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2008-11-03T05:19:53Z

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= Lab 5 =
To begin with, I must confess, this lab does not make any sense to me as of yet. Apart from the fact that we are using a number of different tests (which i know nothing about, and only consider them as a black box) to measure how effective each of the different types of hash functions are.

== Task 1 ==
After a little bit of prior preperation, i've selected these numbers.

int sample_size = 1000;
int n_keys = 250000;
int table_size = 400000;

=== Low Entropy Results ===

==== Buzhash ====
Testing Buzhash low on 500 samples
Entropy = 7.606529 bits per byte.

Optimum compression would reduce the size
of this 500 byte file by 4 percent.

Chi square distribution for 500 samples is 255.71, and randomly
would exceed this value 50.00 percent of the times.

Arithmetic mean value of data bytes is 131.8860 (127.5 = random).
Monte Carlo value for Pi is 3.036144578 (error 3.36 percent).
Serial correlation coefficient is -0.033469 (totally uncorrelated = 0.0).

==== Buzhashn ====
Testing Buzhashn low on 500 samples
Entropy = 7.684438 bits per byte.

Optimum compression would reduce the size
of this 500 byte file by 3 percent.

Chi square distribution for 500 samples is 178.91, and randomly
would exceed this value 99.95 percent of the times.

Arithmetic mean value of data bytes is 125.4580 (127.5 = random).
Monte Carlo value for Pi is 3.180722892 (error 1.25 percent).
Serial correlation coefficient is 0.025355 (totally uncorrelated = 0.0).

==== Hash_CRC ====
Testing Hash_CRC low on 500 samples
Entropy = 3.741407 bits per byte.

Optimum compression would reduce the size
of this 500 byte file by 53 percent.

Chi square distribution for 500 samples is 18208.48, and randomly
would exceed this value 0.01 percent of the times.

Arithmetic mean value of data bytes is 92.9200 (127.5 = random).
Monte Carlo value for Pi is 4.000000000 (error 27.32 percent).
Serial correlation coefficient is -0.372104 (totally uncorrelated = 0.0).

==== Base 256 ====
Testing Base256 low on 500 samples
Entropy = 0.000000 bits per byte.

Optimum compression would reduce the size
of this 500 byte file by 100 percent.

Chi square distribution for 500 samples is 127500.00, and randomly
would exceed this value 0.01 percent of the times.

Arithmetic mean value of data bytes is 97.0000 (127.5 = random).
Monte Carlo value for Pi is 4.000000000 (error 27.32 percent).
Serial correlation coefficient is undefined (all values equal!).

==== Java_Integer ====
Testing Java_Integer low on 500 samples
Entropy = 2.532733 bits per byte.

Optimum compression would reduce the size
of this 500 byte file by 68 percent.

Chi square distribution for 500 samples is 71948.00, and randomly
would exceed this value 0.01 percent of the times.

Arithmetic mean value of data bytes is 15.5000 (127.5 = random).
Monte Carlo value for Pi is 4.000000000 (error 27.32 percent).
Serial correlation coefficient is -0.229630 (totally uncorrelated = 0.0).

==== Java_Object ====
Testing Java_Object low on 500 samples
Entropy = 2.000000 bits per byte.

Optimum compression would reduce the size
of this 500 byte file by 75 percent.

Chi square distribution for 500 samples is 31500.00, and randomly
would exceed this value 0.01 percent of the times.

Arithmetic mean value of data bytes is 77.0000 (127.5 = random).
Monte Carlo value for Pi is 4.000000000 (error 27.32 percent).
Serial correlation coefficient is -0.521556 (totally uncorrelated = 0.0).

==== Java_String ====
Testing Java_String low on 500 samples
Entropy = 7.737340 bits per byte.

Optimum compression would reduce the size
of this 500 byte file by 3 percent.

Chi square distribution for 500 samples is 153.31, and randomly
would exceed this value 99.99 percent of the times.

Arithmetic mean value of data bytes is 128.4260 (127.5 = random).
Monte Carlo value for Pi is 3.277108434 (error 4.31 percent).
Serial correlation coefficient is -0.068098 (totally uncorrelated = 0.0).

==== Rand ====
Testing Rand low on 500 samples
Entropy = 7.530516 bits per byte.

Optimum compression would reduce the size
of this 500 byte file by 5 percent.

Chi square distribution for 500 samples is 305.89, and randomly
would exceed this value 2.50 percent of the times.

Arithmetic mean value of data bytes is 107.6640 (127.5 = random).
Monte Carlo value for Pi is 3.566265060 (error 13.52 percent).
Serial correlation coefficient is -0.034205 (totally uncorrelated = 0.0).

==== High_rand ====
Testing High_rand low on 500 samples
Entropy = 7.568083 bits per byte.

Optimum compression would reduce the size
of this 500 byte file by 5 percent.

Chi square distribution for 500 samples is 265.95, and randomly
would exceed this value 50.00 percent of the times.

