On 16 June 2011 20:53, Tony Duell <ard at p850ug1.demon.co.uk> wrote:
-tony (Who can't use an infix calculator).
Really? So you can't read or write algebraic equations, either?
YEs, I can. but actually, I find postfix notation a lot clearer and more
logical.
When it comes to using a calcualtor, I find that if I try to use an infix
one, I am forver prssign the keys in the wrong order (as in 'OK, I want
to halve that result' and will press the 2 before the divide key, thus
reasign the result on an infix machine).
With an infix machine, I have to think what I am doing all the time, with
an RPN machine, it's automatic.
And that's not to mention the fact that on an RPN machine I know exactly
what will happen when I press a key (the operaion will be executed there
and then, noting is stored for later use), wehreas on an infix machien I
have ot think 'does this machien obey the heirarchy rules, and if so,
which ones).
In otehr words, on an ifix machine, I have to think what '1+2*3' will
evaluate to, on an RPN machine I know exactly what 1 2 3 * + or
1 2 + 3 * will do.
Because if you can type it, you have therefore shown that can press
buttons in that order - which is how calculators work.
Firsltym not it isn't (see above) amd secondly, it appears that you and I
use claculators in differnet ways. Very often I don't have an expression
to evaulate. It's more a matter of 'Let's work out the reactance of that
cpaactiro at this frequency. Now let's add on (in quadrature) the total
resistance of that chaim. Now let's work out...' That sort of thing is
much easier on an RPN machine, I can assure you.
Personally, at a wet-behind-the-ears 43y old, I've
never used an RPN
calculator, but I know that I don't really understand RPN and trying
to unpack equations and rewrite them in RPN was extremely hard work
for me...
Odd. It took me less than an afternoon to learn it about 30 years ago.
And I am darn glad I did.
-tony