CSC231m Lecture 18

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CSC-231m Lecture 18

• Other Languages
• Progress
• Programmers Toolbox

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Todays Topics

• How to do HW9.
• Other high-level languages.
• Where to get free compilers.
• Syntax and semantics.
• Your own toolbox.

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Files Needed in HW9 Part A

• hw9a.m from /home/mhutchen/csc231
• YOUR very own function MyFunc.m
• YOUR very own function MyOtherFunc.m
• For example
• function dRtn MyFunc (dInput)
• dRtn dInput.2 4dInput 12
• return

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Plotting Reminder

• case 2
• fhTwo _at_Myfunc
• dResult dMySimp (fhTwo, 1, 5, 500)
• disp (The result is num2str(dResult))
• dX 1 (5 1)/500 5
• dY MyFunc (dX)
• labels
• plot (dX, dY)

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Other High-Level Languages

• Pascal led to Ada and was updated further as
  Modula2. These will be discussed and compared to
  MATLAB.
• C led to C, which led to Java and C. These
  will be discussed and compared to MATLAB.
• Fortran went through Fortran IV and Watfor to
  Fortran 77, Fortran 90, Fortran 95, and beyond.
  BASIC is somewhat derived from Fortran and comes
  in many flavors. These will also be compared to
  MATLAB.

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Interpreted vs. Compiled

• Basic is generally interpreted as is Java.
• However, it is also possible to compile these
  languages.
• Interpreted languages need a runtime environment
  to run within.
• MATLAB is interpreted.
• All other languages are compiled.
• A standalone executable file is created and run
  within an operating system rather than a runtime.

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Proprietary vs. Standard

• MATLAB, Java, and C are proprietary. Their
  features are controlled by a particular company
  (MathWorks, Sun, and Microsoft respectively).
• C, C, and Fortran are standard. Features are
  controlled by ANSI/ISO committees. The advantage
  of standardization is that any compiler can
  compile and run a program developed with a
  different compiler without modification.
• Many Basic versions are proprietary, in fact I am
  not sure there is a standard Basic out there.

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C Family of Languages

• UNIX was originally written in machine language.
  C was developed to rewrite UNIX in a high-level
  language.
• C was itself derived from B, which was derived
  from BCPL (Basic Combined Programming Language ).
• C is literally an increment of C to add the
  concept of a class and object oriented design.
  Since C was the third language to come from
  BCPL, some argued it should be called P and
  others argued it should be called D.
• Java evolved from C. Here, some argued this
  should be called C--, one step forward, one
  back.
• Then came the lawsuits

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Microsoft vs. Sun

• Microsoft created J as part of their Visual
  Studio. However, J is pretty much Java 1 and
  not fully compatible with Java 2 from Sun.
• Sun sued to keep Microsoft from calling their J
  Java and made them stop using the coffee-cup logo
  of Java.
• Microsoft retaliated by creating C and the
  expanded .NET concept.
• The battle ultimately still continues.

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Why No Standard Java?

• Java began life as a proprietary language for
  embedded computers, like those in household
  appliances.
• The creation of the World Wide Web was an
  opportunity to take Java beyond embedded
  computers, although the Java Virtual Machine is
  ultimately an embedded simulated computer.
• Were Sun to allow a committee to create an
  ISO/ANSI standard Java, they would lose control
  of their language. Time will tell if this is wise.

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In Case You Have Forgotten

• script M-file hw2a.m
• fCels 0.0
• fFahr 0.0
• disp ('This program converts Celsius to
  Fahrenheit')
• fCels input ('Enter a temperature in degrees C
  ')
• fFahr ((9.0/5.0) fCels) 32.0
• disp (num2str(fCels) ' degrees C is '
  num2str(fFahr) ' degrees F')

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In C This Would Be

• Homework 2, hw2a.c /
• include ltstdio.hgt
• int main (int argc, char argv)
• float fCels 0.0
• float fFahr 0.0
• printf ("Enter temperature in degrees Celsius
  ")
• scanf ("f", fCels)
• fFahr ((9.0/5.0) fCels) 32.0
• printf ("f degrees C f degrees F\n", fCels,
  fFahr)
• return (0)

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In Pre-Std C This Would Be

• // Homework 2, hw2a.cpp, pre-standard
• include ltiostream.hgt
• int main (int argc, char argv)
• float fCels 0.0
• float fFahr 0.0
• cout ltlt "Enter a temperature in degrees
  Celsius " ltlt endl
• cin gtgt fCels
• fFahr ((9.0/5.0) fCels) 32.0
• cout ltlt fCels ltlt " degrees C " ltlt fFahr ltlt
  " degrees F" ltlt endl
• return (0)