Arithmetic mean value of data bytes is 132.7680 (127.5 = random).
Monte Carlo value for Pi is 2.554216867 (error 18.70 percent).
Serial correlation coefficient is 0.057176 (totally uncorrelated = 0.0).

=== Typical Entropy results ===

==== Buzhash ====
Testing Buzhash typical on 500 samples
Entropy = 7.529310 bits per byte.

Optimum compression would reduce the size
of this 500 byte file by 5 percent.

Chi square distribution for 500 samples is 287.46, and randomly
would exceed this value 10.00 percent of the times.

Arithmetic mean value of data bytes is 125.7860 (127.5 = random).
Monte Carlo value for Pi is 3.325301205 (error 5.85 percent).
Serial correlation coefficient is 0.006752 (totally uncorrelated = 0.0).

==== Buzhashn ====
Testing Buzhashn typical on 500 samples
Entropy = 7.684438 bits per byte.

Optimum compression would reduce the size
of this 500 byte file by 3 percent.

Chi square distribution for 500 samples is 178.91, and randomly
would exceed this value 99.95 percent of the times.

Arithmetic mean value of data bytes is 125.4580 (127.5 = random).
Monte Carlo value for Pi is 3.180722892 (error 1.25 percent).
Serial correlation coefficient is 0.025355 (totally uncorrelated = 0.0).

==== Hash_CRC ====

Testing Hash_CRC typical on 500 samples
Entropy = 6.769234 bits per byte.

Optimum compression would reduce the size
of this 500 byte file by 15 percent.

Chi square distribution for 500 samples is 1261.28, and randomly
would exceed this value 0.01 percent of the times.

Arithmetic mean value of data bytes is 104.4000 (127.5 = random).
Monte Carlo value for Pi is 3.373493976 (error 7.38 percent).
Serial correlation coefficient is -0.034608 (totally uncorrelated = 0.0).

==== Base 256 ====

Testing Base256 typical on 500 samples
Entropy = 3.929009 bits per byte.

Optimum compression would reduce the size
of this 500 byte file by 50 percent.

Chi square distribution for 500 samples is 10130.14, and randomly
would exceed this value 0.01 percent of the times.

Arithmetic mean value of data bytes is 104.8520 (127.5 = random).
Monte Carlo value for Pi is 4.000000000 (error 27.32 percent).
Serial correlation coefficient is 0.263097 (totally uncorrelated = 0.0).

==== Java_Integer ====
Testing Java_Integer typical on 500 samples
Entropy = 2.532733 bits per byte.

Optimum compression would reduce the size
of this 500 byte file by 68 percent.

Chi square distribution for 500 samples is 71948.00, and randomly
would exceed this value 0.01 percent of the times.

Arithmetic mean value of data bytes is 15.5000 (127.5 = random).
Monte Carlo value for Pi is 4.000000000 (error 27.32 percent).
Serial correlation coefficient is -0.229630 (totally uncorrelated = 0.0).

==== Java_Object ====
Testing Java_Object typical on 500 samples
Entropy = 4.045873 bits per byte.

Optimum compression would reduce the size
of this 500 byte file by 49 percent.

Chi square distribution for 500 samples is 16446.18, and randomly
would exceed this value 0.01 percent of the times.

Arithmetic mean value of data bytes is 87.9180 (127.5 = random).
Monte Carlo value for Pi is 4.000000000 (error 27.32 percent).
Serial correlation coefficient is -0.744332 (totally uncorrelated = 0.0).

==== Java_String ====
Testing Java_String typical on 500 samples
Entropy = 6.940142 bits per byte.

Optimum compression would reduce the size
of this 500 byte file by 13 percent.

Chi square distribution for 500 samples is 1177.31, and randomly
would exceed this value 0.01 percent of the times.

Arithmetic mean value of data bytes is 113.3500 (127.5 = random).
Monte Carlo value for Pi is 3.421686747 (error 8.92 percent).
Serial correlation coefficient is -0.018572 (totally uncorrelated = 0.0).

==== Rand ====
Testing Rand typical on 500 samples
Entropy = 7.530516 bits per byte.

Optimum compression would reduce the size
of this 500 byte file by 5 percent.

Chi square distribution for 500 samples is 305.89, and randomly
would exceed this value 2.50 percent of the times.

Arithmetic mean value of data bytes is 107.6640 (127.5 = random).
Monte Carlo value for Pi is 3.566265060 (error 13.52 percent).
Serial correlation coefficient is -0.034205 (totally uncorrelated = 0.0).

==== High_rand ====
Testing High_rand typical on 500 samples
Entropy = 7.568083 bits per byte.

Optimum compression would reduce the size
of this 500 byte file by 5 percent.

Chi square distribution for 500 samples is 265.95, and randomly
would exceed this value 50.00 percent of the times.

Arithmetic mean value of data bytes is 132.7680 (127.5 = random).
Monte Carlo value for Pi is 2.554216867 (error 18.70 percent).
Serial correlation coefficient is 0.057176 (totally uncorrelated = 0.0).

SE250:lab-5:rbha033 - Revision history

Mark: 9 revision(s)