that the whiskers can extend to the maximum and minimum values for the analysis variable, and that outliers are not identified. When you do not specify the EXTREME option, the whiskers cannot be longer than 1.5 times the length of the box.
FILL | NOFILL
specifies whether the boxes are filled with color. The FILL option shows the fill color. The NOFILL option hides the fill color.
Default:FILL
FILLATTRS= style-element | (COLOR= color)
specifies the appearance of the fill for the boxes. You can specify the color of the fill by using a style element or by using the COLOR= suboption. You can specify colors using the same color schemes that are supported by SAS/GRAPH software. For more information, see Color-Naming Schemes in SAS/GRAPH: Reference.
Default:For ungrouped data, the default color is specified by the Color attribute of the GraphDataDefault style element in the current style.

For grouped data, the default color is specified by the ContrastColor attribute of the GraphData1 ... GraphDatan style elements in the current style.

Interaction:This option has no effect if you also specify the NOFILL option.
FREQ= numeric-variable
specifies how many times observations are repeated for computational purposes. specifies that each observation is repeated n times for computational purposes, where n is the value of the numeric variable. If n is not an integer, then it is truncated to an integer. If n is less than 1 or missing, then it is excluded from the analysis.
Interaction:If your plot is overlaid with other categorization plots, then the first FREQ variable that you specified is used for all of the plots.
GROUP= variable
specifies a variable that is used to group the data. The plot elements for each group value are automatically distinguished by different visual attributes.
GROUPDISPLAY= CLUSTER | OVERLAY
specifies how to display grouped boxes.
CLUSTER
the boxes are drawn adjacent to each other.
OVERLAY
all the boxes for a given group value are drawn at the exact coordinate and might overlap. Each group is represented by unique visual attributes derived from the GraphData1... GraphDatan style elements in the current style.
Default:CLUSTER for a discrete category axis

OVERLAY for a linear axis

Restriction:GROUPDISPLAY=CLUSTER can take effect only when the category axis is discrete.
Interaction:This option is ignored unless GROUP= is specified.
GROUPORDER= ASCENDING | DESCENDING | DATA
specifies the ordering of boxes within a group.
ASCENDING
displays each group in ascending group value.
DESCENDING
displays each group in descending group value.
DATA
displays each group in data order of the group variable.
Interaction:This option is ignored unless GROUP= is specified.
LABELFAR
specifies that only the far outliers have data labels. Far outliers are points whose distance from the box is more than three times the length of the box.
Note:This option has no effect if you do not specify the DATALABEL option, or if there are no far outliers.
LEGENDLABEL= “text-string
specifies a label that identifies the box plot in the legend. By default, the label of the analysis variable is used.
LINEATTRS= style-element <(options)> | (options)
specifies the appearance of the box outlines. You can specify the appearance by using a style element or by using suboptions. If you specify a style element, you can also specify suboptions to override specific appearance attributes.
Here is an example that specifies a style element: LINEATTRS=GraphData3
For more information about style elements, see Style Elements for Use with ODS Graphics.
options can be one or more of the following:
COLOR= color
specifies the color of the line. You can specify colors using the same color schemes that are supported by SAS/GRAPH software. For more information, see Color-Naming Schemes in SAS/GRAPH: Reference.
Default:For ungrouped data, the default color is specified by the ContrastColor attribute of the GraphDataDefault style element in the current style. For grouped data, the default color is specified by the ContrastColor attribute of the GraphData1 ... GraphDatan style elements in the current style.
PATTERN= line-pattern
specifies the line pattern for the line. You can reference SAS patterns by number or by name. For a list of line patterns, see Line Patterns.
Default:For ungrouped data, the default line pattern is specified by the LineStyle attribute of the GraphDataDefault style element in the current style. For grouped data, the default line pattern is specified by the LineStyle attribute of the GraphData1 ... GraphDatan style elements in the current style.
THICKNESS= n <units>
specifies the thickness of the line. You can also specify the unit of measure. The default unit is pixels. For a list of measurement units that are supported, see Units of Measurement.
Default:For ungrouped data, the default line thickness is specified by the LineThickness attribute of the GraphDataDefault style element in the current style. For grouped data, the default line thickness is specified by the LineThickness attribute of the GraphData1 ... GraphDatan style elements in the current style.
Here is an example expression:
LINEATTRS=(Color= "light green" Pattern= MediumDash Thickness= 4)
Default:For ungrouped data, line attributes are derived from the GraphDataDefault style element. For grouped data, the ContrastColor attribute of the GraphData1... GraphDatan style elements are used.
Interactions:This option takes effect only if the CONNECT= option is also specified.