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In Standard C It Is

• // Homework 2, hw2a.cpp, pre-standard
• include ltiostreamgt
• using namespace std // otherwise stdcin and
  stdcout
• int main (int argc, char argv)
• float fCels 0.0
• float fFahr 0.0
• cout ltlt "Enter a temperature in degrees
  Celsius " ltlt endl
• cin gtgt fCels
• fFahr ((9.0/5.0) fCels) 32.0
• cout ltlt fCels ltlt " degrees C " ltlt fFahr ltlt
  " degrees F" ltlt endl
• return (0)

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Now In Java

• // Homework 2, hw2a.java
• import cs1.Keyboard
• public class hw2a
• public static void main (String args)
• float fCels 0.0f
• float fFahr 0.0f
• System.out.println("Enter a temperature
  in degrees Celsius\n")
• fCels Keyboard.readFloat()
• fFahr ((9.0f / 5.0f) fCels) 32.0f
• System.out.println(fCels " degrees C is
  equal to "
• fFahr " degrees
  F.\n")

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On To C...

• // Homework 2, hw2a.cs
• using System
• class hw2
• static void Main (string args)
• float fCels 0.0
• float fFahr 0.0
• Console.WriteLine (Enter a temperature in
  degrees Celsius )
• fCels float.Parse (Console.ReadLine())
• fFahr ((9.0/5.0) fCels) 32.0
• Console.WriteLine (0 degrees C 1 degrees
  F\n, fCels, fFahr)

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Common To All

• if (fCels lt fLOWER) ...
• else if (fCels gt fUPPER) ...
• else ...
• for (iLoop 1 iLoop lt 10 iLoop) ...
• while (cQuit ! q) ...
• do ... while (cQuit ! q)
• switch (cAction)
• case a
• case A
• break
• default

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Functions in C

• float fCels, fFahr
• float fAmount
• int iDoll, iQuar, iDime, iNick
• fCels fCelsToFahr (fCels)
• Change (fAmount, iDoll, iQuar, iDime, iNick)
• float fCelsToFahr (float fCelsius)
• float fFahren
• ...
• return (fFahren)
• void Change (float fAmt, int piDoll, ..., int
  piNick)
• piDoll (int)fAmt
• ...

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Functions in C

• float fCels, fFahr
• float fAmount
• int iDoll, iQuar, iDime, iNick
• fCels fCelsToFahr (fCels)
• Change (fAmount, iDoll, iQuar, iDime, iNick)
• float fCelsToFahr (float fCelsius)
• float fFahren
• ...
• return (fFahren)
• void Change (float fAmt, int iDoll, ..., int
  iNick)
• iDoll (int)fAmt
• ...

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Meanwhile, Over In Fortran

• ! Homework 2, hw2a.f90
• PROGRAM TempConv
• IMPLICIT NONE
• REAL rCels 0.0
• REAL rFahr 0.0
• PRINT , "Enter a temperature in degrees Celsius
  "
• READ , rCels
• rFahr ((9.0/5.0) rCels) 32.0
• PRINT , rCels, " degrees C ", rFahr, " degrees
  F"
• END PROGRAM TempConv

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Other Statements

• IF (rCels lt rLOWER) THEN
• ELSE IF (rCels gt rUPPER) THEN
• ELSE
• END IF
• DO iLoop 1, 10, 1
• END DO
• DO
• IF (cQuit q) EXIT
• END DO
• SELECT CASE (cAction)
• CASE (a, A)
• CASE DEFAULT
• END SELECT

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Functions in Fortran

• rFahr rCelsToFahr (rCels)
• FUNCTION rCelsToFahr (rCelsius)
• REAL rCelsToFahr
• REAL, INTENT(IN) rCelsius
• rCelsToFahr (9.0/5.0) rCelsius 32.0
• END FUNCTION
• CALL Change (rAmount, iDoll, iQuar, iDime, iNick)
• SUBROUTINE Change (rAmt, iDol, iQua, iDim, iNic)
• REAL, INTENT(IN) rAmt
• INTEGER, INTENT(OUT) iDol, iQua, iDim, iNic
• END SUBROUTINE

