


C
C	PROGRAM THIDE.FOR
C
C	THIS PROGRAM DEMONSTRATES THE USE OF THE HIDDEN LINE
C	REMOVAL PLOT SUBROUTINE, 'HIDE', TO PLOT BOTH SIDES
C	OF A FUNCTIONAL SURFACE.
C
C	M.W. VANNIER
C	WENNER GREN LAB
C	UNIV OF KENTUCKY
C	27 AUGUST 1976
C
	INTEGER*2 T(3)
	DIMENSION X(150),Y(150),Y1(150)
	DIMENSION XG(500),G(500),XG1(500),G1(500),XH(500),H(500)
	COMMON X,Y,Y1,XG,G,XG1,G1,XH,H
	DATA T /2HNO,2HTT,2HLE/
C
C	DEFINE PLOTTING VARIABLES
C
	NG     =-1
	NG1    =-3
	N      = 150
	N1     =-N
	NFNS   = 26
	MAXDIM = 500
	XM     = 0.0
	DX     = 1.05
	DY     = 0.67
	YM     =-1.0
	XLNTH  =-6.0
	YLNTH  =-3.0
	PI     = 3.14159
C
C
	TYPE 11
11	FORMAT (//,15X,'THIDE - HIDDEN SURFACE PLOT PROGRAM',//)
C
C
	DO 1 I=1,N
	X(I)  = FLOAT(I-1)*PI/74.5
1	Y1(I) = 0.2*SIN(X(I))
C
C	LOOP FOR EACH CURVE TO BE PLOTTED, COMPUTING THE
C	ORDINATE COEFFICIENTS EACH TIME
C
	CALL PLOTS
	CALL PLOT (1.0,2.0,-3)
	CALL FACTOR (0.8)
	DO 3 I=1,NFNS
	Z = FLOAT(I-1)*PI/12.5
	CZ = COS(Z)
	DO 2 J=1,N
2	Y(J) = Y1(J)*CZ-(EXP(-(X(J)-PI)**2-(Z-PI)**2)*
	1       COS(1.75*((X(J)-PI)**2+(Z-PI)**2)))*1.5
C
C	PLOT TOP OF SURFACE
C
	CALL HIDE (X,Y,XG,G,XH,H,NG,MAXDIM,N,NFNS,T,
	1           XLNTH,YLNTH,XM,DX,YM,DY)
C
C	PLOT BOTTOM OF SURFACE
C
3	CALL HIDE (X,Y,XG1,G1,XH,H,NG1,MAXDIM,N1,0,T,
	1           XLNTH,YLNTH,XM,DX,YM,DY)
C
C
	TYPE 4,NG,NG1
4	FORMAT (/,' NG =',I4,20X,'  NG1 =',I4,//)
	CALL PLOT (0,0,999)
	STOP 'NORMAL TERMINATION'
	END

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