Changes between Version 10 and Version 11 of CreditNew

Timestamp:

Nov 4, 2009, 3:47:43 PM (15 years ago)

Author:

davea

Comment:

--

CreditNew

@@ -28 +28 @@
 
  * Project neutrality: different projects should grant
-   about the same amount of credit per day for a given host.
+   about the same amount of credit per day for a given processor.
 
 It's easy to show that both goals can't be satisfied simultaneously.
@@ -241 +241 @@
  * A given sample may be wildly off,
    and we can't let this mess up the average.
+ * Averages should be weighted by job size.
 
 In addition, we may as well maintain the variance of the quantities,
 although the current system doesn't use it.
 
-So for each quantity we maintain the following object:
-{{{
-#define MIN_SAMPLES    20
-    // after this many samples, use exponentially averaged version
-#define SAMPLE_WEIGHT    0.001
-    // new samples get this weight in exp avg
-#define SAMPLE_LIMIT    10
-    // cap samples at recent_mean*10
-
-struct STATS {
-    int nsamples;
-    double mean;
-    double sum_var;
-    double recent_mean;
-    double recent_var;
-
-    void update(double sample) {
-        if (sample < 0) return;
-        if (nsamples > MIN_SAMPLES) {
-            if (sample > recent_mean*SAMPLE_LIMIT) {
-                sample = recent_main*SAMPLE_LIMIT;
-            }
-        }
-        // see http://en.wikipedia.org/wiki/Algorithms_for_calculating_variance
-        nsamples++;
-        double delta = sample - mean;
-        mean += delta/nsamples;
-        sum_var += delta*(sample-mean);
-
-        if (nsamples < MIN_SAMPLES) {
-            recent_mean = mean;
-            recent_var = sum_var/nsamples;
-        } else {
-            // update recent averages
-            delta = sample - recent_mean;
-            recent_mean += SAMPLE_WEIGHT*delta;
-            double d2 = delta*delta - recent_var;
-            recent_var += SAMPLE_WEIGHT*d2;
-        }
-    }
-};
-}}}
+The code that does all this is
+[http://boinc.berkeley.edu/trac/browser/trunk/boinc/lib/average.h here].
 
 == Cross-project scaling factors ==