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Nyx Alsop

Registered User

Join date: 14 Dec 2008

Posts: 252

01-19-2010 15:05

integer my = 4^8;

= 12

--

float my = 4^8;
llSay(0, (string)my);

= 12.00

--

I'm trying to do a number to the power of.

I'm sure I need to just write something differently, anyhelp?

Lazink Maeterlinck

Registered User

Join date: 8 Nov 2005

Posts: 332

01-19-2010 15:11

use llPow(float base, float exponent)

integer my = llPow(4,

;

Talarus Luan

Ancient Archaean Dragon

Join date: 18 Mar 2006

Posts: 4,831

01-19-2010 15:13

^ is the bitwise XOR operator.

There is no "Power" operator, just the function.

Twisted Pharaoh

if ("hello") {"hey hey";}

Join date: 24 Mar 2007

Posts: 315

01-19-2010 15:35

If you are using powers of two, you can use bit shift operations:

1 << z = 2^z

and (x*y)^z = x^z * y^z

In your case you can write:

integer x = 4 ;
integer pow = 8 ;
integer y = 1 << pow ; // 2^pow

llOwnerSay("4^8="+(string)(y*y)); //4^pow = 2^pow * 2^pow ;

It's a bit more complicated but makes things tremendously faster

Johan Laurasia

Fully Rezzed

Join date: 31 Oct 2006

Posts: 1,394

01-19-2010 20:55

sitting here waiting for Void to chime in with a faster way....

Void Singer

Int vSelf = Sing(void);

Join date: 24 Sep 2005

Posts: 6,973

01-19-2010 22:41

faster than a bitshift? pfft

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Ziggy Puff

Registered User

Join date: 15 Jul 2005

Posts: 1,143

01-21-2010 09:50

This is faster than a bitshift:

llOwnerSay("4^8=65536"

;

Somebody had to say it

Void Singer

Int vSelf = Sing(void);

Join date: 24 Sep 2005

Posts: 6,973

01-21-2010 10:10

thanks Ziggy I needed that laugh, more's the shame I didn't think of it first =P

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Argent Stonecutter

Emergency Mustelid

Join date: 20 Sep 2005

Posts: 20,263

01-21-2010 10:19

I wrote a program once using bit-shifts and adds to do all the multiplication on a PDP-11, made the inner loop about 10x faster. Later, on a RISC chip, the same optimizations made it 2x slower. Because integer multiply was no longer the bottleneck... the sheer number of instructions was.

So I say... time it. Don't assume.

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Argent Stonecutter - http://globalcausalityviolation.blogspot.com/

"And now I'm going to show you something really cool."

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Meade Paravane

Hedgehog

Join date: 21 Nov 2006

Posts: 4,845

01-21-2010 10:21

Power tutorial: http://www.youtube.com/watch?v=z33tH-JdPDg

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Void Singer

Int vSelf = Sing(void);

Join date: 24 Sep 2005

Posts: 6,973

01-21-2010 11:15

From: Argent Stonecutter

So I say... time it. Don't assume.

agreed... and keep timing it. just because the front end hasn't changed, the back end might (and has in the past with LSL)

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Twisted Pharaoh

if ("hello") {"hey hey";}

Join date: 24 Mar 2007

Posts: 315

01-21-2010 14:34

Yeah, not to mention some compilers optimisations can be more efficient than what you've done manually.

