chron prefab


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Manual page for chron_prefab(PL)

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EXAMPLE 1 - Dates

pl  -prefab chron  data=data14  x=1  y=2  datefmt=yy/mm/dd  xinc="1 month" \
     stubfmt=M  xyears=yyyy  yrange="0 25"  barwidth=line  color=red  \
     title="# hits per day"  omitweekends=yes


The data14 file:
	00/12/21 1
	00/12/22 1
	00/12/23 2
	00/12/27 1
        ...etc.


EXAMPLE 2 - Dates - tabulated by week


pl  -prefab chron  data=data14  x=1  y=2  datefmt=yy/mm/dd  xinc="1 month" \
      stubfmt=M  xyears=yyyy  color=green  tab=week  title="# hits per week"

EXAMPLE 3 - Dates - tabulated by week



pl  -prefab chron  data=data14  x=1  y=2  datefmt=yy/mm/dd  xinc="14 days" \
     stubfmt=MMMdd  stubvert=yes  tab=week  tabmode=first  mode=line  ygrid=yes \
     step=yes  linedet="color=redorange width=2"  xrange="01/04/08 01/09/01"  \
     yrange="0 40"  title="# hits per week"

EXAMPLE 4 - Dates - tabulated by month



pl  -prefab chron  data=data14  x=1  y=2  datefmt=yy/mm/dd  xinc="1 month"  \
	stubfmt=M  xyears=yyyy  color=powderblue  tab=month  tabmode=first  \
	nearest=month  barwidth=0.2  curve=yes 


EXAMPLE 5 - Datetimes - tabulated by hour


pl -prefab chron  data=data16  x=1  tab=hour  datefmt=yy/mm/dd  xinc="1 day" \
	barwidth=line  stubfmt=MMMdd  unittype=datetime  timefld=2  \
	title="# hits per hour"


The data16 file:
	01/09/05	09:43:35
	01/09/05	09:43:40
	01/09/05	13:15:00
	01/09/05	13:15:11
	...etc.

Note that a file such as this (data13) could also be used, and timefld
would not need to specified:
	01/09/05.09:43:35
	01/09/05.09:43:40
	01/09/05.13:15:00
	01/09/05.13:15:11
	..etc.

EXAMPLE 6 - Times - tabulated by hour

pl -prefab chron  data=data15  x=1  tab=hour unittype=time xinc="1 hour" \
	nearest=hour  barwidth=0.2  stubfmt=HHA  \
	title="# events per hour"  color=coral


The data15 file:
	07:47:49
	07:47:52
	07:47:54
	..etc.

How to run these examples

DESCRIPTION

chron is a prefab for plotting chronological data. Data may be expressed as dates , times (seconds portion is optional) , or a combination of date and time called datetime . chron can produce bar or line plots, and can plot explicit values or tabulate by week, month, day, hour, etc. Time is shown along the X axis. The data file must be in chronological order.




PARAMETERS

standard prefab parameters are all supported except err. data and x are always required. Data field x must contain dates, times, or datetimes. Data field y may contain values. xinc supports constructs such as "1 month"; if only a number is given, it is assumed to be days (the default for xinc is 7 days).

unittype specifies the type of chronological scaling. Default is date. Allowable values are time, datetime and datetime .

mode is either bars (the default) or line.

datefmt is the date format you are using. This must be specified unless using the default format (as set in a config file , otherwise mmddyy). If plotting datetime values, datefmt specifies only the date portion. If plotting time values, datefmt is ignored.

stubfmt is the date format or time format to be used for X axis stubs. The defaults are MMMdd (date) and HHa (time). You can use stubvert=yes to render stubs vertically.

xyears allows years to be displayed along X axis below date X stubs. Use yy for 2 digit year eg 01, yyy for eg '01, and yyyy for eg 2001.

omitweekends may be specified as yes to allow the graph to be drawn such that Friday is followed immediately by Monday. Any data points falling on a Saturday or Sunday are silently adjusted to the nearest weekday.

tab tabulates data by hour, day, week, month, quarter-year, or year. If a y data field is being used, the y values will be totaled; otherwise, instances will be counted. Tabulation is done by internally adjusting dates and then counting.

tabmode is used with tab. Allowable values are mid and first (default is mid). mid causes tabulations to be based on a date or time in the middle of the interval; for first the beginning of the interval is used. mid is appropriate for some types of plots while first is better for others.

timefld specifies a data field that holds time values. Normally when plotting datetimes , dates and times are combined into one data field, separated by a period (.). If timefld is used, however, dates may be in one data field (x) and times in another.

nearest may be used to specify cutoffs for automatic scaling in X. For example, nearest=month would cause X min and max to fall on month boundaries. Allowable values are hour, day, month, quarter, and year.

curve may be specified as yes or as a linedetails value , and causes a moving average curve to be fit and drawn. order (default = 5) may be used to control the number of points considered when computing the moving average curve (higher value = smoother curve).

If mode is bars:

barwidth controls the width of bars This is a value in inches, or may be given as line for very thin bars.

color controls the color of bars, if mode=bars.

crossover may be specified as the value in Y where bars begin to point downward instead of upward. For instance, crossover=0 is often useful when dealing with financial income, to show loss using downward bars.

If mode is line:

linedet controls the appearance of the line, if mode=line.

step may be given as yes to get a stairstep line.

Note: Because filter processing is applied to data as they are read, tabulate cannot be set from within the data file. If tabulate is used, x, y and datefmt cannot be set from within the data file.


data display engine  
Copyright Steve Grubb


Markup created by unroff 1.0,    September 17, 2001.