SE250:lab-5:srag014

This lab is asscociated with hash functions and hash tables. I am so lost with this lab, so very confused with this! I got some help from my some people before I knew what I was doing (still am a bit unsure LOL). After reading the lab sheet and downloading all the files required, I chose these values:

int sample_size = 1000;
int n_keys = 1000;
int table_size = 1000;

It asked me to choose a sensibile number and I chose 1000 becuase its not too big of a number or too small of a number.

Testing Buzhash

• Low

Entropy = 7.843786 bits per byte.

Optimum compression would reduce the size
of this 1000 byte file by 1 percent.

Chi square distribution for 1000 samples is 214.46, and randomly
would exceed this value 95.00 percent of the times.

Arithmetic mean value of data bytes is 128.0860 (127.5 = random).
Monte Carlo value for Pi is 3.132530120 (error 0.29 percent).
Serial correlation coefficient is -0.017268 (totally uncorrelated = 0.0).


Buzhash low 1000/1000: llps = 6, expecting 5.51384

Testing Buzhashn

• Low

Entropy = 7.823873 bits per byte.

Optimum compression would reduce the size
of this 1000 byte file by 2 percent.

Chi square distribution for 1000 samples is 220.61, and randomly
would exceed this value 90.00 percent of the times.

Arithmetic mean value of data bytes is 127.3730 (127.5 = random).
Monte Carlo value for Pi is 3.108433735 (error 1.06 percent).
Serial correlation coefficient is -0.007118 (totally uncorrelated = 0.0).


Buzhashn 1000/1000: llps = 5, expecting 5.51384

Testing Hash_CRC

• Low

Entropy = 3.965965 bits per byte.

Optimum compression would reduce the size
of this 1000 byte file by 50 percent.

Chi square distribution for 1000 samples is 36163.52, and randomly
would exceed this value 0.01 percent of the times.

Arithmetic mean value of data bytes is 93.6860 (127.5 = random).
Monte Carlo value for Pi is 4.000000000 (error 27.32 percent).
Serial correlation coefficient is -0.380754 (totally uncorrelated = 0.0).


Hash CRC low 1000/1000: llps = 11, expecting 5.51384

Testing Base256

• Low

Entropy = 0.000000 bits per byte.

Optimum compression would reduce the size
of this 1000 byte file by 100 percent.

Chi square distribution for 1000 samples is 255000.00, 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!).


Base256 low 1000/1000: llps = 1000, expecting 5.51384

Testing Java Integer

• Low

Entropy = 2.791730 bits per byte.

Optimum compression would reduce the size
of this 1000 byte file by 65 percent. 

Chi square distribution for 1000 samples is 143448.00, and randomly
would exceed this value 0.01 percent of the times.

Arithmetic mean value of data bytes is 31.1250 (127.5 = random).
Monte Carlo value for Pi is 4.000000000 (error 27.32 percent).
Serial correlation coefficient is -0.230200 (totally uncorrelated = 0.0).


Java Integer 1000/1000: llps = 1, expecting 5.51384

Testing Java Object

• Low

Entropy = 2.000000 bits per byte.

Optimum compression would reduce the size
of this 1000 byte file by 75 percent.

Chi square distribution for 1000 samples is 63000.00, and randomly
would exceed this value 0.01 percent of the times.

Arithmetic mean value of data bytes is 95.5000 (127.5 = random).
Monte Carlo value for Pi is 4.000000000 (error 27.32 percent).
Serial correlation coefficient is -0.037404 (totally uncorrelated = 0.0).


Java Object low 1000/1000: llps = 1000, expecting 5.51384

Testing Java String

• Low

Entropy = 7.916396 bits per byte.

Optimum compression would reduce the size
of this 1000 byte file by 1 percent.

Chi square distribution for 1000 samples is 111.55, and randomly
would exceed this value 99.99 percent of the times.

Arithmetic mean value of data bytes is 129.4710 (127.5 = random).
Monte Carlo value for Pi is 3.156626506 (error 0.48 percent).
Serial correlation coefficient is 0.009052 (totally uncorrelated = 0.0).
 

Java String low 1000/1000: llps = 4, expecting 5.51384

Testing Random

• Low

Entropy = 4.643488 bits per byte.

Optimum compression would reduce the size
of this 1000 byte file by 41 percent.

Chi square distribution for 1000 samples is 64480.70, and randomly
would exceed this value 0.01 percent of the times.

Arithmetic mean value of data bytes is 46.9660 (127.5 = random).
Monte Carlo value for Pi is 4.000000000 (error 27.32 percent).
Serial correlation coefficient is -0.043108 (totally uncorrelated = 0.0).

Testing High Random

• Low

Entropy = 0.000000 bits per byte.

Optimum compression would reduce the size
of this 1000 byte file by 100 percent.

Chi square distribution for 1000 samples is 255000.00, and randomly
would exceed this value 0.01 percent of the times.

Arithmetic mean value of data bytes is 0.0000 (127.5 = random).
Monte Carlo value for Pi is 4.000000000 (error 27.32 percent).
Serial correlation coefficient is undefined (all values equal!).

After doing this I commented out the #define VERBOSE_OUTPUT line and got the results in a table format:

Buzhash low             7.84379 95.00%  128.086 0.29%   -0.017268
Buzhashn low            7.82387 90.00%  127.373 1.06%   -0.007118
Hash CRC low            4.04588 0.01%   94.848  27.32%  -0.395249
Base256 low             0.00000 0.01%   97.000  27.32%  undefined
Java Integer low        2.79173 0.01%   31.125  27.32%  -0.230200
Java Object low         2.00000 0.01%   95.500  27.32%  -0.037404
Java String low         7.91760 99.99%  126.441 1.25%   0.003240
Random low              4.64349 0.01%   46.966  27.32%  -0.043108
High Random low         0.00000 0.01%   0.000   27.32%  undefined