'----------------------------------------------------------------
'SCRIPT:    avu-Line2Azimuth
'PROJECT:   gavos.apr, avcsus 
'DATE:      03-18-96
'AUTHOR:    John Ganter, Sandia National Labs, jganter@sandia.gov
'DESC:      converts xy,xy to an azimuth angle
'DESC2:     azimuths (0 or 360=North, 180=South, etc.) let you do
'           easy trigonometry in any Cartesian quadrant (I to IV).
'CALLED BY: 
'CALL AS:   av.Run("avu-Line2Azimuth", <List>)
'ARG01:     List: {Ax, Ay, Bx, By}
'RETURNS:   number
'EXPECTS:   <nothing>
'CALLS TO:  <nothing>
''''2----------------------------------------------------------------

'get the coordinates

AAx = SELF.Get(0)
AAy = SELF.Get(1)
BBx = SELF.Get(2) 
BBy = SELF.Get(3)

'calc the hypoteneuse
  
  numH = ( ((BBx - AAx)^2) + ((BBy - AAy)^2) ).Sqrt
  
'calc angle
  
  numOp = (AAx - BBx).Abs
  angrThe = (numOp / numH).ASin 
 
If ( (BBx >= AAx) AND (BBy >= AAy) ) then
  quad = "NE"  
  angdThe = angrThe.AsDegrees
  
elseif ( (BBx >= AAx) AND (BBy <= AAy) ) then
  quad = "SE" 
  angdThe = 180 - angrThe.AsDegrees

elseif ( (BBx <= AAx) AND (BBy <= AAy) ) then
  quad = "SW" 
  angdThe = 180 + angrThe.AsDegrees
  
elseif ( (BBx <= AAx) AND (BBy >= AAy) ) then
  quad = "NW"
  angdThe = 360 - angrThe.AsDegrees 

else
  MsgBox.Error("The arguments are invalid","")

end

'MsgBox.Info(quad ++ numH.AsString ++ numOp.AsString ++ angdThe.AsString,"")

Return angdThe

'----end of script---------------------------------------------------