Re: Help with translation: Fortran77 => Ada95

[Colin Paul Gloster <Colin_Paul_Gloster@ACM.org>]

Sorry, I am tired and am not going to look through all of that now nor
really think of it in terms of the mathematical problem domain which could
produce a more elegant solution...especially the latter since it may just be
neater to forget about porting the FORTRAN and just write a function
which does as required.

However I have a suggestion, bearing in mind abhorrance of goto. Depending
on how mistaken I am, in F77 the continue keyword on line 110  is part of the
looping construct of do on line 105. I.e. m starts at one and each time it is
incremented it is incremented by the value of n (so m is not necessarily just
increased by one each time) and the loop is to be run one hundred and ten times
with continue signalling each next iteration.

-- more FORTRAN 77
-- Look for a small subdiagonal element.
--
  105   do 110 m=l,n
          if(m.eq.n) goto 120
          if(abs(e(m)).le.eps*(abs(zero(m))+abs(zero(m+1)))) goto 120
  110   continue
  120   p=zero(l)
-- more FORTRAN 77

So in your Ada95 version you could try something like (tidy this up
in to proper compilable Ada when you have decided what you will go for)
-- more F77 to be ported
MAX_LOOP_ITERATIONS := 110;
loop_iterations_so_far := 1; -- or 0, you may change this in your translating
m := 1;
while loop_iterations_so_far <= MAX_LOOP_ITERATIONS  and  m /= n  and (
abs(e(m)) <= eps*(abs(zero(m))+abs(zero(m+1))) ) loop
               m := m + n;
end loop;
-- more F77 to be ported

Bye,
Colin Paul Gloster