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

Function/S ArcTangentBP_BLFuncInfo(InfoDesired)
	Variable InfoDesired

	String info=""

	switch(InfoDesired)
		case BLFuncInfo_ParamNames:
			info = "y0;x0;deltaY;dilation;"
			break;
		case BLFuncInfo_BaselineFName:
			info = "arctan_BLFunc"
			break;
	endswitch

	return info
end

static Constant pio2 = 1.5707963267949

Function arctan_BLFunc(s)
	STRUCT MPF2_BLFitStruct &s
	
	Variable xx = (s.x-s.cwave[1])/s.cwave[3]
	Variable scale = s.cwave[2]/pi
	
	return s.cwave[0] + (pio2 + atan(xx))*scale
end