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== Reference page for I600 exam ==
== Statistics I604 ==
----
Exam help wiki: [https://wiki.itcollege.ee/index.php/Exam_help][https://wiki.itcollege.ee/index.php/User_talk:Lphanvan#Storage_abstractions]
 
== Useful linux commands ==
 
'''Checking information'''
*'''lsb_release -a''' to check OS
*'''uname -sr''' to check OS kernel
*'''cat /proc/cpuinfo''' and check processor information.
*'''arch''' to check CPU architecture
*'''cat /proc/meminfo''' to check memory usage, RAM
*'''lspci -t -v -nn''' to enumerate PCI and PCI Express devices
*'''lsusb and lsusb -t''' to enumerate USB devices
*'''fdisk -l''' to enumerate disks and partitions
*'''lsblk''' to enumerate block devices
*'''xrandr''' to enumerate display outputs
*'''cat /proc/asound/cards''' to check which audio devices are available
*'''dmidecode''' to see even more information about your computer
*'''ifconfig -a or ip addr list''' to list all network interfaces
*'''iwconfig or iw list''' to list all wireless network interfaces
*'''hcitool dev''' to list bluetooth host controller.
*'''glxinfo''' to check 3D rendering capabilities, GPU
*'''lscpu'''  info about cpu and processing units
*'''lshw - short''' info about hardware units, such as cpu, memory, disk, usb controllers, network adapters
*'''hwinfo –short''' info about hardware utility stuff
*'''lspci''' info about pci buses and devices connected to them
*'''lsscsi''' info about sata/scsi devices
*'''lsusb''' info about usb controllers and devices
*'''lsblk''' block information, harddrive partitions
*'''df –H''' info about disk space and partitions that are mounted
*'''fdisk –l'''  info about partitions
*'''free –m''' info about used, free and total amount of RAM
*'''hdparm –i''' info about sata devices
 
 
'''Editing files'''
== Linux Command Line ==
 
ls list files and directories
 
ls -a list all files and directories
 
mkdir make a directory
 
cd directory change to named directory
 
cd change to home-directory
 
cd ~ change to home-directory
 
cd .. change to parent directory
 
pwd display the path of the current directory
 
 
 
'''cp (copy)'''
 
cp file1 file2 is the command which makes a copy of file1 in the current working directory and calls it file2
 
What we are going to do now, is to take a file stored in an open access area of the file system, and use the cp command to copy it to your unixstuff directory.
 
First, cd to your unixstuff directory.
 
% '''cd ~/unixstuff'''
 
Then at the UNIX prompt, type,
 
% '''cp /vol/examples/tutorial/science.txt''' .
 
Note: Don't forget the dot . at the end. Remember, in UNIX, the dot means the current directory.
 
The above command means copy the file science.txt to the current directory, keeping the name the same.
 
(Note: The directory /vol/examples/tutorial/ is an area to which everyone in the school has read and copy access. If you are from outside the University, you can grab a copy of the file here. Use 'File/Save As..' from the menu bar to save it into your unixstuff directory.)
 
Exercise 2a
 
Create a backup of your science.txt file by copying it to a file called science.bak
 
'''2.2 Moving files'''
 
'''mv (move)'''
 
'''mv file1 file2 moves (or renames) file1 to file2'''
 
To move a file from one place to another, use the mv command. This has the effect of moving rather than copying the file, so you end up with only one file rather than two.
 
It can also be used to rename a file, by moving the file to the same directory, but giving it a different name.
 
We are now going to move the file science.bak to your backup directory.
 
First, change directories to your unixstuff directory (can you remember how?). Then, inside the unixstuff directory, type
 
% mv science.bak backups/.
 
Type ls and ls backups to see if it has worked.
 
 
'''2.3 Removing files and directories'''
 
rm (remove), rmdir (remove directory)
 
To delete (remove) a file, use the rm command. As an example, we are going to create a copy of the science.txt file then delete it.
 
