commons-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Adam Hardy <adam...@cyberspaceroad.com>
Subject Re: [math] algorithm to establish value of parameter giving max value of equation
Date Thu, 29 May 2008 10:38:23 GMT
Adam Hardy on 29/05/08 11:18, wrote:
> luc.maisonobe@free.fr on 29/05/08 10:24, wrote:
>> In the previous message, I called twr what was really twrPrime, and I 
>> used a too slow method to compute it with a double loop. Here is a 
>> much simpler and faster way to compute this derivative:
>>
>> public class TwrDerivative implements UnivariateRealFunction {
>>
>>   private final double[] a;
>>
>>   public TwrDerivative(double[] pl, double[] b) {
>>     a = new double[pl.length];
>>     for (int i = 0; i < a.length; ++i) {
>>       a[i] = pl[i] / b[i];
>>     }
>>   }
>>
>>   public double value(double f) {
>>     double twr      = 1;
>>     double twrPrime = 0;
>>     for (int i = 0; i < a.length; ++i) {
>>       double factor = 1 + a[i] * f;
>>       twrPrime = twrPrime * factor + twr * a[i];
>>       twr     *= factor;
>>     }
>>     return twrPrime;
>>   }
>>
>> }

By the way, why do you call the gradient result 'prime'?

---------------------------------------------------------------------
To unsubscribe, e-mail: user-unsubscribe@commons.apache.org
For additional commands, e-mail: user-help@commons.apache.org


Mime
View raw message