Bracket()

Finds the index position of a given value in an array.

BRACKET xarray=Realarray xval=Real Allows bracketing of X values.

example:

	# Rebin data to a smaller range manually
	>> lower = bracket(w.x, 1000.0)
	>> upper = bracket(w.x, 4000.0)
	>> w.x = w.x[(lower):(uppper)]
	>> w.y = w.y[(lower):(uppper-1)]
	>> w.e = w.e[(lower):(uppper-1)]

Note: Normally this would be done with the Rebin() command.

Bracket

This command is effectively used to "find" the location or neareset location to a number in a real array where the assumption (for all i x[i] <= x[i+1]) holds true for an array "x" (the X values of a histogram).

This command is used when it is necessary to bracket out a section of a histogram based on the actual X values.

Parameters:

Xarray (Realarray)

An array which fulfils the assumption above.

Xval (Real)

The value being searched for.

RESULT = (Integer)

This is either the index of the first element with the value "xval" or the index of the element such that "xval" would be included within the open interval (x[i], x[i+1]) where i is the returned index.

If the range where the value would be found is not present in the array then a value of -1 is returned.