CS107: Computing for Math and ScienceCS107, Prof. Steinberg, f10 Lecture 01 6 What is CS107? •A...

CS107, Prof. Steinberg, f10 1Lecture 01

CS107: Computing for MathCS107: Computing for Mathand Scienceand Science

• Instructor: Prof. Louis Steinberg– office: Hill 401– email: [email protected]– Office hours: by appointment

• TAs:– Andre Cohen acohen @ cs.rutgers.edu– Xiaoye xiaoye @ cs.rutgers.edu



• Instructor: Prof. Apostolos Gerasoulis– office: Core 328– email: [email protected]– Office hours: by appointment

• TA:– Nader Boushehrinejadmoradi

[email protected]



• Course will use the computer forcommunication and instruction as muchas possible


Class Web PagesClass Web Pages•• http://http://remusremus..rutgersrutgers..eduedu/CS107/CS107

– Policies– Syllabus– Assignments– Lecture notes– etc....

– You are assumed to know anythingposted.


Class Web PagesClass Web Pages•• Sakai: Sakai: cscs 107, Fall 2010 107, Fall 2010

– Announcements– Posting grades– Chat room– Etc.

– You are assumed to know anythingposted.


What is CS107?What is CS107?• A course about using computers• Aimed at majors in Math and Science• After this class you should know• Methods for using the computer that will be useful

for mathematicians & scientists• Some key ideas in computer science

• CS 107 does not prepare you to take furthercourses in the CS Dept.


PrerequisitePrerequisite• Calc I– 640:135 or 151 or 153 or 191– Grade of C or better

• No previous programming experience isassumed

• We will assume you do know how to use amouse, web browser, etc.


Should you take CS107?Should you take CS107?• Math or science major, had calc I: YES• Exceptions:– Computer Science major or minor: NO

– Except: unsure about CS: MAYBE– Option B: The Computer-Oriented

Mathematics Major: NO


Grade based onGrade based on• Homework• Midterm exam• In-lecture quizzes• Final exam


TextbooksTextbooksIntroduction to Scientific

Computation andProgrammingDaniel T KaplanBrooks/Cole

The Maple BookFrank GarmanChapman & Hall/CRC


What is a computer?What is a computer?


What is a computer?What is a computer?• A machine that follows instructions• Note the anthropomorphism here


Anthropomorphism:Anthropomorphism:Use of a term normally applied to

people when speaking of something that isnot a person

• An analogy• Useful but dangerous

– What is the same– What is different


How can a machine followHow can a machine followinstructions?instructions?

• Example: Washing machine controller– Controls hot water, cold water, drain, motor


Hot Wash, Warm RinseHot Wash, Warm Rinse

C MDH Peg

No Peg


Washing Machine InstructionsWashing Machine Instructions• A pattern of physical objects (pegs)– Physically causes the specified behavior


ComputerComputer Instructions Instructions• A pattern of electrical voltages

– Physically causes the specified behavior

5 voltsRandom Access Memory

0 volts


• People can read, write, think about thepattern without really having thepegs

• Patterns can be thought of as a languagefor expressing washing machineinstructions

Washing Machine LanguageWashing Machine Language


Anthropomorphism AlertAnthropomorphism Alert• How is washing machine language like a

human (“natural”) language?• How is it different?


• People can read, write, think about thepattern without really having thevoltages

• Patterns can be thought of as a languagefor expressing computerinstructions

ComputerComputer Machine Language Machine Language


Washing Machine LanguagesWashing Machine Languages• Each washing machine operation does a

very small amount of work• People would find it tedious and error

prone to instruct their washers inthis language

• So, we have a higher level language– Warm wash, cold rinse


ComputerComputer Languages Languages• Each computer operation does a

very small amount of work• People would find it tedious and error

prone to instruct their computers inthis language

• So, we have a higher level language– Matlab– Java, Basic, Fortran, C, Lisp, ...


Washing Machine LanguagesWashing Machine Languages• There is a fixed set of primitive operations– Hot, Cold, Drain, Motor

• And a way of combining operations– Rows obeyed in sequence

• We have to build behavior we want out ofthe primitives available– Hot + Cold => Warm


ComputerComputer Languages Languages• There is a fixed set of primitive operations

• And a way of combining operations

• We have to build behavior we want out ofthe primitives available


Is a Washing Machine aIs a Washing Machine aComputer?Computer?

