CMPT 102 Introduction to Scientific Computer Programming · CMPT 102: Introduction to Scientific ... 6The C Programming Language Authors: ... DBefore you can use any of the computers

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0© Janice Regan, CMPT 102, Sept. 2006

CMPT 102Introduction to Scientific Computer Programming

Course Organization

© Janice Regan, CMPT 102, Sept. 2006 1

CMPT 102: Introduction to Scientific Computer Programming

Monday, Wednesday, Friday 9:30-10:20Textbook:

C Program Design for EngineersAuthors: Jeri R. Hanly, Elliot B. Koffman

Additional References:Engineering Problem Solving with C, 3rd editionAuthor: Delores M. Etter

The C Programming LanguageAuthors: B. W. Kernighan, D. M. Ritchie

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Class web-siteAll the information discussed today and more can always be found on the class web-siteTo find the class web site go to http://www.cs.sfu.ca/CourseCentral

Select Course Home pagesSelect the Homepage for CMPT 102

Course Central is also a useful link to abundant information useful to students taking a computing science course


http://www.cs.sfu.ca/CourseCentral

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Course selection page

Click here to go

to CMPT102 website


CMPT 102 Website

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My availability


Exams Dates, Course Evaluation

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Exams and Evaluation


EvaluationAssignments: 30% Weekly Quizzes: 15%

No quiz in week of midterm, week of Thanksgiving or week of Remembrance day

Lab Problems: 5% Practice Problems: no creditMidterm Examination: 15% Final Examination: 35%

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Assignments

Four assignments Each assignment worth 7.5% of your course grade Assignments are to be completed individuallyProblems similar to the assignments will appear on the midterm and the final.Help is available during weekly lab hoursComplete solutions will be posted


Lab Problems

Four short lab problems Each lab problem is worth 1.25% of your final grade Practice Problems: no credit BUT valuable experience that will be useful when completing lab problems and assignments

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QuizzesDuring each Wednesday’s lecture, you will be asked to answer one question based on material covered in the lab exercises that week.

You will be asked to write a short concise paragraph of 10-15 sentences, explaining a concept or method, or a short piece of code. You will be given 10-15 minutes to answer.Your answer will be graded out of 17 (each quiz is worth 1.7% of your final grade)


Midterm and FinalOne 50 minute in class midtermOne 3 hour final examination35% short answer problems65% longer problems that utilize several important concepts and require integration of those concepts. A sample exam, including solutions, will be posted two weeks before the midterm and two weeks before the final exam

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Assignments, Labs, Solutions


Important Dates

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AssignmentsAt least two weeks before the due date the assignment will be posted on the website

Assignments must be completed individuallyAssignments will require you to combine and use many concepts and tools you have learnedAssignments will be much more demanding than lab problems or practice problemsComplete solutions to all assignments will be posted Information of proper preparation of assignments and lab problems is available on the class website.


LabsOn or before Friday of each week problems will be posted for the next week. These problems will be identified as

Lab Problems: To be completed individually or in a small group (up to four students)

Submitted for gradingPractice Problems: A chance to use a new idea in a simple application, before you need to integrate multiple ideas into assignments.

Collaboration is encouragedNot submitted for grading

Complete solutions to all problems will be posted

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Grading InformationAssignments and Lab Problems should be:

submitted electronically using the submission serversubmitted in hard copy to the 102 drop box

Bonus points (10%) are available for submitting assignments more than 72 hours earlyNo late assignments or lab problems will be acceptedUnofficial grades will be available on GradeBook

Login: your SFU computer ID, your student number as password. Find link on Course Central


Where to submit assignments: 1

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Where to submit assignments: 2

Submission drop boxes


Required Readings, Notes

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Readings and Notes


Academic Honesty

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Academic Honesty

Read the policy


Getting Started

If you have not already done so activate your SFU computing account (CCN, Campus Computing Network account.)

Use your own machine at home, or go to the assignment lab (AQ 3145)Email regarding the class will be sent to your Campus Account, so check it regularlySteps to activate your account …

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Activating your CCN account (1)

Select mySFU


Activating your CCN Account (2)

Select Apply for ID, the follow the instructions. You will need your student ID and your TeleReg PIN

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Computing Science Instructional Labs (CSIL)

The CSIL LINUX lab is available for your use at all times beginning in the second week of classes. (ASB 9838)At particular times the instructor and/or TA will be available in the lab to answer your questions.

