*-- Author : I.O. Skillicorn
      SUBROUTINE FTFHQQ(NPLA,IPA,SD,ZVV,C1,C2,C3,
**: FTFHQQ 40000 IS. New linking code.                                                                        
**----------------------------------------------------------------------                                      
C     LEAST SQUARES FIT IN R-Z, PHI-Z                                                                         
C     FOR SINGLE LINE SEGMENT                                                                                 
C     AUTHOR   I.O.SKILLICORN                                                                                 
C     RECODED 13/6/93                                                                                         
*KEEP,FRDIMS.                                                                                                 
*KEEP,FH1WORK.                                                                                                
*    Planar geometry                                                                                          
*                                                                                                             
*    Radial geometry                                                                                          
*                                                                                                             
*    Radial data...                                                                                           
*                                                                                                             
*    Planar Data                                                                                              
*                                                                                                             
*    Pointers into DIGI bank for IOS labelled hits                                                            
*                                                                                                             
*    Track segment data                                                                                       
*                                                                                                             
*    Fit data                                                                                                 
*                                                                                                             
*                                                                                                             
*KEND.                                                                                                        
*                                                                                                             
*KEEP,FPTVTX.                                                                                                 
**the common/VERTEX/ becomes /VERTVV/ (in analogy to /VERTFF/) on the                                         
** 17/6/91, since it is in conflict with the VERTEX module (g.bernardi)                                       
** (note that all these common names should start by F in this deck...)                                       
*KEEP,FRWERR.                                                                                                 
*KEND.                                                                                                        
*                                                                                                             
C     J IS POINT NO.     K=PLANE NO.                                                                          
C      PRINT1003,II,J,XX(II),YY(II),WP(II)                                                                    
      CALL FTLFTW(XX,YY,WP,II,0,2,RZS,RZII,ET,DRZS,DRZI,COV)
C     WEIGHTED MEAN R                                                                                         
C                                                                                                             
C     CALCULATE PHI BASED ON FITTED R                                                                         
C     J IS POINT NO.     K=PLANE NO.                                                                          
C     USE RESULTS OF STR LINE FIT IN R-Z                                                                      
C     LAB PHI WITH FITTED R                                                                                   
C     TRY MEAN R INSTEAD OF RR  - R1                                                                          
C     TAKE ERROR IN PHI PROPORTIONAL TO 1./RR                                                                 
C     PRINT1002,J,II,XX(II),YY(II),WP(II),RR                                                                  
C                                                                                                             
      CALL FTLFTW(XX,YY,WP,II,0,2,RPCOS,PHZ,EL,DRPCOS,DPHZ,COV)
C     RPCOS-SLOPE PHI-Z,PHZ-INTERCEPT  PHI AXIS                                                               
C     ERROR IN RPCOS IS UNKNOWN DUE TO R-MEASUREMENT PROBLEMS                                                 
CDEB  PRINT5000,RPCOS,PHZ,DRPCOS,DPHZ                                                                         
*