PROGRAM LABCOORD
C==========================================================================
C
C	Programmer: Andrew Dainis		5-DEC-88
C
C This program will calculate the X,Y coordinates of four points given the
C the six distances between the points which are assumed to lie in a plane.
C Point 1 is made the coordinate system origin, and point 2 is placed on the 
C Y-axis. The measurements S12, S13, S14, S23, S24, S34 are assumed to be 
C entered in that order and the first five are used to compute the point
C coordinates. The sixth distance is computed from the first five, and 
C should agree with the measured distance between points 3 and 4.
C Points are order clockwise.
C===========================================================================
C
	WRITE(*,*) ' POINTS ARE ORDERED CLOCKWISE'
	WRITE(*,*) ' '
	WRITE(5,200) 
  200	FORMAT(' Enter the distance between points 1 and 2 :',$)
	READ(*,*) S12
	WRITE(5,203) 
  203	FORMAT(' Enter the distance between points 2 and 3 :',$)
	READ(*,*) S23
	WRITE(5,205) 
  205	FORMAT(' Enter the distance between points 3 and 4 :',$)
	READ(*,*) S34
	WRITE(5,202) 
  202	FORMAT(' Enter the distance between points 4 and 1 :',$)
	READ(*,*) S14
	WRITE(5,201) 
  201	FORMAT(' Enter the distance between points 1 and 3 :',$)
	READ(*,*) S13
	WRITE(5,204) 
  204	FORMAT(' Enter the distance between points 2 and 4 :',$)
	READ(*,*) S24
C
	PI=3.14159
	A=(S12**2+S14**2-S24**2)/(2.*S12*S14)
	W=ACOS(A)
	IF(A.LT.0) W=PI-W			! > 90 degrees
	W=PI/2.-W
	X4=S14*COS(W)
	Y4=S14*SIN(W)
	IF(A.LT.0) Y4=-Y4
C
	A=(S12**2+S23**2-S13**2)/(2.*S12*S23)
	W=ACOS(A)
	IF(A.LT.0) W=PI-W
	W=W-PI/2.
	X3=S23*COS(W)
	Y3=S12+S23*SIN(W)
	IF(A.LT.0) Y3=S12-S23*SIN(W)
C
	CS34=SQRT((X4-X3)**2+(Y4-Y3)**2)
C
	WRITE(*,*) ' '
	WRITE(5,100) 0.0,0.0
  100	FORMAT(' Point 1 is located at ',2F10.4)
	WRITE(5,101) 0.0,S12
  101	FORMAT(' Point 2 is located at ',2F10.4)
	WRITE(5,102) X3,Y3
  102	FORMAT(' Point 3 is located at ',2F10.4)
	WRITE(5,103) X4,Y4
  103	FORMAT(' Point 4 is located at ',2F10.4)
	WRITE(*,*) ' '
	WRITE(5,104) CS34-S34
  104	FORMAT(' Calculated distance points 3 to 4 is longer than the',
     * 	/' measured distance by ',F8.4)

	END