source: liacs/os/assignment7/README@ 422

Student: Rick van der Zwet - 0433373

> Question 1: Estimate the space to store 10^10 float numbers, using the
> following cases, take in count to minimize the storage costs, while
> preserving the full number accuracy.

I take a float to be single precision (called float in C language) as
the definition of float. This occupied 32 bits (4 bytes), and has got
a significand precision of 24 bits (7 decimal digits)
source: http://en.wikipedia.org/wiki/IEEE_754-1985
To store integers of max 10^10, there is a need of a 64 bit integer
(also called long)
source: http://en.wikipedia.org/wiki/Integer_%28computer_science%29

> a)  We store the float numbers together with their integer index as
>     characters in a flat CSV file.

Each line will look like: <index>,<float><newline>. The max numbers
of characters of <index> will be 11, <float> will take up 7 and 1 extra
as delimiter. Extra on every line will be 2, due to the delimiters. So 1
line will contain 11 + 8 + 2 = 21 characters. In total 10^10 * 21. If
you choose to use the line number as index number you will only need 8
+1 * 10^10 characters, which is roughly (1 char = 4 bytes) 36 * 10^10

> b)  We store the numbers together with their index in a MySQL database.
>     Make your choice between FLOAT, DOUBLE types for the numbers and
>     SIGNED/UNSIGNED TINYINT indeces.

UNSIGNED is the best choice as we are not dealing with negative
numbers, the index is by default set in a mysql table as it it used to
refer to the data. A FLOAT takes up 4 bytes a DOUBLE 8 bytes. So roughly
in total it takes up (8 + 1) * 10^10 bytes. You could enlarge your FLOAT
to gain more persision, or make it general to make sure you will only
start loose presition after 53 digits.
source: http://dev.mysql.com/doc/refman/5.0/en/numeric-types.html
source: http://dev.mysql.com/doc/refman/5.0/en/storage-requirements.html

> c)  We store the numbers in a binary format of your own together with
>     indeces.

After storing all numbers in just the simplest format as posible,
float numbers next after eachother with a delimiter in between,would
make it most effient. 


> Question 2: Giving the following cases, make some rough estimations the
> time necessary to compute 10^10 association tests. 

Results in days,years are rounded.
Case    |   each test in sec  | Total/sec | Total/days | Total/years
--------|---------------------|-----------|------------|------------
a)      |   1                 | 10^10     | 115.740    | 317
b)      |   0.1               | 10^9      |  11.574    | 32
c)      |   0.01              | 10^8      |   1.157    | 3
d)      |   0.001             | 10^7      |     116    | 0

> Question 3: Create a user-space envirionment for the free scientific
> computation envirionment R.

The shell script attached will create the envirionment. Commented parts
shows what's currently going on. I have had a create help of the
README.txt and INSTALL.txt which came with the software packages