Need to convert FIF49 to Prime version

[BruceH]

There is an alternate approach which is to use 3 element lists to represent feet, inches and fractions of inches.

For example, the 15' 9-1/2" wall from earlier is entered as {15,9,1/2} (which displays as {15,9,0.5} but pressing [a b/c] turns the 0.5 back to a fraction).

Addition, subtraction and multiplication by a constant work as expected e.g. '3 * {0,14,5/8}' gives {0,42,1.875} which then just needs to be 'normalised'.

The function FIF does this normalisation:

Code:

EXPORT FIF(m)
BEGIN
  LOCAL res := {0,0,0};
  LOCAL in;
  in := ΣLIST(m * {12,1,1});
  res(1) := IP(in/12);
  res(2) := IP(in MOD 12);
  res(3) := FP(in);
  RETURN res;
END;

The full windows-in-wall example can be calculated as: ({15,9,1/2}-3*{0,14,5/8})/4 -> {3.75,-8.25,-0.34375} and then FIF(Ans) -> {3, 0, 13/32}

It is an easy matter to modify the code to use fixed 8ths or 16ths for the third value in the list if so desired.