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And In QuickBASIC

• REM Homework 2, hw2a.bas
• LET rCels 0.0
• LET rFahr 0.0
• PRINT Enter a temperature in degrees Celsius
• INPUT rCels
• rFahr ((9.0/5.0) rCels) 32.0
• PRINT rCels degrees C rFahr degrees F
• END

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Other Statements

• IF rCels lt LOWER THEN
• ELSEIF rCels gt rUPPER THEN
• ELSE
• END IF
• FOR iLoop 1 TO 10
• NEXT iLoop
• DO WHILE (cQuit ltgt q)
• LOOP
• DO
• LOOP UNTIL cQuit q
• SELECT CASE cAction
• CASE a, A
• CASE ELSE
• END SELECT

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Functions and Subroutines

• rFahr rCelsToFahr (rCels)
• CALL CHANGE (rAmt, iDol, iQua, iDim, iNic)
• FUNCTION rCelsToFahr (rCelsius)
• rCelsToFahr ((9.0/5.0) rCelsius) 32.0
• END FUNCTION
• SUB Change (rAmount, iDoll, iQuar, iDime, iNick)
• iDoll INT(rAmount / 1.00)
• rAmount rAmount (iDoll1.00)
• iQuar INT(rAmount / 0.25)
• ...
• END SUB

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Basics of BASIC

• QuickBASIC from Microsoft was a compiled BASIC
  environment, you created programs that compiled
  into standalone executables.
• QBasic was the next step, but it was an
  interpreted language. You had to run your
  programs within the QBasic runtime environment.
• Visual Basic is the next step. It is based on a
  graphical user interface (GUI), see next slide.
• Other companies have created other BASIC versions
  including TrueBASIC.

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Visual Basic

• The window (form) is laid out graphically.
• The underlying code is then written. In this
  case
• The user enters a temperature in the top edit
  box.
• The user clicks on the Convert button.
• The converted temperature is displayed in the
  lower edit box.

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And Now in Pascal

• ( hw2.pas )
• PROGRAM hw2
• VAR rCels, rFahr real
• BEGIN
• writeln ('Enter a temperature in degrees
  Celsius ')
• readln (rCels)
• rFahr ((9.0/5.0) rCels) 32.0
• writeln (rCels, ' degrees C is ', rFahr, '
  degrees F.)
• END.

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Other Constructs in Pascal

• IF x lt 10 THEN BEGIN
• END
• ELSE IF x gt 50 THEN BEGIN
• END
• ELSE BEGIN
• END
• CASE choice OF
• label list statement
• ELSE
• END
• WHILE digit lt n DO
• BEGIN
• END
• FOR count 1 TO n DO
• BEGIN
• END
• REPEAT
• UNTIL digit gt n

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Functions in Pascal

• FUNCTION rCelsToFahr (rCel real) real
• VAR
• BEGIN
• rCelsToFahr ((9.0/5.0) rCels) 32.0
• END

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Subroutines (Procedures)

• PROCEDURE Change (rAmt real VAR iDol, iQua,
  iDim, iNic integer)
• BEGIN
• iDol int (rAmt / 1.00)
• rAmt rAmt (iDol 1.00)
• END

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A Taste of Ada

• WITH Text_IO
• PROCEDURE hw2 IS
• fCels Float
• fFahr Float
• BEGIN
• Text_IO.Put (Item gt Enter a temperature in
  degrees Celsius )
• Text_IO.NewLine
• Text_IO.Get (Item gt fCels)
• fFahr ((9.0/5.0) fCels) 32.0
• Text_IO.Put (Item gt fCels)
• Text_IO.Put (Item gt degrees C is )
• Text_IO.Put (Item gt fFahr)
• Text_IO.Put (Item gt degrees F.)
• Text_IO.New_Line
• END hw2

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More Ada

• IF x gt 10 THEN
• ELSE
• ELSIF x lt 1 THEN
• END IF
• FOR counter IN 1..repetitions LOOP
• END LOOP
• WHILE x lt 42 LOOP
• END LOOP
• LOOP
• EXIT WHEN x lt 42
• END LOOP
• CASE cChoice IS
• WHEN M gt
• WHEN OTHERS gt
• END CASE

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Functions and Procedures

• FUNCTION fCelsToFahr (fCels Float) RETURN
  Float
• fFahr Float
• BEGIN
• fFahr ((9.0/5.0) fCels) 32.0
• RETURN fFahr
• END fCelsToFahr
• PROCEDURE Change (fAmt IN Float iDol OUT
  Integer iQua OUT Integer iDim OUT Integer
  iNic OUT Integer) IS
• BEGIN
• iDol Integer (fAmt / 1.00)
• fAmt fAmt (Float(iDol) 1.00)
• END Change

