C INTE22    SOURCE    CHAT      05/01/13    00:39:53     5004           
      SUBROUTINE INTE22(PRT,PRF,T0,FT0,LON)                                     
      IMPLICIT INTEGER(I-N)
      IMPLICIT REAL*8(A-H,O-Z)                                                  
C                                                                               
C  ====================================================================         
C  =         INTERPOLATION LINEAIRE    RECHERCHE PAR DICHOTOMIE       =         
C  = CREATION    14/01/86                                             =         
C  = PROGRAMMEUR GUILBAUD                                             =         
C  ====================================================================         
C                                                                               
-INC CCOPTIO                                                                    
      DIMENSION PRT(1),PRF(2)                                                   
      DATA EPSI/1.D-10/                                                         
      N1=1                                                                      
      N2=LON                                                                    
    1 CONTINUE                                                                  
      N2N1=N2-N1                                                                
      IF(N2N1.EQ.1) GOTO 2                                                      
      NC=(N1+N2)/2                                                              
      IF(T0.LT.PRT(NC)) THEN                                                    
        N2=NC                                                                   
      ELSE                                                                      
        N1=NC                                                                   
      ENDIF                                                                     
      GOTO 1                                                                    
    2 CONTINUE                                                                  
      ALPHA=(T0-PRT(N1))/(PRT(N2)-PRT(N1))                                      
      FT0=ALPHA*(PRF(N2)-PRF(N1))+PRF(N1)                                       
      BETA=1.D0-ALPHA                                                           
      IF(BETA.LT.EPSI)FT0=PRF(N2)                                               
      RETURN                                                                    
      END