new RPNenh page (2009)
The 3 display modes
Most calulators provide the usual "FIX" and "ENG" mode... these are very classic.
RPNenh provide other non-obvious mode.
To see an example how the rational mode is usefull, just try the following :
put this matrix on the staxk
|examples mode :
||may round if number too near an interget
||like cute and try to make it rational or with pi..
[[1 2 3][4 5 6][-1 2 3]] and use
1/x, in rational mode you will get the following :
[ [ 1/2 0. -1/2 ]
[ -3. 1. 1. ]
[ 13/6 -2/3 -1/2 ] ]
it's nice, isn't it ?
this mode just display number exactly as it is in memory.
no rounding is applyed.
The default mode is "cute", because it's fast.
Rational mode is more accurate but is a little bit slower.
"cute" in interresting to to avoid displaying computer error-round, for ex. system may gives 5.00000000112 instead of 5.
Rational try to find a combinaison with PI, technicaly it try to find "number = P*pi/Q" where P and Q are integer.
system also try some classic squares, technicaly it try to match with "number = R*sqr(S)" where R and S are integer.
system canot find for Q, P, R and S too high.
finaly it try to find N and M that match "number= N/M". if nothing is found, system just display "number" as it is.
That means rational cannot give things like "(1+sqr(5))/3" or "ln(2-sqr(2))"...
the reason is : it's just a digital calculator, not an algebraic one!
System changing mode
just click on small icons on upper-right of RPNEnh.
If you want to learn everything about user interface, just checkthis tutorial It also show you where you can find the mode buttons.
Goto : RPNEnh menu - ScreenShots - List of functions