如何提高精度？

zyl

程序定义的变量是单精度，但是想提高计算精度。我把变量都定义成为REAL(KIND=8)之后，程序报实参与虚参不匹配，所以困惑了。给位大大，帮帮忙改下呗，谢谢谢谢！

[Fortran] syntaxhighlighter_viewsource syntaxhighlighter_copycode

PROGRAM MAIN 
   
 IMPLICIT NONE
 INTEGER I 
REAL T  
REAL  CCU,CNBSN 
REAL RES        
REAL*8 ACU,ASC  
REAL B,RRR  
REAL CAV 
REAL  t1,t2 
REAL*16  Q,F 
REAL y   
REAL Iop  
 F=0.000
 
 t1=0.0 
 Iop=8930.0 
 B=12.84
 RRR=150
 ACU=3.80233E-5 
 ASC=3.80233E-5
 t2=2.0
 y=5.0
 Q=Iop**2*y*(EXP(-2.0*y*t1/2.0)-EXP(-2.0*y*t2/2.0)) &
              /(2.0*Acu**2.0)
 WRITE(*,*) "Q=",Q
 DO I=1,11  
     T=89.0+(i-1)*0.1
     CALL CNB3SN(T,B,CNBSN)
     CALL CCCU(T,CCU)
     CALL DIANZULV(T,B,RRR,RES) 
     CAV=(CCU*ACU+CNBSN*ASC)/(ACU+ASC) 
      F=CAV*0.001/RES+F
END DO
STOP
END
    

SUBROUTINE CNB3SN(T,B,CNBSN)
IMPLICIT NONE
REAL   b4,b3,b2,b1,b0
REAL  T,B
REAL  CNBSN
   IF(T>0.0  .AND.  T<10.4 ) THEN
           b4=0.0
           b3=38.8-1.8*B+0.0634*B**2
           b2=-110*exp(-0.434*B)
           b1=207.0-3.83*B+2.86*B**2
           b0=0
         
   ELSEIF(T>10.4  .AND.  T<26.113 ) THEN    
           b4=0.0
           b3=7.42
           b2=0.0
           b1=1522.0
           b0=0.0
  ELSEIF(T>=26.113 .AND. T<169.416) THEN 
           b4=0.0
           b3=0.0
           b2=-61.635
           b1=19902.0
           b0=-305807.0 
  ELSEIF(T>=169.416 .AND. T<300.0) THEN  
           b4=0.0
           b3=0.0
           b2=-7.4636
           b1=4411.0
           b0=763801.0
  ELSE
             b4=0.0
             b3=0.0
             b2=0.0
             b1=0.0
             b0=1415377.0
  ENDIF
         CNBSN=b4*(T**4)+b3*(T**3)+b2*(T**2)+b1*T+b0
  RETURN
  END   
SUBROUTINE CCCU(T,CCU)
IMPLICIT NONE
REAL a0,a1,a2,a3,a4,a5,a6,a7
REAL dens,aa1,aa2,aa3,aa4,aa
REAL T
REAL CCU
a0=-1.91844
a1=-0.15973
a2=8.61013
a3=-18.996
a4=21.9661
a5=-12.7328
a6=3.54322
a7=-0.3797
aa1=a0*((log10(T))**0.0)+a1*((log10(T))**1.0)
aa2=a2*((log10(T))**2.0)+a3*((log10(T))**3.0)
aa3=a4*((log10(T))**4.0)+a5*((log10(T))**5.0)   
aa4=a6*((log10(T))**6.0)+a7*((log10(T))**7.0)
aa=aa1+aa2+aa3+aa4 
dens=8960.0  
  CCU=dens*(10.0**aa)*1.0
 WRITE(*,*) "CCU=",CCU
 RETURN
 END
    
   
SUBROUTINE DIANZULV(T,B,RRR,RES)    
REAL RES1,RES2,RES3,RES
    RES1=1.7E-8/RRR
    RES2=1.0E-8/(2.33*10**9/T**5+9.57*10**5/T**3+163.0/T)
    RES3=(0.37E-10+0.0005E-10*RRR)*B
    RES=RES1+RES2+RES3
    RETURN
    END

pasuka

不想修改程序的话，可以通过添加编译器的编译指令实现
譬如gfortran可以参考 https://gcc.gnu.org/onlinedocs/g ... ran-Dialect-Options
-fdefault-real-8
Set the default real type to an 8 byte wide type. This option also affects the kind of non-double real constants like 1.0, and does promote the default width of DOUBLE PRECISION to 16 bytes if possible, unless -fdefault-double-8 is given, too. Unlike -freal-4-real-8, it does not promote variables with explicit kind declaration.
或者
-freal-4-real-8
-freal-4-real-10
-freal-4-real-16
-freal-8-real-4
-freal-8-real-10
-freal-8-real-16
Promote all REAL(KIND=M) entities to REAL(KIND=N) entities. If REAL(KIND=N) is unavailable, then an error will be issued. All other real kind types are unaffected by this option. These options should be used with care and may not be suitable for your codes. Areas of possible concern include calls to external procedures, alignment in EQUIVALENCE and/or COMMON, generic interfaces, BOZ literal constant conversion, and I/O. Inspection of the intermediate representation of the translated Fortran code, produced by -fdump-tree-original, is suggested.

zyl

已解决，谢谢！