Hi M8.. I really am crap at some aspects of math..
...
I just use Visual Basic or Calc and formulas in the spread sheet LOL !!
I might be asking you guys for plenty advice soon..like line interpolation of 3d mapping in engine management units etc...
I just usually nick someone elses code ...
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Me dad was a maths teacher before he retired, but lives on the Isles of Scilly and dont have email or fax...
This one doood, I cant help...
Joe.