Instructor: Mon. 1:30-3:00 PM,Tue: 9:00-10:30 AM

TA: Tue: 10:00 – 10:30 AM. TBA


Finding CSIL labs: 1

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Finding CSIL labs: 2

CSIL Labs


Access to CSIL

CSIL is protected by a security card access system

As a student in a computing science course you are eligible to have a security access card for CSILIf you are pre-registered your access card may be picked up from the card office at traffic and security (there is a $15 refundable deposit and a $3 processing fee)

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CSIL RulesBefore you can use any of the computers in the CSIL you must sign and return an ethics form.

By signing the ethics form you indicate that you have read and agree to abide by the SFU and CSIL regulations regarding use of computing resources and computer labs. Links to these policies can be found on the class website or on Course CentralYou can return your ethics forms during next class, or directly to the computing science main office.


http://www.cs.sfu.ca/CourseCentral

Select to reach Policies

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CSIL page

IMPORTANTRead thePoliciesBefore Signing

Your Ethics form


Getting Started in CSIL

Before you try programming in CSIL read the information provided for you

Read the general information pagesBrowse the FAQs, Now you are ready to start

Your CSIL computer ID and password and the ID an password you use for your SFU email account.

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CSIL page

Read thegeneral

information

Browse The

FAQs


Labs and using CSIL

The computers in CSIL are available 24/7At some times your instructor or TA will be available to answer questionsAt some times OPEN LAB TA’s will be available to answer questions.A list of TA’s presently in the lab will be posted on the white board in CSIL.

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Optional Lab HoursAttendance at optional Lab hours is strongly encouraged

Lab Hours are held in the LINUX area of CSIL labs Lab Hours provide an opportunity to work with others sharing knowledge and experience. Lab Hours give you an opportunity to ask the instructor or TA one on one questions about problems and assignments. Lab Hours help you learn the required concepts one by one and allow you to ask questions to assure you understand each one.


Operating System

In the CSIL labs you will be using computers that run the LINUX operating systemIn the first optional lab hours there will be tutorials on how to use the LINUX operating system (1 per hour)The tutorial will also be posted so you can try it yourself at another time

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Reading AssignmentVisit and read the information on the class websiteBe sure you can find

Posted notesReading assignments for each lecture Assignment due datesInstructions on using the CSIL labsInstructions on using your own computer for assignments

Have any questions ready for next lecture

41© Janice Regan, CMPT 102, Sept. 2006

CMPT 102Introduction to Scientific Computer Programming

Chapter 1: Computer Components

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Hardware and Software

A computer is a machine designed to perform operations specified with a set of instructions called a program.Hardware refers to the computer equipment.

keyboard, mouse, terminal, hard disk, printer, CPASoftware refers to the programs that describe the steps we want the computer to perform.


CPU

Computer Hardware

CPU –Central processing unit

ALU –Arithmetic and logic unit

ROM –Read only memory

RAM –Random access memory

InternalMemory

ExternalMemory

Input OutputProcessor

ALU

Cache/Memory

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Software: Operating System

A system of computer programs that control the interaction of the user and the computer hardware. Examples: Linux, Windows, QNX,…Purposes of the operating system

Controls communication between input and output hardware and each process running in the computer.Directs and orders all operations of the computerAllocates and shares resources (memory,processor…)Controls access to resources and data (security)Provides a user interface (UI) and/or graphical user interface (GUI)Stores and accesses data and applications


Example: Command Line UI

Windows Command Prompt

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Example: Graphical UI (GUI)

Windows explorer


Computer Software: Applications

Application Software (Software Tools)Word processors (Microsoft Word, WordPerfect, ...)Spreadsheet programs (Excel, Lotus1-2-3, ...)Computer gamesCommunication software (email, chat, web browser…)Telecommunication software (VOIP, …)

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Computer Software: Languages

Some Computer LanguagesMachine language (machine instruction set)assembly languagehigh level languages

C, C++, Ada, Fortran, Basic, JavaDo YOU know of any others?mathematical computation tools (MATLAB, Mathematica, ...)

Application software is written using computer languages.


Machine languageEach type of processor (like Pentium 4, Athalon, Z80, …) has its own instruction setEach instruction in an instruction set does a single thing like access a piece of data, add two pieces of data, compare two pieces of data …Each instruction is represented by a unique number This # may be different for different instruction sets, but no two instructions in the same instruction set will have the same #

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Machine Language programs

In machine language a program is a list of instructions

Each instruction is represented by a numberInside the memory of the computer each number is represented in binary (as a constant length string of 1’s and 0’s)The long string of 0’s and 1’s is easy for the computer to understand and very difficult for a Human to read or write


Assembler

Assembler languages make it easier for the programmer.

Assembler is easier for humans to read/write The numbers that identify each of the instructions in the instruction set are replaced with mnemonics like ADD, CMP, …The code, written using these mnemonics is written into a text file.

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Assembler ProgramsThe code for an Assembler program is written into a text file.The computer read 1’s and 0’s not textHow do we translate to machine readable form?

