BarLegend

BarLegend[cf]

generates a legend that identifies colors from the color function cf with an automatic range of values.

BarLegend[{cf,{min,max}}]

generates a legend that identifies colors from the color function cf with the range of values between min and max.

BarLegend[cf,contours]

generates a legend that identifies color ranges from the color function cf based on the set of contours contours.

Details and Options

  • BarLegend uses a list of colors associated with color function cf to identify the contours between min and max in the visualization or other legended item.
  • BarLegend is used automatically in functions such as ContourPlot and ListContourPlot.
  • Within visualization functions, Automatic in BarLegend[Automatic,] is automatically replaced by the actual color function, data range, and contours specification needed to determine the contour values and colors in between.
  • In BarLegend, contours can take the following forms:
  • ncontours at n equally spaced levels
    Automaticcontours chosen automatically
    Allall contours
    Noneno contours
    {Automatic,n}at most n contours chosen automatically
    {f1,f2,}contours at levels fi
    {{f1,gr1},}contours drawn with graphics directives gri
    funca function to be applied to zmin, zmax to get the list of contours
  • BarLegend[cf,contours] may use a list of colors or a continuous spectrum depending on the density of contour values.
  • Legended[expr,BarLegend[]] can be used to apply a legend to an arbitrary expression expr.
  • The following options can be given:
  • LabelStyleAutomaticstyle to use for labels
    LegendFunctionIdentitywrapper for the overall legend
    LegendLabelNoneoverall label for legend
    LegendLayoutAutomaticlegend layout to use
    LegendMarginsAutomaticspace between legend content and boundaries
    LegendMarkersNonemarkers to use to indicate each element
    LegendMarkerSizeAutomaticsize of the shape
  • BarLegend is displayed in StandardForm as a graphics object. In InputForm, it is displayed as an explicit list of color function, data range, and contour values.
  • In BarLegend, LegendLayout can have the following forms:
  • Automaticautomatically determine layout
    "Row"display legend in a horizontal row
    "Column"display legend in a vertical column
  • In LineLegend, LegendLayout can have the following forms:
  • Automaticautomatically determine layout
    "Row"display legend in a horizontal row
    "Column"display legend in a vertical column
    "ReversedRow"display reversed legend in a horizontal row
    "ReversedColumn"display reversed legend in a vertical column
  • LegendFunction is applied to the legend, including any overall label and margins.

Examples

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Basic Examples  (7)

A continuous gradient bar:

Specify the data range:

Use five equally spaced contours:

Use color schemes:

Use Hue:

Use GrayLevel:

Generate automatic legends for a plot:

Scope  (22)

Color Function  (4)

Use named color schemes:

Specify a range for the color function:

Use a list of colors and a matching number of contours:

Color lists are blended to match contours:

Use a function:

Contours  (10)

Automatic select contours:

Select five equally spaced contours:

Specify an explicit set of contours:

Select at most 10 contours automatically:

BarLegend uses a continuous gradient when contour lines are dense:

Specify the data range:

Use a function to determine contours:

BarLegend selectively labels contours:

Use All to label all the contours:

Use None to draw a continuous gradient:

Plot Legends  (8)

Density and contour plots use BarLegend:

Change the legend position with Placed:

BarLegend automatically changes position and size depending on the aspect ratio:

BarLegend automatically picks up values of ColorFunction and ColorFunctionScaling:

BarLegend automatically picks up contour values:

BarLegend includes specified contour styles:

BarLegend matches shaded styles between contours:

Use BarLegend to specify a label and frame for the automatically computed legend:

Options  (20)

LabelStyle  (3)

All labels have the same default style:

Specify styles to labels:

LabelStyle applies to LegendLabel:

LegendFunction  (5)

Use frame:

Use a panel:

Use an arbitrary function:

Use a styled frame:

Use a shadow box:

LegendLayout  (1)

Draw the legend as a row or column:

LegendLabel  (6)

Give a legend label:

Legend label is inside the legend container:

Use Placed to position the legend label inside the frame:

Use Placed to position the legend label outside the frame:

Use the third argument in Placed to rotate the legend label:

LegendMargins  (3)

No margins between content and boundaries:

Specify the same margin to all boundaries:

Specify different margins to boundaries:

LegendMarkerSize  (2)

Automatic size:

Specify LegendMarkerSize:

Introduced in 2012
 (9.0)