Inside your unixstuff directory, type
 
% cp science.txt tempfile.txt
% ls
% rm tempfile.txt
% ls
 
You can use the rmdir command to remove a directory (make sure it is empty first). Try to remove the backups directory. You will not be able to since UNIX will not let you remove a non-empty directory.
 
Exercise 2b
 
Create a directory called tempstuff using mkdir , then remove it using the rmdir command.
 
'''2.4 Displaying the contents of a file on the screen'''
 
clear (clear screen)
 
Before you start the next section, you may like to clear the terminal window of the previous commands so the output of the following commands can be clearly understood.
 
At the prompt, type
 
% clear
 
This will clear all text and leave you with the % prompt at the top of the window.
 
 
'''cat (concatenate)'''
 
The command cat can be used to display the contents of a file on the screen. Type:
 
% cat science.txt
 
As you can see, the file is longer than than the size of the window, so it scrolls past making it unreadable.
 
 
'''less'''
 
The command less writes the contents of a file onto the screen a page at a time. Type
 
% less science.txt
 
Press the [space-bar] if you want to see another page, and type [q] if you want to quit reading. As you can see, less is used in preference to cat for long files.
 
 
'''head'''
 
The head command writes the first ten lines of a file to the screen.
 
First clear the screen then type
 
% head science.txt
 
Then type
 
% head -5 science.txt
 
What difference did the -5 do to the head command?
 
 
'''tail'''
 
The tail command writes the last ten lines of a file to the screen.
 
Clear the screen and type
 
% tail science.txt
 
Q. How can you view the last 15 lines of the file?
 
 
'''2.5 Searching the contents of a file'''
 
Simple searching using less
 
Using less, you can search though a text file for a keyword (pattern). For example, to search through science.txt for the word 'science', type
 
% less science.txt
 
then, still in less, type a forward slash [/] followed by the word to search
 
/science
 
As you can see, less finds and highlights the keyword. Type [n] to search for the next occurrence of the word.
 
 
grep (don't ask why it is called grep)
 
grep is one of many standard UNIX utilities. It searches files for specified words or patterns. First clear the screen, then type
 
% grep science science.txt
 
As you can see, grep has printed out each line containg the word science.
 
Or has it ????
 
Try typing
 
% grep Science science.txt
 
The grep command is case sensitive; it distinguishes between Science and science.
 
To ignore upper/lower case distinctions, use the -i option, i.e. type
 
% grep -i science science.txt
 
To search for a phrase or pattern, you must enclose it in single quotes (the apostrophe symbol). For example to search for spinning top, type
 
% grep -i 'spinning top' science.txt
 
Some of the other options of grep are:
 
-v display those lines that do NOT match
-n precede each matching line with the line number
-c print only the total count of matched lines
Try some of them and see the different results. Don't forget, you can use more than one option at a time. For example, the number of lines without the words science or Science is
 
% grep -ivc science science.txt
 
   
   
Primary Study Materials:
'''Course Homepage:'''  http://www.cs.ioc.ee/ITKStat
'''e-Book:'''          http://onlinestatbook.com/Online_Statistics_Education.pdf


'''wc (word count)'''
Primary Software:
 
'''R:''' https://www.r-project.org/
A handy little utility is the wc command, short for word count. To do a word count on science.txt, type
 
% wc -w science.txt
 
'''To find out how many lines the file has, type'''
 
% wc -l science.txt
 
== NMAP and SSH ==
 
 
'''NMAP'''
*Find my ip: ifconfig
*Scan networks: nmap <ip>
*Find live hosts: nmap -sP 192.168.0.*
*Scan specific port: nmap -p 80 server2.tecmint.com
*Scan a single ip address: nmap 192.168.1.1
*Scan a host name: nmap server1.cyberciti.biz
*Scan a host name with more info : nmap -v server1.cyberciti.biz
*Scan with disabled port scan: nmap -sn 192.168.2.1/24
*Read and scan from txt file: nmap -iL /tmp/test.txt
*Create the txt file to read from: cat > /tmp/test.txt
 