This option is ignored if the GROUP= option is also specified.

MEANATTRS= style-element <(options)> | (options)
specifies the appearance of the marker that represents the mean in the box. You can specify the appearance by using a style element or by using suboptions. If you specify a style element, you can also specify suboptions to override specific appearance attributes.
options can be one or more of the following:
COLOR= color
specifies the color of the markers. You can specify colors using the same color schemes that are supported by SAS/GRAPH software. For more information, see Color-Naming Schemes in SAS/GRAPH: Reference.
Default:For ungrouped data, the default color is specified by the ContrastColor attribute of the GraphBoxMean style element in the current style. For grouped data, the default color is specified by the ContrastColor attribute of the GraphData1 ... GraphDatan style elements in the current style.
SIZE= n <units>
specifies the size of the markers. You can also specify the unit of measurement. The default unit is pixels. For a list of measurement units that are supported, see Units of Measurement.
Default:The default marker size is specified by the MarkerSize attribute of the GraphBoxMean style element in the current style.
SYMBOL= symbol-name
specifies the symbol for the markers. For a list of valid marker symbols, see Marker Symbols.
Default:For ungrouped data, the default marker symbol is specified by the MarkerSymbol attribute of the GraphBoxMean style element in the current style. For grouped data, the default marker symbol is specified by the MarkerSymbol attribute of the GraphData1 ... GraphDatan style elements in the current style.
WEIGHT= NORMAL | BOLD
specifies the marker weight of the marker.
Default:NORMAL
Default:GraphBoxMean is the default style element.
MEDIANATTRS= style-element <(options)> | (options)
specifies the appearance of the line that represents the median. You can specify the appearance by using a style element or by using suboptions. If you specify a style element, you can also specify suboptions to override specific appearance attributes.
options can be one or more of the following:
COLOR= color
specifies the color of the line. You can specify colors using the same color schemes that are supported by SAS/GRAPH software. For more information, see Color-Naming Schemes in SAS/GRAPH: Reference.
Default:For ungrouped data, the default color is specified by the ContrastColor attribute of the GraphBoxMedian style element in the current style. For grouped data, the default color is specified by the ContrastColor attribute of the GraphData1 ... GraphDatan style elements in the current style.
PATTERN= line-pattern
specifies the line pattern for the line. You can reference SAS patterns by number or by name. For a list of line patterns, see Line Patterns.
Default:For ungrouped data, the default line pattern is specified by the LineStyle attribute of the GraphBoxMedian style element in the current style. For grouped data, the default line pattern is specified by the LineStyle attribute of the GraphData1 ... GraphDatan style elements in the current style.
THICKNESS= n <units>
specifies the thickness of the line. You can also specify the unit of measure. The default unit is pixels. For a list of measurement units that are supported, see Units of Measurement.
Default:For ungrouped data, the default line thickness is specified by the LineThickness attribute of the GraphBoxMedian style element in the current style. For grouped data, the default line thickness is specified by the LineThickness attribute of the GraphData1 ... GraphDatan style elements in the current style.
Default: GraphBoxMedian is the default style element.
Interaction:This option is ignored if the NOMEDIAN option is also specified.
MISSING
processes missing values as a valid category value and creates a box for it.
NAME= “text-string
specifies a name for the plot. You can use the name to refer to this plot in other statements.
Note:The name is case-sensitive. When you refer to the specified name in other statements, you must use the same exact capitalization.
NOCAPS
hides the cap lines for the whiskers.
NOMEAN
hides the mean marker.
NOMEDIAN
hides the median line.
NOOUTLIERS
hides the outliers from the plot.
NOTCHES
specifies that the boxes be notched. The endpoints of the notches are at the following computed locations:
For a visual description of the parts of a box plot, see Details.
OUTLIERATTRS= style-element <(options)> | (options)
specifies the appearance of the marker that represents the outliers. You can specify the appearance by using a style element or by using suboptions. If you specify a style element, you can also specify suboptions to override specific appearance attributes.
options can be one or more of the following:
COLOR= color
specifies the color of the markers. You can specify colors using the same color schemes that are supported by SAS/GRAPH software. For more information, see Color-Naming Schemes in SAS/GRAPH: Reference.
