#pragma rtGlobals=3		// Use modern global access method and strict wave access.

Function CatWind(windwave)
	Wave windwave
	Make/FREE binlist = {165,180,210,220,255,300}	// the list of bins, i.e., 0 to 165,  165 to 180 etc. ... data above the last item will be stored in 'the rest'

	// +++ first step: sort the waves after wind direction +++
	String Datalist = wavelist("!"+nameofwave(windwave),";","")+nameofwave(windwave)	// make a list of all waves, make sure the wind data comes last!
	Variable i, pointnum
	String currentname
	for (i = 0; i < itemsinlist(Datalist); i +=1)	// for every data wave sort after wind direction (including wind direction itself)
		currentname = Stringfromlist(i,Datalist)	// extract the name of the current wave from the list
		Wave current = $currentname	// create a wave reference to work with
		Sort windwave, current	// sort
	endfor
	// +++ second step: get rid of points with no valid wind data (i.e., nans) +++
	FindValue /V=(Wavemax(windwave)) windwave	// find the last point with valid data
	pointnum = V_Value
	for (i = 0; i < itemsinlist(Datalist); i +=1)
		currentname = Stringfromlist(i,Datalist)
		Wave current = $currentname
		DeletePoints pointnum+1, inf, current	// delete points after valid data
	endfor
	// +++ third step: store the data in separate folders depending on binning criteria +++	
	Variable currbin
	for (currbin = 0; currbin < numpnts(binlist); currbin +=1)
		FindLevel/Q windwave, binlist[currbin]	// find the crossing point to the next bin in the data
		pointnum = ceil(V_LevelX)
		NewDataFolder/O $("binned_"+num2istr(binlist[currbin]))	// create a data folder
		DFREF folder =root:$("binned_"+num2istr(binlist[currbin]))	// refer the data folder to work with
		for (i = 0; i < itemsinlist(Datalist); i +=1)
			currentname = Stringfromlist(i,Datalist)
			Duplicate/O $currentname, folder:$(currentname)	// duplicate into data folder
			Wave current = $(currentname)
			Wave copy = folder:$(currentname)
			DeletePoints 0, pointnum, current	// delete points of current bin in main waves
			DeletePoints pointnum, inf, copy	// delete points OUTSIDE current bin in copied wave
		endfor
	endfor
	
	NewDataFolder/O $("binned_rest")	// the data above the last bin will be stored in 'rest'
	DFREF folder =root:$("binned_rest")
	for (i = 0; i < itemsinlist(Datalist); i +=1)
		currentname = Stringfromlist(i,Datalist)
		Duplicate/O $currentname, folder:$(currentname)
		Wave current = $(currentname)
		KillWaves/Z current	// kill the main waves if possible (keeps stuff tidy)
	endfor
End