Date/Time Values

NetCharts supports the use of Date/Time values for one or more values in a data set value.
The following parameters are used to define the attributes needed for Date/Time processing:

TopFormat    = (DATE, "DateFormat", "TimeBase", "TimeUnit");
BottomFormat = (DATE, "DateFormat", "TimeBase", "TimeUnit");
LeftFormat   = (DATE, "DateFormat", "TimeBase", "TimeUnit");
RightFormat  = (DATE, "DateFormat", "TimeBase", "TimeUnit");

TopScale     = (MinValue, MaxValue, StepValue);
BottomScale  = (MinValue, MaxValue, StepValue);
LeftScale    = (MinValue, MaxValue, StepValue);
RightScale   = (MinValue, MaxValue, StepValue);
TopScroll    = (ScrollMin, ScrollMax);
BottomScroll = (ScrollMin, ScrollMax);
LeftScroll   = (ScrollMin, ScrollMax);
RightScroll  = (ScrollMin, ScrollMax);
DataSet[1-20]
LineSet[1-20]

Date/Time value processing is enabled by setting a given axis type to DATE. The date values associated with that axis will then be processed as date/time values. Specifically, that means any data value associated with that axis can be input in any of the following formats:

• Absolute Date Expression
• Relative Time Unit
• Numeric Time Unit
• SimpleDate Formats

Regardless of how the date/time value is entered as a data value, the display of the value, either as a tic mark label or an active label, will be rendered using the FormatExpr attribute specified in the TopFormat, BottomFormat, LeftFormat or RightFormat parameters. See Axis Parameters for more details concerning date label formatting.

Absolute Date Expression

An Absolute Date Expression is any quoted string that represents a date and/or time in some standard convention. Java automatically recognizes many date/time formats, including the following:

Absolute Date Expressions are best used for specifying the min or max values in an axis range, or when specifying an exact time-based data value. The following expressions are valid Absolute Date Expressions:

1 Jan 2000 12:30
Jan 1, 2000
12:30
Wed, 10 Apr 00

This example shows an XY chart with the X values specified as absolute date expressions.

BottomFormat = (DATE, "%M/%D");
BottomScale  = ("10 Apr 00", "17 Apr 96");
DataSet1     = ("10 Apr 00",       27),
               ("12 Apr 00 05:30", 50),
               ("4/13/2000",       75),
               ("4/14/00 12:30",   37),
               ("April 15, 00",    87),
               ("Apr 16, 00 12:00",64);

Relative Time Unit

You may want to specify a date/time value that is relative to another. For example, a measurement might be taken 20 minutes after the start of an experiment, or a task might end 5 days and 6 hours after the start of the task. In such cases, a Relative Time Unit can be entered, using the following syntax:

	Relative Time Unit = "1Y 2M 3d 12h 30m";

	"7d"

	"3d 12h 30m"

The absolute date/time represented by a given relative time unit is determined as follows:

       Absolute DateTime = Axis TimeBase + Relative Time Unit

where TimeBase is defined in the Format parameter for the corresponding axis.

For example, the following parameters specify the same axis and data values as above, except that they use Relative Time Unit values:

BottomFormat = (DATE, "%M/%D", "10 Apr 00");
BottomScale  = ("0d", "7d");
DataSet1     = ("0d",         27),
               ("2d 5h 30m",  50),
               ("3d",         75),
               ("4d 12h 30m", 37),
               ("120h",       87),
               ("6d 12h",     64);

Note, the TimeBase attribute of the BottomFormat parameter is used to "anchor" the graph on a given starting date, all other date/times are relative to that base date.

Also, note how the April 15 value is specified as 120 hours (5 days) past the base date.

Numeric Time Unit

Date/time values may also be specified as a numeric value, which is interpreted as follows:

Absolute DateTime = Axis TimeBase + N * Axis TimeUnit

For example, the following parameters generate the same chart as displayed above, except that they use a combination of absolute dates, relative time units and numeric time units.

BottomFormat = (DATE, "%M/%D", "10 Apr 00", "1d");
BottomScale  = (0, "Apr 17, 2000");
TopFormat    = (DATE, "%w", "10 Apr 00", "1d");
TopScale     = (0, "Apr 17, 2000");
DataSet1     = ("10 Apr 00",  27),
               ("2d 5h 30m",  50),
               (3.0,          75),
               ("4d 12h 30m", 37),
               (5,            87),
               (6.5,          64);

Note
The TopFormat is used to display the day of the week.