fortran77

I understand gfortran can compile f90 or f95? How does it know which one it is compiling? Also can it compile f77 code? Does ubuntu already have a fortran compiler or do I need to download gfortran? Jonathan Dursi gfortran can guess certain things from the file extension; if the file has an extension of .f, .f90, f95, .f03, or .f08 it will assume fixed (.f) or free format with the appropriate standards. But you can force it to compile (say) fortran2003 code with the option -std=f2003. Eg, from the documentation , -std=std Specify the standard to which the program is expected to conform, which

I'm using gfortran [GNU Fortran (GCC) 4.8.3 20140911 (Red Hat 4.8.3-7)] on a Fedora 20 x86_64 to compile a bunch of Fortran 77 code which refers to 'iargc' function in the following manner: bin2D2nc.f:31: integer iargc,strlen1 bin2D2nc.f:32: external iargc,strlen1 bin2D2nc.f:44: i=iargc() When the make script reaches the compilation comand bellow, gfortran -O3 -ffixed-line-length-132 -fall-intrinsics -I/home/santiago/Install/netcdf_sam/include -o bin2D2nc -I./SRC ./SRC/bin2D2nc.f ./SRC/hbuf_lib.f ./SRC/cape.f ./SRC/cin.f -L/home/santiago/Install/netcdf_sam/lib -lnetcdf -L/usr/lib64 -lpthread I

What is the motivation for defining PI as PI=4.D0*DATAN(1.D0) within Fortran 77 code? I understand how it works, but, what is the reasoning? This style ensures that the maximum precision available on ANY architecture is used when assigning a value to PI. Because Fortran does not have a built-in constant for PI . But rather than typing in the number manually and potentially making a mistake or not getting the maximum possible precision on the given implementation, letting the library calculate the result for you guarantees that neither of those downsides happen. These are equivalent and you'll

I do not want to use common blocks in my program. My main program calls a subroutine which calls a function. The function needs variables from the subroutine. What are the ways to pass the set of information from the subroutine to the function? program ... call CONDAT(i,j) end program SUBROUTINE CONDAT(i,j) common /contact/ iab11,iab22,xx2,yy2,zz2 common /ellip/ b1,c1,f1,g1,h1,d1,b2,c2,f2,g2,h2,p2,q2,r2,d2 call function f(x) RETURN END function f(x) common /contact/ iab11,iab22,xx2,yy2,zz2 common /ellip/ b1,c1,f1,g1,h1,d1,b2,c2,f2,g2,h2,p2,q2,r2,d2 end What you care about here is association :