Default:For ungrouped data, the default color is specified by the ContrastColor attribute of the GraphOutlier style element in the current style. For grouped data, the default color is specified by the ContrastColor attribute of the GraphData1 ... GraphDatan style elements in the current style.
SIZE= n <units>
specifies the size of the markers. You can also specify the unit of measurement. The default unit is pixels. For a list of measurement units that are supported, see Units of Measurement.
Default:The default marker size is specified by the MarkerSize attribute of the GraphOutlier style element in the current style.
SYMBOL= symbol-name
specifies the symbol for the markers. For a list of valid marker symbols, see Marker Symbols.
Default:For ungrouped data, the default marker symbol is specified by the MarkerSymbol attribute of the GraphOutlier style element in the current style. For grouped data, the default marker symbol is specified by the MarkerSymbol attribute of the GraphData1 ... GraphDatan style elements in the current style.
WEIGHT= NORMAL | BOLD
specifies the marker weight of the marker.
Default:NORMAL
Default:GraphOutlier is the default style element.
PERCENTILE= 1 | 2 | 3 | 4 | 5
specifies a method for computing the percentiles for the plot. For descriptions of each method, see “Calculating Percentiles” in the UNIVARIATE Procedure chapter of Base SAS Procedures Guide: Statistical Procedures.
Default:5
SPREAD
relocates outlier points that have identical values to prevent overlapping.
Note:This option has no effect if your data does not contain two or more outliers with identical values for the analysis variable.
TRANSPARENCY= value
specifies the degree of transparency for the plot. Specify a value from 0.0 (completely opaque) to 1.0 (completely transparent).
Default:0.0
WHISKERATTRS= style-element <(options)> | (options)
specifies the appearance of the whisker and cap lines. You can specify the appearance by using a style element or by using suboptions. If you specify a style element, you can also specify suboptions to override specific appearance attributes.
options can be one or more of the following:
COLOR= color
specifies the color of the line. You can specify colors using the same color schemes that are supported by SAS/GRAPH software. For more information, see Color-Naming Schemes in SAS/GRAPH: Reference.
Default:For ungrouped data, the default color is specified by the ContrastColor attribute of the GraphBoxWhisker style element in the current style. For grouped data, the default color is specified by the ContrastColor attribute of the GraphData1 ... GraphDatan style elements in the current style.
PATTERN= line-pattern
specifies the line pattern for the line. You can reference SAS patterns by number or by name. For a list of line patterns, see Line Patterns.
Default:For ungrouped data, the default line pattern is specified by the LineStyle attribute of the GraphBoxWhisker style element in the current style. For grouped data, the default line pattern is specified by the LineStyle attribute of the GraphData1 ... GraphDatan style elements in the current style.
THICKNESS= n <units>
specifies the thickness of the line. You can also specify the unit of measure. The default unit is pixels. For a list of measurement units that are supported, see Units of Measurement.
Default:For ungrouped data, the default line thickness is specified by the LineThickness attribute of the GraphBoxWhisker style element in the current style. For grouped data, the default line thickness is specified by the LineThickness attribute of the GraphData1 ... GraphDatan style elements in the current style.
Default:GraphBoxWhisker is the default style element.
Interaction:This option is ignored if the NOMEDIAN option is also specified.
X2AXIS
assigns the category variable to the secondary (top) horizontal axis.
Y2AXIS
assigns the response variable to the secondary (right) vertical axis.

Details

Horizontal and vertical box plots display the distribution of data by using a rectangular box and whiskers. Whiskers are lines that indicate a data range outside of the box.
Parts of a Box Plot
Parts of a Box Plot
Parts of a Box Plot shows a diagram of a vertical box plot. The bottom and top edges of the box indicate the intra-quartile range (IQR). That is, the range of values between the first and third quartiles (the 25th and 75th percentiles). The marker inside the box indicates the mean value. The line inside the box indicates the median value.
The elements that are outside the box are dependent on your options. By default, the whiskers that extend from each box indicate the range of values that are outside of the intra-quartile range. However, the values are close enough not to be considered outliers (a distance less than or equal to 1.5*IQR). If you specify the EXTREME option, then the whiskers indicate the entire range of values, including outliers.
Any points that are a distance of more than 1.5*IQR from the box are considered to be outliers. By default, these points are indicated by markers. If you specify DATALABEL= option, then the outlier points have data labels. If you also specify the LABELFAR option, then only outliers that are 3*IQR from the box have data labels.