@Bo
Went step by step through that biquadratic function ...
and understoodits components.
Was totally unaware of that formula (shame on me);
could you cite a source, that sounds like an interesting book..?
-M
At 2018-09-04 12:24, you wrote:
  ([: %&4 [: %: *:@:(+/@:^)&2 - +:@:(+/@:^)&4) 3 4 5
As the square of the area of a triangle is a
symmetric polynomial of the squares of the
sides, the above tacit code also works.Â
Den tirsdag den 4. september 2018 13.51.07
CEST skrev Martin Kreuzer <i...@airkreuzer.com>:
Hi all -
To calculate the area of a flat triangle, using Heron's formula,
A(a,b,c)= sqrt( s2*(s2-a)*(s2-b)*(s2-c) )
I wrote a simple function doing this:
* get the three sides (as list input y)
* compute the half perimeter s2
* build the differences s2-y
* build product
* take square root
My explicit solution looks like this
taher=: 13 : '%: s2 * */ s2-y [ s2=. -: +/ y'
and works
  taher 3 4 5
Suggested tacit version looks like this (and works too)
tahert=: [: %: ([: -: +/) * [: */ ([: -: +/) - ]
Q: Is there a way to reference the intermediate result of ([: -: +/)
the half perimeter s2
within the tacit expression, as has been done in the explicit..?
[Guess the interpreter takes care of this anyway; my question aims at
whether a shorter formulation could be reached.]
Thanks
-M
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