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50g User RPL Micro-Challenge: Fraction to a Power - Joe Horn - 10-09-2017 10:26 AM
The 50g in exact mode takes a very long time to raise a fraction (ratio of integers) to integer powers. Example: 11/12 to the 115th power:
11/12
115
<< ^ EVAL >>
takes about 40 seconds to return the exact answer.
Micro-Challenge: Generate that same answer in less than 1 second, using only vanilla User RPL (no System RPL or SYSEVALs or FLASHEVALs etc). The fastest program wins.
RE: 50g User RPL Micro-Challenge: Fraction to a Power - Gerald H - 10-09-2017 11:16 AM
My suggestion:
0.2197s
Code:
« SWAP OBJ→ 5.
ROLLD DROP SWAP
PICK3 ^ SWAP ROT ^
ROT 3. →ALG
»RE: 50g User RPL Micro-Challenge: Fraction to a Power - Werner - 10-09-2017 11:20 AM
The date on my IPOW.RPL file reads 2006 ;-)
Edit: but it can't get it done in less than 1 second, so Gerald's idea is the way to go!
Werner
RE: 50g User RPL Micro-Challenge: Fraction to a Power - John Keith - 10-09-2017 12:15 PM
While Gerald H's program is probably unbeatable, I'm guessing this
Code:
\<<SWAP OBJ\-> DROP2 UNROT OVER ^ UNROT ^ / \>>is closer to what Joe has in mind, since it takes around 945ms on my HP 50.
John
RE: 50g User RPL Micro-Challenge: Fraction to a Power - Gerald H - 10-09-2017 12:46 PM
With John's better stack manipulation:
: .2186Code:
« SWAP OBJ→ 5.
ROLLD DROP UNROT
OVER ^ UNROT ^ ROT
3. →ALG
»RE: 50g User RPL Micro-Challenge: Fraction to a Power - Gerald H - 10-09-2017 12:48 PM
I don't know where the face came from - I entered ":s:" without quotes.
RE: 50g User RPL Micro-Challenge: Fraction to a Power - Gerson W. Barbosa - 10-09-2017 01:17 PM
(10-09-2017 12:48 PM)Gerald H Wrote: I don't know where the face came from - I entered ":s:" without quotes.
Just check “Disable Smilies” in the Post Options.
:s:
RE: 50g User RPL Micro-Challenge: Fraction to a Power - Gerald H - 10-09-2017 02:34 PM
Faster:
:s: .1831
Code:
« SWAP COMP→ 5.
ROLLD 5. ROLLD
UNROT OVER ^ UNROT
^ 4. ROLL 4. ROLL
→ALG
»RE: 50g User RPL Micro-Challenge: Fraction to a Power - Gerald H - 10-09-2017 02:35 PM
Thank you, Gerson, it worked.
RE: 50g User RPL Micro-Challenge: Fraction to a Power - Gerald H - 10-09-2017 02:46 PM
Faster?
:s: .1825
Code:
« SWAP COMP→ 5.
ROLLD 4. ROLLD
UNROT OVER ^ UNROT
^ ROT 4. ROLL →ALG
»RE: 50g User RPL Micro-Challenge: Fraction to a Power - Gilles59 - 10-09-2017 03:22 PM
Code:
<< SWAP FXND UNROT OVER ^ UNROT ^ / >>0.9282s
Gerald solution is very fast ! (but needs development Library ;D ) I wonder why it s so fast ?
RE: 50g User RPL Micro-Challenge: Fraction to a Power - Gerald H - 10-09-2017 03:30 PM
It's the division that's so slow.
RE: 50g User RPL Micro-Challenge: Fraction to a Power - Gerald H - 10-09-2017 03:34 PM
This version is about as fast as my last try:
Code:
« SWAP FXND UNROT
OVER ^ UNROT ^ { /
} OBJ→ DROP 3. →ALG
»RE: 50g User RPL Micro-Challenge: Fraction to a Power - Gilles59 - 10-09-2017 03:44 PM
(10-09-2017 03:30 PM)Gerald H Wrote: It's the division that's so slow.
Because a direct '/' tries to simplify the fraction?
and ->ALG does not try ?
RE: 50g User RPL Micro-Challenge: Fraction to a Power - Gerald H - 10-09-2017 06:24 PM
Average over 100 runs
.182s
Code:
« SWAP COMP→ DROP 4
ROLLD UNROT OVER ^
UNROT ^ ROT 3. →ALG
»RE: 50g User RPL Micro-Challenge: Fraction to a Power - Arno K - 10-09-2017 09:39 PM
Replacing ->ALG by EVAL increases the time my program Needs (.2163s) to .9723s.
Arno
RE: 50g User RPL Micro-Challenge: Fraction to a Power - Joe Horn - 10-09-2017 10:01 PM
(10-09-2017 12:15 PM)John Keith Wrote: While Gerald H's program is probably unbeatable, I'm guessing this
Code:
\<<SWAP OBJ\-> DROP2 UNROT OVER ^ UNROT ^ / \>>
is closer to what Joe has in mind, since it takes around 945ms on my HP 50.
John
I had these two in mind (both contain 8 commands):
<< SWAP OBJ-> DROP ->LIST SWAP ^ EVAL / >>
<< SWAP FXND UNROT OVER ^ UNROT ^ / >>
... but both suffer from the division at the end (yes, Gilles, division simplifies fractions, which isn't needed here). That's why Gerald's program is so fast.
RE: 50g User RPL Micro-Challenge: Fraction to a Power - brickviking - 10-09-2017 10:37 PM
(10-09-2017 10:26 AM)Joe Horn Wrote: The 50g in exact mode takes a very long time to raise a fraction (ratio of integers) to integer powers. Example: 11/12 to the 115th power:
11/12
115
<< ^ EVAL >>
takes about 40 seconds to return the exact answer.
Micro-Challenge: Generate that same answer in less than 1 second, using only vanilla User RPL (no System RPL or SYSEVALs or FLASHEVALs etc). The fastest program wins.
On my calculator, putting that onto the stack and using this: [RSHIFT] →NUM gives me the answer in less than a second.
(Although in saying that, if I hit EVAL instead, that takes a while, and gives me a fraction with really REALLY long numbers.)
I don't know if my answer counts as RPL or not.
(whistles innocently)
(Post 113)
RE: 50g User RPL Micro-Challenge: Fraction to a Power - ttw - 10-10-2017 01:20 AM
I tried
<< (11^115)/(12^115) EVAL>> TEVAL
which took 2.5 sec. Seems like a lack of optimization in the expression parser.
RE: 50g User RPL Micro-Challenge: Fraction to a Power - Joe Horn - 10-10-2017 04:12 AM
(10-09-2017 10:37 PM)brickviking Wrote:(10-09-2017 10:26 AM)Joe Horn Wrote: The 50g in exact mode takes a very long time to raise a fraction (ratio of integers) to integer powers. Example: 11/12 to the 115th power:
11/12
115
<< ^ EVAL >>
takes about 40 seconds to return the exact answer.
Micro-Challenge: Generate that same answer in less than 1 second, using only vanilla User RPL (no System RPL or SYSEVALs or FLASHEVALs etc). The fastest program wins.
On my calculator, putting that onto the stack and using this: [RSHIFT] →NUM gives me the answer in less than a second.
Not the exact answer, which is what was specified.