• A computer is a machine thatfollows instructionsand processes data


DataData• Numbers, words, pictures, …• Data processing– What Kaplan text calls “computation”– Any process that transforms some data into

other data, e.g. addition


RepresentationRepresentation• In a computer, data embodied as charge

or voltage– E.g.: 0 volts means 0, 5 volts means 1– A “bit”: a 2-way choice, e.g. 0 volts vs 5 volts

• Data is represented by groups of bits– E.g.: 3 bits gives 8 patterns: 000 001 010 011 100 101 110 111


TranslationTranslation• Problem: pegs & switches understand

only machine language• How can we get instructions in higher

level language obeyed?• Translation:– “warm wash, cold rinse” dial selects a set of

pegs


TranslationTranslation• Problem: transistors understand only

machine language• How can we get instructions in higher

level language obeyed?• Translation:– Instructions are also data– A program does the translation


GrammarGrammar• To make it easier to translate, a program

must have a structure that obeys agrammar– simple but rigid rules


A ProgramA Programis more like a mechanism you buildthan a sentence you say.


Kinds of KnowledgeKinds of Knowledge• Knowing that– Knowing a fact, e.g. rules of Chess

• Knowing how– Knowing how to use facts to achieve a goal,

e.g. how to win at chess


E.G., AlgebraE.G., Algebra• Knowing that

If X = Y then X + a = Y + a• Knowing how– To solve 3*x - 5 = 10, start by adding 5 to

both sides of the equation3*x - 5 + 5 = 10 + 53*x = 15


To Construct a ProgramTo Construct a ProgramIs 5% “Know that” and95% “Know how”


Learning Learning ““Knowing HowKnowing How””• The only way to learn “How” is practice• Only way to learn most of the course

material is to do homework• Purpose of lecture and textbook is to

prepare you to do this work


Extra HelpExtra Help• For some people writing a program is very

hard.– Even some people who do very well in other courses

• Extra help will be available– See Prof. Steinberg or a TA– Do so as soon as possible if you find the homework

extremely hard• Everyone should be able to pass this class, with

hard work.


MatlabMatlab• Matlab is:– A programming language– A library of programs and pieces– An Interactive Development Environment

(IDE)– A program that helps you build and test programs


Matlab Matlab as a Calculatoras a Calculator• E.g., convert 75 degrees Fahrenheit to

Celsius• E.g. convert $100 to Euros ($1 = .79 Eur.)• E.g. wall area of a room 10’ x 12’ x 8’

• Note: precedence• Note: infix vs prefix form• Note: lack of units


OperationsOperations• Plus + 4 + 5• Minus - 4 - 5• Times .* 4 .* 5• Divide ./ 4 ./ 5• Power .^ 4 .^ 5• Square root sqrt sqrt(4)• Sin sin sin(4)• … etc.


VariablesVariables• Typically, calculators have a memory;

matlab has many memory cells• Memory cell in matlab is called a

“variable”• A variable has– a name, e.g. age, year, area, …– a value


VariablesVariables• The first time you type a variable’s name,

Matlab:– Reserves a space in the computer’s memory– Associates that space with the name you

typed• After that, when you type the name,

Matlab uses the associated memory space


Using VariablesUsing Variables• To refer to a variable just type its name• Most of the time name means “the value

stored there”(degreesF - 32) .* 5 ./ 9

• To say “store this value here”, use =degreesF = 72degreesC = (degreesF - 32) .* 5 ./ 9


Why use a variable?Why use a variable?• One use: to store an intermediate result

for reuse discriminant = b.^2-4.*a.*c b + sqrt(discriminant)/(2.*a) b - sqrt(discriminant)/(2.*a)


Why use a variable?Why use a variable?• Another use: in a repetitive computation

– E.g. compute square root of 5.Use a variable named, say, root

>> root = 2root = 2>> root = (root + 5 ./ root) ./ 2root = 2.2500>> root = (root + 5 ./ root) ./ 2root = 2.2361>> root .* rootans = 5.0000


Matlab Matlab ProgramsPrograms• A Matlab program is made up of

statements– One per line

• One kind of statement is:Assignment statement


Assignment statementAssignment statement• Purpose: store a piece of data in a variable• Form:

variableName = expression• Meaning:– Evaluate expression– Store the result in the variable with name

variableName– Print the result


Assignment statementAssignment statement• May end with ; to prevent printing the

value of the expressiondegreesF = 72;


What does this do?What does this do? x = 4 + 5 y = x + 3 z = 6 .* 2 x = 1 x = x + 3


What does this do?What does this do? total = 0; total = total + 5; total = total + 8; total = total + 7


Getting helpGetting help• The help command gets help, e.g. -> help +gets help on the + operator• Also, under the Help menu, select

Product Help, type sum in “search for”box


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CS107: Computing for Math and ScienceCS107, Prof. Steinberg, f10 Lecture 01 6 What is CS107? •A...

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