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File: [Development] / JSOC / proj / timed / apps / sub_shift.f (download)
Revision: 1.1, Tue Nov 15 20:32:58 2011 UTC (11 years, 6 months ago) by rick
Branch: MAIN
CVS Tags: Ver_LATEST, Ver_9-5, Ver_9-41, Ver_9-4, Ver_9-3, Ver_9-2, Ver_9-1, Ver_9-0, Ver_8-8, Ver_8-7, Ver_8-6, Ver_8-5, Ver_8-4, Ver_8-3, Ver_8-2, Ver_8-12, Ver_8-11, Ver_8-10, Ver_8-1, Ver_8-0, Ver_7-1, Ver_7-0, Ver_6-4, Ver_6-3, Ver_6-2, Ver_6-1, Ver_6-0, HEAD

added for JSOC release 6.0

      SUBROUTINE shift(x,n,delta)
CC     x(n) is the original data array for shift.
CC     delta is the value to be shifted, and the 
CC     routine returns x(n) after shifting.
      DIMENSION x(n), y1((n+1)/2), y2((n+1)/2)
      DIMENSION y1_temp((n+1)/2),y2_temp((n+1)/2)
      REAL delta
CC     first is to divide x(n) into 2 sub-arrays
      DO 5 i=1, (n+1)/2
         y1(i)=x((n+1)/2+i-1)
         y2(i)=x((n+1)/2-i+1)
 5    CONTINUE
      
      IF(delta.GE.0.) THEN
 	 m=INT(delta)
	 del=delta-m
         DO 15 i=m+2, (n+1)/2
            y1_temp(i)=y1(i-m-1)+(y1(i-m)-y1(i-m-1))*(1-del)
            y2_temp(i)=y2(i-m-1)+(y2(i-m)-y2(i-m-1))*(1-del)
 15      ENDDO
	 DO 16 i=1, m+1
           y1_temp(i)=y1(1)-(y1(2)-y1(1))*(i+del-1)
           y2_temp(i)=y2(1)-(y2(2)-y2(1))*(i+del-1)
 16 	 ENDDO
         
      ELSE
	 m=INT(-delta)
	 del=-delta-m
         DO 20 i=1, (n+1)/2-(m+1)
            y1_temp(i)=y1(i+m)+(y1(i+m+1)-y1(i+m))*(del)
            y2_temp(i)=y2(i+m)+(y2(i+m+1)-y2(i+m))*(del)
 20      ENDDO
      ENDIF

      DO 25 i=1,(n+1)/2
         x(i)=y2_temp((n+1)/2-i+1)
         x(i+(n+1)/2-1)=y1_temp(i)
 25   ENDDO
      x((n+1)/2)=y1(1)
      
      RETURN
      END

Karen Tian