*Shut down a network: <sudo> shutdown -s -m \\192.168.1.1 or '''shutdown -h now'''
 
* nmap --iflist
 
'''SSH'''
*Connect: ssh collie.stanford.edu
*Log-in: ssh jhawkins@collie.stanford.edu
 
== Instruction sets ==
 
nstruction sets may be categorized by the maximum number of operands explicitly specified in instructions.
 
(In the examples that follow, a, b, and c are (direct or calculated) addresses referring to memory cells, while reg1 and so on refer to machine registers.)


C = A+B
== Python I703 ==


  * 0-operand (zero-address machines), so called stack machines: All arithmetic operations take place using the top one or two positions on
    the stack: push a, push b, add, pop c.
    C = A+B needs four instructions. For stack machines, the terms "0-operand" and "zero-address" apply to arithmetic instructions,
    but not to all instructions, as 1-operand push and pop instructions are used to access memory.


    *1-operand (one-address machines), so called accumulator machines, include early computers and many small microcontrollers: most instructions
    Get an idea what to do by next week. Ideas:
    specify a single right operand (that is, constant, a register, or a memory location), with the implicit accumulator as the left operand
    '''1. Pyglet,pygame or kivy for a game or simulation:'''
    (and the destination if there is one): load a, add b, store c.
    1.1. MP beat em' up
    C = A+B needs three instructions.
    1.2. Survival space sim, use webcam for dynamic view
    1.3. Planet rotation simulation
    '''Check out '''
    http://nehe.gamedev.net/
    http://learnpythonthehardway.org/


    *2-operand — many CISC and RISC machines fall under this category:
    '''2. WebApp'''
        CISC — move A to C; then add B to C.
    2.1. Budget Management with a GUI
            C = A+B needs two instructions. This effectively 'stores' the result without an explicit store instruction.
            CISC — Often machines are limited to one memory operand per instruction: load a,reg1; add b,reg1; store reg1,c;
            This requires a load/store pair for any memory movement regardless of whether the add result is an augmentation
            stored to a different place, as in C = A+B, or the same memory location: A = A+B.
            C = A+B needs three instructions.
            RISC — Requiring explicit memory loads, the instructions would be: load a,reg1; load b,reg2; add reg1,reg2; store reg2,c.
            C = A+B needs four instructions.


     *3-operand, allowing better reuse of data:[5]
    '''Notes:'''
        CISC — It becomes either a single instruction: add a,b,c
     * Set up RPi web-server
            C = A+B needs one instruction.
    * Use '''XMind''' to map the idea first
            or more typically: move a,reg1; add reg1,b,c as most machines are limited to two memory operands.
    * Run basic website and deploy webapp to it.  
                C = A+B needs two instructions.
    * Check out RPi components and sensors.  
        RISC — arithmetic instructions use registers only, so explicit 2-operand load/store instructions are needed:
    * Buy a breadboard.
        load a,reg1; load b,reg2; add reg1+reg2->reg3; store reg3,c;
    * Check out Notepad++
            C = A+B needs four instructions.
            Unlike 2-operand or 1-operand, this leaves all three values a, b, and c in registers available for further reuse.[5]


== Web Application Programming I702 ==
   
   
    LDA - Loads the contents of the memory address or integer into the accumulator
  '''node.js'''
    ADD - Adds the contents of the memory address or integer to the accumulator
  '''ngix'''
    STO - Stores the contents of the accumulator into the addressed location
  '''nchan'''
 
