WxML interval attribute

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interval

The interval attribute specifies a fixed interval between successive values in a range. It should be in the form of an integer or floating-point number. Example of its use include specifying the interval between successive lines in a contour plot or the spacing of range rings. The interval attribute is also used to specify a fixed time interval in seconds between the frames of an animated map.

Supporting Tags

The interval attribute is supported by the <range> tag. The default value of the interval attribute depends upon the context in which it is used. The parent of the <range> tag usually picks an appropriate default when the interval is omitted.

The interval attribute is also supported by the <pulse> tag. The default value of the interval attribute in a pulse tag is 60 seconds.

Examples

<contour> <data src="latest.mdf" param="TAIR" units="cels"/> <range low="0.0" high="100.0" interval="2.0"/> </contour> <contour> <data src="latest.mdf" param="RAIN" units="mm"/> <range interval="0.1"/> </contour> <rangeRings> <centerSite network="Oklahoma Mesonet" site="NORM" units="km"/> <range low="20" high="200" interval="20"/> </rangeRings> <map> <pulse interval="900" rate="30"/> </map>

Notes

Because the high attribute should always be greater than the low attribute, the interval value should always be greater than zero.

Note that it is possible to specify an interval while omitting the low and high values. This allows you to fix the spacing between successive values while letting the limits float with the relevant data set.

The syncTo attribute may used in place of the interval attribute in the <pulse> tag when the frames of a data set don't have a fixed time interval between them. Use of the interval attribute in the <pulse> tag works best with data sets such as Mesonet data, which have a fixed time interval between all of the frames.