A computer program called a compiler is used to translate the text file (called a source file) containing the assembler code into machine readable codeThe compiler writes a binary file containing the machine readable code (called an object file)


Programs in High Level Languages

Assembler is easier to read/write than machine language. It is still very cumbersomeHigh level languages are easier to write than assembler

The compiler is more complex, but that is a tool you use, not one you write

In this course we will learn the language CThe rest of today's discussion is equally applicable to C or to any other compiled language (C++, Fortran, …)

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Writing your program

Editor, Type inyour program

Source File

Text saved on hard disk

CompilerTranslate text into

Machine Readable code


Source filesContains the text you type into a text editorThe text is a programThe program is a list of instructions written in a special Human readable language (C)The program can be translated, from the Human readable language (in source file) to a machine readable language (in object file), by a compilerA compiler is a special piece of software used to translate from source files to object files

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Source files

Source File: Write using a text editor like KateDo not write your code using a word processor like Microsoft Word. A word processor will save in a special format.The compiler reads only text, not special formats.

Beware: your text does not differentiate between a word processor and an editor


Perfect Code? Finding Errors 1It is highly unlikely than any of us will always write perfect code that contains no errorsHow do we find errors? Are there different kinds of errors? YesA computer program can contain syntax errors. semantic errors, or logical errorsWhen and how can we detect and correct errors?

Compile errorsLink errorsRun Time Errors

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Syntax ErrorsA computer program can contain syntax errorsA computer language follows simple rules

how words and punctuation of different types may be combined.In English syntax is similar to grammatical structure

The compiler for a high level language can detect errors that break those simple of syntax (syntax errors)Syntax Errors are usually detected at compile time


Semantic ErrorsA computer program can contain semantic errorsSemantics relates to the meaning of the words in a sentence or a computer language commandJust like a grammatically correct English sentence can be nonsense, a syntactically correct high level computer language command can also contain semantic errorsSome semantic errors may be found by the compiler, some will be found when the program is linked, some may be found at run time

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Logical Errors

When your program completes but gives an unexpected answer it usually means there is a error in the logic in your solution of the problemLogic errors can also cause a program to fail part way through execution


Writing your program

Editor, Type inyour programSource File

CompilerTranslation toMachine code

Syntax or Semantic Errors, Compiler Generates error Messages. To help us findand Correct errors in the

Source File

Object File

Binary,machine readable file

Syntactically Correct

code

Code with

syntax

Or semantic

errors

Editor, CorrectSyntax Errors

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Perfect Code? Finding Errors 2If your code contains compile time errors is it correct? NOT NECESSARILYHow do we find the remaining errors? Use a tool that does more checks than the compiler (splint). Move on to linking the code to libraries etc.

The linker resolves references, words in your program than are defined elsewhereErrors occur when the definitions cannot be foundErrors occur when the use of the word does not correspond to the definition


Linking your programEditor, Enter

program

Source File

(Text)

CompileFind Syntax

and SemanticErrors

Object File

(binary)

CorrectErrors

LinkerResolves

References among

object files

Other Object FilesLibraries …

Executable File(load module)

(binary)

Semantic Errors Reported: Finds words with no defined meaning.

Code has linker errors

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Perfect Code? Finding Errors 3

If your code compiles and contains no errors that can be found by the linker (or splint) is it correct? NOT NECESSARILYHow do we find the remaining logic and semantic errors?When you run your executable program

it may not complete (may or may not generate error message)It may complete and give the wrong answer


Loading/Running your programEditor, Enter

program

Source File

(Text)

CompileFind Syntax

and someSemanticErrors

Object File

(binary)

CorrectErrors

LinkerResolves

References

Other Object Files

Executable File(binary)

Link Errors Reported:

LoaderCopies

ExecutableAnd Runs

Input data

output resultsCPU

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Summary:Executing a Computer Program

CompilerConverts a source file (containing your human readable program in C) to and object file (computer readable binary file)

LinkerConverts object program to executable program

Compile Link/load ExecuteC languageProgram inText file(source file)

MachinelanguageProgram In binary file(object file)

Program output

Input data

Otherobject files


Summary: Types of ErrorsSyntax errors

Errors in syntax, how words are combined and usedreported by the compiler or splint

Semantic errorsErrors in the meaning of words,

Reported by the linker (linker errors)Reported by the compiler (compile time errors)Found at execution time (run-time errors)

Logic errorsErrors causing the incorrect results, not reportedErrors causing program failure (run-time errors)

Documents

CMPT 102 Introduction to Scientific Computer Programming · CMPT 102: Introduction to Scientific ... 6The C Programming Language Authors: ... DBefore you can use any of the computers