I need help, To the POWER
Nyx Alsop Registered User Join date: 14 Dec 2008 Posts: 252	01-19-2010 15:05 integer my = 4^8; = 12 -- float my = 4^8; llSay(0, (string)my); = 12.00 -- I'm trying to do a number to the power of. I'm sure I need to just write something differently, anyhelp?
Lazink Maeterlinck Registered User Join date: 8 Nov 2005 Posts: 332	01-19-2010 15:11 use llPow(float base, float exponent) integer my = llPow(4, ;
Talarus Luan Ancient Archaean Dragon Join date: 18 Mar 2006 Posts: 4,831	01-19-2010 15:13 ^ is the bitwise XOR operator. There is no "Power" operator, just the function.
Twisted Pharaoh if ("hello") {"hey hey";} Join date: 24 Mar 2007 Posts: 315	01-19-2010 15:35 If you are using powers of two, you can use bit shift operations: 1 << z = 2^z and (xy)^z = x^z y^z In your case you can write: integer x = 4 ; integer pow = 8 ; integer y = 1 << pow ; // 2^pow llOwnerSay("4^8="+(string)(yy)); //4^pow = 2^pow 2^pow ; It's a bit more complicated but makes things tremendously faster
Johan Laurasia Fully Rezzed Join date: 31 Oct 2006 Posts: 1,394	01-19-2010 20:55 sitting here waiting for Void to chime in with a faster way....
Void Singer Int vSelf = Sing(void); Join date: 24 Sep 2005 Posts: 6,973	01-19-2010 22:41 faster than a bitshift? pfft _____________________ \| \| . "Cat-Like Typing Detected" \| . This post may contain errors in logic, spelling, and \| . grammar known to the SL populace to cause confusion \| \| - Please Use PHP tags when posting scripts/code, Thanks. \| - Can't See PHP or URL Tags Correctly? Check Out This Link... \| -
Ziggy Puff Registered User Join date: 15 Jul 2005 Posts: 1,143	01-21-2010 09:50 This is faster than a bitshift: llOwnerSay("4^8=65536"; Somebody had to say it
Void Singer Int vSelf = Sing(void); Join date: 24 Sep 2005 Posts: 6,973	01-21-2010 10:10 thanks Ziggy I needed that laugh, more's the shame I didn't think of it first =P _____________________ \| \| . "Cat-Like Typing Detected" \| . This post may contain errors in logic, spelling, and \| . grammar known to the SL populace to cause confusion \| \| - Please Use PHP tags when posting scripts/code, Thanks. \| - Can't See PHP or URL Tags Correctly? Check Out This Link... \| -
Argent Stonecutter Emergency Mustelid Join date: 20 Sep 2005 Posts: 20,263	01-21-2010 10:19 I wrote a program once using bit-shifts and adds to do all the multiplication on a PDP-11, made the inner loop about 10x faster. Later, on a RISC chip, the same optimizations made it 2x slower. Because integer multiply was no longer the bottleneck... the sheer number of instructions was. So I say... time it. Don't assume. _____________________ Argent Stonecutter - http://globalcausalityviolation.blogspot.com/ "And now I'm going to show you something really cool." Skyhook Station - http://xrl.us/skyhook23 Coonspiracy Store - http://xrl.us/coonstore
Meade Paravane Hedgehog Join date: 21 Nov 2006 Posts: 4,845	01-21-2010 10:21 Power tutorial: http://www.youtube.com/watch?v=z33tH-JdPDg _____________________ Tired of shouting clubs and lucky chairs? Vote for llParcelSay!!! - Go here: http://jira.secondlife.com/browse/SVC-1224 - If you see "if you were logged in.." on the left, click it and log in - Click the "Vote for it" link on the left
Void Singer Int vSelf = Sing(void); Join date: 24 Sep 2005 Posts: 6,973	01-21-2010 11:15 From: Argent Stonecutter So I say... time it. Don't assume. agreed... and keep timing it. just because the front end hasn't changed, the back end might (and has in the past with LSL) _____________________ \| \| . "Cat-Like Typing Detected" \| . This post may contain errors in logic, spelling, and \| . grammar known to the SL populace to cause confusion \| \| - Please Use PHP tags when posting scripts/code, Thanks. \| - Can't See PHP or URL Tags Correctly? Check Out This Link... \| -
Twisted Pharaoh if ("hello") {"hey hey";} Join date: 24 Mar 2007 Posts: 315	01-21-2010 14:34 Yeah, not to mention some compilers optimisations can be more efficient than what you've done manually.

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