valueErrorBar

Configures error bars.

Type: Object

Error bars are used on charts to indicate an error or an uncertainty in a reported measurement. They give a general idea of how precise a measurement is.

In dxPolarChart, an error bar is a vertical bar with two marks at its edges. An error bar accompanies a series point. Error bars can be generated either from concrete or calculated values. To generate one error bar, two values, high and low, are needed. If the data source of your chart provides concrete high and low values, assign the required data source fields to the highValueField and lowValueField options.

Alternatively, you can calculate the high and low error bar values automatically. For this purpose, choose one of error bar types and specify the value to be used in calculation.

NOTE
Error bars are available for axes of a numeric type only.

color

Specifies the color of error bars.

Type: String
Default Value: black

This option supports the following colors.

  • Hexadecimal colors
  • RGB colors
  • RGBA colors (not supported in Internet Explorer 8)
  • Predefined/cross-browser color names
  • Predefined SVG colors (not supported in Internet Explorer 8)

displayMode

Specifies whether error bars must be displayed in full or partially.

Type: String
Default Value: 'auto'
Accepted Values: 'auto' | 'low' | 'high' | 'none'

Usually, when displaying error bars, you need both the lower and higher parts of them to indicate the error. This case corresponds to the displayMode option equaling 'auto'. If you need to display the lower or higher parts separately, set this option to 'low' or 'high' respectively. To hide error bars, assign 'none' to this option.

edgeLength

Specifies the length of the lines that indicate the error bar edges.

Type: Number
Default Value: 8

highValueField

Specifies the data field that provides data for high error values.

Type: String
Default Value: undefined

If you need to generate error bars from concrete values, specify the highValueField option with the name of the field that provides them. These values will be displayed on a chart as the higher end of error bars. To provide data for the lower end of error bars, specify the lowValueField option.

NOTE
If you generate error bars from concrete values, do not specify the valueErrorBar | type option.

lineWidth

Specifies the width of the error bar line.

Type: Number
Default Value: 2

lowValueField

Specifies the data field that provides data for low error values.

Type: String
Default Value: undefined

If you need to generate error bars from concrete values, specify the lowValueField option with the name of the field that provides them. These values will be displayed on a chart as the lower end of error bars. To provide data for the higher end of error bars, specify the highValueField option.

NOTE
If you generate error bars from concrete values, do not specify the valueErrorBar | type option.

opacity

Specifies the opacity of error bars.

Type: Number
Default Value: undefined

type

Specifies how error bar values must be calculated.

Type: String
Default Value: undefined
Accepted Values: 'percent' | 'stdError' | 'stdDeviation' | 'variance' | 'fixed'

Depending on the type of errors you need to visualize, use the error bars of one of the following types.

  • percent
    Defines the confidential interval in percentages. Error bar values are calculated as a percentage of the series point value. The percentage value is determined by the value option. The high and low error bar values are drawn symmetrically up and down from the series point.

  • stdError
    For information on the standard error, refer to the article in Wikipedia.

  • stdDeviation
    For information on the standard deviation, refer to the article in Wikipedia.

  • variance
    For information on variance, refer to the article in Wikipedia.

  • fixed
    Defines the confidential interval in constant values. Error bar values are determined by the value option. The high and low error bar values are drawn symmetrically up and down from the series point.

value

Specifies the value to be used for generating error bars.

Type: Number
Default Value: 1

Depending on the value of the type option, the value option is applied as follows.

  • type: 'percent'
    The value option specifies the percentage of the series point value to be taken.

  • type: 'stdError'
    The value option multiplies the calculated standard error.

  • type: 'stdDeviation'
    The value option multiplies the calculated standard deviation.

  • type: 'variance'
    The value option multiplies the calculated variance.

  • type: 'fixed'
    The value option specifies constant error bar values.