Compute Market Open and Close Times for Axis Breaks

DESCRIPTION:

An internal function used by time series graphics to compute where to put axis breaks when plotting time series.

USAGE:

axis.compute.time.breaks(pos, min.span=NULL, mkt.oc=TRUE,  
                         align=TRUE, by.align=NULL, k.by.align=NULL) 

REQUIRED ARGUMENTS:

pos
the positions (x-values) of the series.

OPTIONAL ARGUMENTS:

min.span
a time span object that is used to identify breaks as those time periods without positions that exceed min.span. If NULL, the default is selected from axis.break.table based on min(diff(pos))
mkt.oc
TRUE or FALSE to determine whether daily market opening and closing times to use as axis breaks should be estimated from pos; can also be a list (or data frame) with open and close components (columns) giving the regular opening and closing times of the market to use for generating axis breaks. The times are given as time span objects, representing the time after midnight for the daily openings and closings of the market.
align
if TRUE, the break intervals are extended so that the intervals are aligned according to by.align and k.by.align.
by.align
a character string giving the time units for aligning the intervals if align is TRUE. Possible values are "years", "quarters", "months", "weeks", "days", "hours", "minutes", "minutes", "seconds", or "milliseconds". If NULL, the default is selected from axis.break.table based on min(diff(pos))
k.by.align
an integer indicating the number of by.align units for aligning. If NULL, the default is selected from axis.break.table based on min(diff(pos))

VALUE:

a list with open and close components, giving the market open and close times to use in axis breaks.

DETAILS:

This function is intended for internal use by the time series graphics functions and is called by axis.time.build.

SEE ALSO:

axis.time.build, axis.break.table.