Initial revision

difrac/pfind.f

@@ -0,0 +1,54 @@
+C-----------------------------------------------------------------------
+C  Get the coarse value of Phi for PCENTR
+C-----------------------------------------------------------------------
+      SUBROUTINE PFIND (TIM)
+      INCLUDE 'COMDIF'
+      DIMENSION PCOUNT(NSIZE)
+      EQUIVALENCE (ACOUNT(9*NSIZE + 1), PCOUNT(1))
+C-----------------------------------------------------------------------
+C  If offset by 2.5 deg and do 20 0.25 deg steps then we should find
+C  the maximum.
+C-----------------------------------------------------------------------
+      STEPM = 0.05
+      PSTEP = 0.25
+      NPTS = 20
+      NATT = 0
+C-----------------------------------------------------------------------
+C  Offset phi to the start of the scan
+C-----------------------------------------------------------------------
+  100 POFFS = PSTEP*10.0
+      PHI = PHI - POFFS
+      IF (PHI .LT.   0.0) PHI = PHI + 360.0
+      IF (PHI .GE. 360.0) PHI = PHI - 360.0
+      PHIOFF = PHI 
+      CALL ANGSET (THETA,OMEGA,CHI,PHI,NATT,ICOL)
+C-----------------------------------------------------------------------
+C  Find the max intensity either by step and count or by doing a scan,
+C  depending on the type of diffractometer
+C-----------------------------------------------------------------------
+      ICOUNT = 0
+      MCOUNT = 0
+      DO 110 I = 1,NPTS
+        CALL CTIME (TIM,PCOUNT(I))
+        IF (PCOUNT(I) .GT. MCOUNT) THEN
+          MCOUNT = PCOUNT(I)
+          ICOUNT = I
+        ENDIF
+        PHI = PHI + PSTEP
+        IF (PHI .LT.   0.0) PHI = PHI + 360.0
+        IF (PHI .GE. 360.0) PHI = PHI - 360.0
+        CALL ANGSET (THETA,OMEGA,CHI,PHI,NATT,ICOL)
+  110 CONTINUE
+      IF (ICOUNT .EQ. 1 .OR. ICOUNT .EQ. NPTS) THEN
+         TIM = 5.0
+         RETURN 
+      ENDIF
+      PHI = PHIOFF + (ICOUNT - 1)*PSTEP
+      TIM = 500.0*TIM/PCOUNT(ICOUNT)
+      IF (TIM .LT. 10000.0) THEN
+        IF (TIM .LT. 1000.) TIM = 1000.
+        PSTEP = PSTEP/4
+        IF (PSTEP .GT. STEPM) GO TO 100
+      ENDIF
+      RETURN
+      END