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Re: Dashboard effect in Java application

the following code

int n = 100000;
long start = System.currentTimeMillis();
double k = Math.PI/180;
for(int i = 0; i < n; i++){
double angle = 180*Math.random();
double cosa = Math.cos(angle*k);
double sina = Math.sin(angle*k);
double arccosa = Math.acos(cosa);
}
long end = System.currentTimeMillis();
System.out.println("per cycle "+(double)(end-start)/(double)n);

reports about 0.003

that means that that time is really much less than painting time
so using lookup tables for trig functions won't give any significant gain in performance

thanks

On Dec 21, 2004, at 10:56 PM, Tom Davies wrote:

I meant a lookup table of the results of evaluating trigonometrical
functions like sin and cos

Tom

On Tue, 21 Dec 2004 22:52:26 -0500, Dmitry Markman <email@hidden> wrote: 
I'm not very familiar with image's lookup tables
but I thought it's related to the color conversion
cube transition has nothing to do with color conversion

or maybe you mentioned other lookuptable
so I didn't get it again :-(

thanks


On Dec 21, 2004, at 4:38 PM, Tom Davies wrote:

On Tue, 21 Dec 2004 16:10:34 -0500, Dmitry Markman <email@hidden>
wrote:


On Dec 21, 2004, at 3:19 PM, Levi Yourchuck wrote:

A couple of points on :

Have you considered putting in a table for the trig functions? 
if I understand right your question: you can trigger the changing by
clicking right bottom corner of the table


I'm pretty sure Levi meant a precomputed look-up table.

Tom

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Dmitry Markman




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References: 
 >Re: Dashboard effect in Java application (From: Tom Davies <email@hidden>)



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