 
  ADD ;add one number to another number
  SUB ;subtract one number to another number
  INC ;increment a number by 1
  DEC ;decrement a number by 1
  MUL ;multiply numbers together
  OR  ;boolean algebra function
  AND ;boolean algebra function
  NOT ;boolean algebra function
  XOR ;boolean algebra function
  JNZ ;jump to another section of code if a number is not zero (used for loops and ifs)
  JZ  ;jump to another section of code if a number is zero (used for loops and ifs)
  JMP ;jump to another section of code (used for loops and ifs)
 
  1 LDA #12 ;loads the number 12 into the accumulator
  2 MUL #2  ;multiplies the accumulator by 2 = 24
  3 SUB #6  ;take 6 away from the accumulator = 18
  4 JNZ 6  ;if the accumulator <> 0 then goto line 6
  5 SUB #5 ;take 5 away from the accumulator (this line isn't executed!)
  6 STO 34  ;saves the accumulator result (18) to the memory address 34
 
Addressing Mode Symbol Example Description
Memory Location LOAD 15 15 is treated as an address
Integer         # LOAD #15 15 is treated as a number
Nothing         HALT         Some inst. dont need operands
 
== Truth Tables ==
 
'''Logical Conjunction(AND)'''
p q p ∧ q
T T        T
T F   F
F T   F
F F   F
 
  '''Logical Disjunction(OR)'''
p q p ∨ q
T T   T
T F   T
F T   T
F F   F
 
  '''Logical NAND'''
p q p ↑ q
T T   F
T F   T
F T   T
F F   T
 
'''Logical  NOR'''
p q p ↓ q
T T   F
T F   F
F T   F
F F   T
 
== Compression ==


Data compression ratio is defined as the ratio between the uncompressed size and compressed size:
'''Useful links:'''
  http://enos.itcollege.ee/phpmyadmin/
  http://enos.itcollege.ee/~ksaareme


    Compression Ratio = Uncompressed Size / Compressed Size
'''W3C validation:''' https://validator.w3.org/


Thus a representation that compresses a 10MB file to 2MB has a compression ratio of 10/2 = 5, often notated as an explicit ratio, 5:1 (read "five" to "one"), or as an implicit ratio, 5/1. Note that this formulation applies equally for compression, where the uncompressed size is that of the original; and for decompression, where the uncompressed size is that of the reproduction.
== Node.js ==


Sometimes the space savings is given instead, which is defined as the reduction in size relative to the uncompressed size:
Stuff about node.js.


  Space Savings = 1 - Compressed Size / Uncompressed Size
== Operating Systems ==
Thus a representation that compresses a 10MB file to 2MB would yield a space savings of 1 - 2/10 = 0.8, often notated as a percentage, 80%.


For signals of indefinite size, such as streaming audio and video, the compression ratio is defined in terms of uncompressed and compressed data rates instead of data sizes:
Command line:


    Compression Ratio = Uncompressed Data Rate/ Compressed Data Rate
    '''Options modify the behavior of commands:'''
        ls -a lists all contents of a directory, including hidden files and directories
        ls -l lists all contents in long format
        ls -t orders files and directories by the time they were last modified
        Multiple options can be used together, like ls -alt
    '''From the command line, you can also copy, move, and remove files and directories:'''
        cp copies files
        mv moves and renames files
        rm removes files
        rm -r removes directories
    '''Wildcards are useful for selecting groups of files and directories'''


and instead of space savings, one speaks of data-rate savings, which is defined as the data-rate reduction relative to the uncompressed data rate:


  Data Rate Savings = 1 - Compressed Data Rate / Uncompressed Data Rate
For example, uncompressed songs in CD format have a data rate of 16 bits/channel x 2 channels x 44.1 kHz ≅ 1.4 Mbit/s, whereas AAC files on an iPod are typically compressed to 128 kbit/s, yielding a compression ratio of 10.9, for a data-rate savings of 0.91, or 91%.


When the uncompressed data rate is known, the compression ratio can be inferred from the compressed data rate.
    '''Redirection reroutes standard input, standard output, and standard error.'''


