Pointers and dynamic data structures in Fortran 90/95
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From: deltaquattro on 17 May 2006 08:07 Hi, I am an engineer and for my job I need learn how to use pointers and dynamic data structures in Fortran 90/95. I know Fortran 77 and I have a good reference for Fortran 90/95, "Fortran 90/95 for Scientists and Engineers" by Stephen J. Chapman, 2nd ed. 2004. However, my problem is not the language itself, but the fact that I never programmed with pointers. I need some references which teaches how to do this, either using Fortran 90, or at least from a generic point of view, without referring to any particular languages. Instead, almost everything I found uses C or C++, and I'd rather not learn yet another language, since I already have to learn Fortran 90/95. Can you indicate something useful? Thank you very much, Greetings, Sergio Rossi
From: Arjen Markus on 17 May 2006 08:17 As a rule-of-thumb I think you can look at pointers as "aliases": Pointers in Fortran have a lot of information associated with them about the data object they point to. That is: they do not merely point to some address, but they can actually be queried about the size of the data object. For instance: real, dimension(:), pointer :: p real, dimension(100) :: array p => array write(*,*) size(p), size(array) ! The same size is printed p => array(1:20) write(*,*) size(p), size(array) ! 20 and 100 are printed You can also use different strides: p => array(1:100:2) ! Points to the elements 1, 3, ,,, in the original array write(*,*) size(p) ! Should print 50 In almost all respects p acts as a different name for the original variable "array" array = 0.0 p(1) = 1.0 write(*,*) array(1) ! Prints 1 Regards, Arjen
From: Tom Micevski on 17 May 2006 08:30 Arjen Markus wrote: > As a rule-of-thumb I think you can look at pointers as "aliases": > > Pointers in Fortran have a lot of information associated with them > about the > data object they point to. > > That is: they do not merely point to some address, but they can > actually be > queried about the size of the data object. > > For instance: > > real, dimension(:), pointer :: p > real, dimension(100) :: array shouldn't a target (attribute?) be included? real, dimension(100), target :: array
From: Michael Metcalf on 17 May 2006 08:59 "deltaquattro" <deltaquattro(a)hotmail.it> wrote in message news:1147867626.315048.128110(a)i40g2000cwc.googlegroups.com... > Hi, > > I am an engineer and for my job I need learn how to use pointers and > dynamic data structures in Fortran 90/95. We can offer an extended example showing all the principles at ftp.numerical.rl.ac.uk/pub/MRandC/pointer.f90. Regards, Mike Metcalf
From: Arjen Markus on 17 May 2006 09:06
Oops, yes, you are right. Regards, Arjen |