general computer science for engineers cisc 106 lecture 02

General Computer Science General Computer Science for Engineersfor Engineers

CISC 106CISC 106Lecture 02Lecture 02

James AtlasComputer and Information Sciences

CPU

Disk

Memory

How does our program work?

1. ~~~~~~~~~~2. ~~~~~~~~~~3. ~~~~~~~~~~4. ~~~~~~~~~~5. ~~~~~~~~~~6. ~~~~~~~~~~7. ~~~~~~~~~~8. ~~~~~~~~~~

. . .

x86 instructions

Our Program in Memory

VariablesVariablesvar = expression

x = 2 * 2comment = ‘This is a string’area = circleArea(5)

What type of data is stored in each variable?

How do computers store data?Binary

◦Billions of tiny logic gates representing ON and OFF (1 and 0)

Video◦ http://www.youtube.com/watch?

v=b6vHZ95XDwU

Data Types in MatlabFloating point number by default

◦“double” precision = 64-bits of memory

Operations on Data Types5.5single(5.5)int8(5)int8(500) ?int8(‘c’) ?char(98) ?

>> x = 5.5>> whos x

ExpressionsData and Operator

◦2 + 2◦circleArea(5)

ExpressionsData and Operator

◦2 + 2◦circleArea(5)

Nested Expressions◦circleArea(circleArea(5 + 2) +

circleArea(3))

ExpressionsData and Operator

◦2 + 2◦circleArea(5)

Nested Expressions◦circleArea(circleArea(5 + 2) +

circleArea(3))

Expressions produce a value

Lab00 (pre-lab) / Lab01

Using Matlab Remotely (text)ssh yourusername@strauss.udel.edu

◦requires an ssh program such as PuTTY◦see course website for installation details

at prompt type:matlab -nodesktop

Using Matlab Remotely (GUI)Mac users:

◦ You already have an X-Windows environmentPC users:

◦ You must setup Cygwin-X◦ Download Cygwin setup.exe from:

http://www.cygwin.com/◦ Run setup.exe and select additional packages

for: xauth xinit openssh

Running Matlab RemotelyOnce the X-Windows environment is

setup, open a terminal window and login to strauss:◦ssh -YC yourusername@strauss.udel.edu

Now start Matlab:◦matlab &

What does the & do?