== Bits and Bytes ==
    '''The common redirection commands are:'''
        > redirects standard output of a command to a file, overwriting previous content.
        >> redirects standard output of a command to a file, appending new content to old content.
        < redirects standard input to a command.
        | redirects standard output of a command to another command.


File Storage Capacity by Bits and Bytes
    '''A number of other commands are powerful when combined with redirection commands:'''
  bit byte kibibyte mebibyte gibibyte
        sort: sorts lines of text alphabetically.
bit 1 0.125 0.000122070312 1.192092895×10-7 1.16415321875×10-10
        uniq: filters duplicate, adjacent lines of text.
byte 8 1 0.0009765625 9.53674316×10-7 9.31322575×10-10
        grep: searches for a text pattern and outputs it.
kibibyte 8 192 1 024 1 0.0009765625 9.53674316×10-7
        sed : searches for a text pattern, modifies it, and outputs it.
mebibyte 8 388 608 1 048 576 1 024 1 0.0009765625
gibibyte 8 589 934 592 1 073 741 824 1 048 576 1 024 1
tebibyte 8 796 093 022 208 1 099 511 627 776 1 073 741 824 1 048 576 1 024
pebibyte 9 007 199 254 740 990 1 125 899 906 842 624 1 099 511 627 776 1 073 741 824 1 048 576
exbibyte 9 223 372 036 854 780 000 1 152 921 504 606 846 976 1 125 899 906 842 624 1 099 511 627 776 1 073 741 824
zebibyte 9 444 732 965 739 290 000 000 1 180 591 620 717 411 303 424 1 152 921 504 606 846 976 1 125 899 906 842 624 1 099 511 627 776

Latest revision as of 13:57, 6 February 2016

Statistics I604

Primary Study Materials:
Course Homepage:  http://www.cs.ioc.ee/ITKStat
e-Book:           http://onlinestatbook.com/Online_Statistics_Education.pdf

Primary Software:
R: https://www.r-project.org/

Python I703

    Get an idea what to do by next week. Ideas:
    1. Pyglet,pygame or kivy for a game or simulation:
    1.1. MP beat em' up
    1.2. Survival space sim, use webcam for dynamic view
    1.3. Planet rotation simulation
    Check out 
    http://nehe.gamedev.net/
    http://learnpythonthehardway.org/

    2. WebApp
    2.1. Budget Management with a GUI

   Notes: 
   * Set up RPi web-server
   * Use XMind to map the idea first
   * Run basic website and deploy webapp to it. 
   * Check out RPi components and sensors. 
   * Buy a breadboard.
   * Check out Notepad++

Web Application Programming I702

node.js
ngix
nchan

Useful links:
  http://enos.itcollege.ee/phpmyadmin/
  http://enos.itcollege.ee/~ksaareme

W3C validation: https://validator.w3.org/

Node.js

Stuff about node.js.

Operating Systems

Command line: 

   Options modify the behavior of commands:
       ls -a lists all contents of a directory, including hidden files and directories
       ls -l lists all contents in long format
       ls -t orders files and directories by the time they were last modified
       Multiple options can be used together, like ls -alt
   From the command line, you can also copy, move, and remove files and directories:
       cp copies files
       mv moves and renames files
       rm removes files
       rm -r removes directories
   Wildcards are useful for selecting groups of files and directories



   Redirection reroutes standard input, standard output, and standard error.

   The common redirection commands are:
       > redirects standard output of a command to a file, overwriting previous content.
       >> redirects standard output of a command to a file, appending new content to old content.
       < redirects standard input to a command.
       | redirects standard output of a command to another command.

   A number of other commands are powerful when combined with redirection commands:
       sort: sorts lines of text alphabetically.
       uniq: filters duplicate, adjacent lines of text.
       grep: searches for a text pattern and outputs it.
       sed : searches for a text pattern, modifies it, and outputs it.
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