Hi, everybody,

The following two functions FACTORIAL and FACTORIAL2, both of which
can work very well. Is FACTORIAL F90/F95 Standard conforming?

module mod1
contains
function factorial(n)
implicit none
integer :: n, factorial

factorial = n * temp(n-1)
end function factorial

function temp( n )
implicit none
integer n, temp

I have some code with user defined data types that have pointer
arrays. I don't really use them as pointers, they are really just
allocated and used in the normal way. Now, most of my compilers
support the allocatable TR, so I'm switching these to allocatable
arrays in the declarations.

When compiling this code with gfortran, I came across the following
situation involving intent(out) dummy arguments. My code apparently
works with pointer components, but it gives me a bus error when I
use allocatable components. If I change the intent(out) to
intent(inout) in the dummy declaration, then both versions
apparently work.

The following short program demonstrates this. On MacOSX 10.5.2
with gfortran 4.3.0, the code errs after the first call.
With several other compilers (including the ABSOFT 9.2 compiler on
PPC and the intel ifort 10.1 compiler on intel) both calls
apparently succeed.

Hi All,

I am building some 3D grids for visualization starting from a much
bigger grid. I build these grids by satisfying certain conditions on
x, y, z coordinates of their cells.
Basically, for every cell I have the coordinates of its center point
(centroids), named xCent, yCent and zCent. These values are stored in
arrays (i.e., if I have 10,000 cells, I have 3 vectors xCent, yCent
and zCent with 10,000 values in them). What I'd like to do is to find
the indices for which all these 3 conditions are satisfied:

! Filter cells which do not satisfy Z requirements:
zMin <= zCent <= zMax

! Filter cells which do not satisfy Y requirements:
yMin <= yCent <= yMax

! Filter cells which do not satisfy X requirements:
xMin <= xCent <= xMax

I'd like to end up with a vector of indices which tells me which are
the cells in the original grid that satisfy all 3 conditions. I have
implemented 2 different solutions in Fortran (see below), but they are
both slower than a pure Python-NumPy implementation like this: