Re: Factorials on the 86
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Re: Factorials on the 86
This would not make a difference on a calculator. Memory does not
"magically" speed up a processor. The only reason it makes a difference on
a PC is because a PC swaps memory on the hard disk so it can simulate more
memory than it actually has, and most PC environments need more than 32MB
of memory.
And in case anybody would point out that a TI-85 or TI-86 runs slower
(overall) when it has less memory free, I will point out that it is not the
free memory that speeds up the calculator, but the used memory that slows
down the calculator, because it takes longer to search for a specific
variable or store to a variable.
The factorial function on the TI-86 probably has a smart algorithm so it
doesn't have to internally multiply 449 numbers, while the TI-85 just does
it the slow way.
________________
Jeff Tyrrill
http://tyrrill-ticalc.home.ml.org/
http://ti-philes.home.ml.org/
-----Original Message-----
From: Williams, Matt [SMTP:Williams.Matt@CON-WAY.COM]
Sent: Tuesday, February 17, 1998 11:42 AM
To: CALC-TI@LISTS.PPP.TI.COM
Subject: Re: Factorials on the 86
It's kind of like having a computer with 32MB of RAM vs a computer with
128MB of RAM trying to run something. The amount of memory available on
the calculator has a high correlation to the speed of the calculator.
Just for kicks, try a TI-85 with nothing on it vs a TI-86 that is
completely full and see which one is faster.
--
-iceboxman
TI-CALC Discoveries
http://ticd.home.ml.org
or
http://www.geocities.com/SiliconValley/Peaks/4152/index.html
iceboxman@geocities.com
>----------
>From: Todd Stanley[SMTP:toddestan@AOL.COM]
>Reply To: Todd Stanley
>Sent: Friday, February 13, 1998 1:33 PM
>To: CALC-TI@LISTS.PPP.TI.COM
>Subject: Factorials on the 86
>
>A few days ago I was fooling around with my 86's factorial function in
>math class, when I found that putting numbers that weren't integers
>didn't cause an error like on my 85 or my friend's 82. For example,
>10.5! spits out 11899423.084 instead of ERROR 04 DOMAIN. I read in the
>manual (pg. 294) that the calculator uses the "Gamma" function to
>evaluate non-integers when doing factorials. My math teacher had no
>clue what the manual is talking about and what the gamma function is.
>What is the Gamma function and what does it do (as in what does the
>number it give out mean)?
>
>Also, I noticed that the 86 is very much faster when evaluating
>factorials than the older 85. If you have an 85 and an 86, try
>evaluating 449! at the same time on both calculators. The 86 gives back
>an answer almost instantly, while the 85 takes a few seconds. Does the
>86 use a different way to computer factorials?
>
>Todd
>
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