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A Bit of Modula 2

• Module hw2
• IMPORT
• VAR rCelsius, rFahren REAL
• PROCEDURE rCelsToFahr (rCels REAL)REAL
• VAR rFahr REAL
• BEGIN
• rFahr ((9.0/5.0) rCels) 32.0
• RETURN rFahr ( note no semicolon )
• END rCelsToFahr
• BEGIN
• IO.StringOut (Enter a temperature in degrees
  Celsius )
• IO.RealIn (rCelsius)
• rFahren rCelsToFahr (rCelsius)
• IO.FloatOut (rCelsius, 1, 2) ( minimum space,
  2 decimal places )
• IO.StringOut ( degrees C is )
• IO.FloatOut (rFahren, 1, 2)
• IO.StringOut ( degrees F.)
• IO.LineOut
• END hw2.

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Where To Get Free Compilers

• For C and C, go to Borland and get their
  CBuilder. It comes with an integrated
  development environment (like MATLAB) and will
  handle both C and C.
• http//www.borland.com/downloads/download_cbuilder
  .html
• For Java, go to Sun. MATLAB installs a Java
  runtime also.
• http//java.sun.com/j2se/1.4.2/download.html
• For Fortran95, go to Salford Software
• http//www.salfordsoftware.co.uk/software/download
  s/compilers.html

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What About MATLAB?

• It is probably closest to C, with a bit of
  Basic/Fortran mixed in.
• You can create GUI applications as with Visual
  Basic (or Visual Whatever in Visual Studio).
• You can create GUI applications as with Java.

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MATLAB Alternatives

• There appear to be four free alternatives to
  MATLAB, based on a Google search
• DADiSP
• Scilab
• Octave
• FreeMat
• Disclaimer I have not tried any of these.

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DADiSP
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Scilab
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Octave
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FreeMat
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Discipline, Etc.

• This course was intentionally rigorous and
  structured.
• MATLAB, or any other language is all about
• Syntax the form of statements.
• Semantics the meaning of those statements.
• A lot of time was spent on style issues.
• Consistent style leads to fewer programming
  errors and less frustration.
• What you ultimately learned was simply discipline

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Syntax

• Given the following statement
• for iLoop 1110
• Syntax refers to the form of the statement
• The for statement.
• Variable iLoop is initially set to 1, incremented
  by 1 each time through the loop, and stops at 10.
• The three numbers are separated by colons.

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Semantics

• Semantics refers to the meaning of the statement
• Variable iLoop is initially set to 1, and the
  test expression is true, since iLoop lt 10.
• The statements in the loop are executed.
• At the end of the loop, variable iLoop is
  incremented.
• Variable iLoop is compared to 10.
• If it is less than or equal to that, the loop is
  executed again.
• If it is greater than that, the loop terminates.

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The Tool Problem

• Old Adage
• When your only tool is a hammer, every problem
  looks like a nail.
• Fortunately, the hammer is not your only tool.

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Programmers Toolbox

• Top area basic data types, arrays, and strings.
• First drawer basic program elements, input, and
  output.
• Second drawer branching and looping constructs.
• Third drawer functions.
• Fourth drawer miscellaneous elements, like
  files.
• Documentation headers.

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Using the Proper Tool

• Given the need to open a switch plate on your
  wall
• A wrench wont help, nor will pliers.
• Your fingernail probably isnt strong enough.
• A knife might work.
• You can break the plate off with a hammer, but
  only if the plate is plastic.
• For this task, you need a screwdriver.

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Pedagogy

• (Defined as the art or science of teaching.)
• In the curriculum of computer programming, it is
  widely accepted that students learn by
  progressing through three steps
• Copy someone elses program and run it (hw1d,
  hw2a).
• Modify someone elses program and run it (hw3a,
  etc.).
• Create a program of their own and run it (pr2,
  etc.).
• As you can see, we did all three of these early
  and often.

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Progress

• Week 1 Whats the difference between an integer
  and a float?
• Stuff happened.
• Week 10 You submit a running 100-line program of
  your own design.

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Todays Lessons

• You should realize that while you learned MATLAB,
  you also learned how to effectively program in
  any other language.
• You should be able to get a free compiler for
  another language if you choose to do so.
• You should understand why I stress syntax and
  semantics so much.
• You should be able to design, code, test, and use
  a complex program for a project of your own.