Lab 7: object vec_t

Objectives

Assignment

1. Following the class notes, define the vec_t object in the vector.h interface, providing the following class member functions:

     // constructors (overloaded)
   - (id)      init: (double) x;
   - (id)      init: (double) x: (double) y;
   - (id)      init: (double) x: (double) y: (double) z;
   
     // accessor/mutator
   - (double)  get: (int) i;
   - (void)    set: (int) i: (double) d;
   - (void)    set: (double) x: (double) y: (double) z;
   
     // operators
   - (vec_t *) plus: (vec_t *) v;
   - (vec_t *) minus: (vec_t *) v;
   - (vec_t *) scale: (double) d;
   - (vec_t *) unit;
   
   - (double)  dot: (vec_t *) v;
   - (double)  len;
   
     // friends
   - (void)    write: (FILE *) f: (char *) msg;
   	

2. All member functions (a.k.a. methods), including dot() and len(), must be implemented in the vec_t implementation vector.m
3. Your code should be such that the following main() routine works unaltered:

   #import <Foundation/Foundation.h>
   
   #import <stdio.h>
   #import <vector.h>
   
   //---- program section ----
   
   int main(int argc, const char *argv[])
   {
           NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
   
           vec_t *v1 = [(vec_t *)[vec_t alloc] init: 3.0: 4.0: 5.0];
           vec_t *v2 = [(vec_t *)[vec_t alloc] init];
           vec_t *v3 = nil, *v4 = nil, *v5 = [v1 copy];
   
     NSLog(@"main start");
   
   //[v1 set: 3.0:  4.0:  5.0];
     [v2 set: 4.0: -1.0:  2.0];
   
     [v1 write: stderr: "v1 is:"];
     [v2 write: stderr: "v2 is:"];
   
     // v3 allocated by minus operator, which we retain (must release later)
     v3 = [[v2 minus: v1] retain];
   
     [v3 write: stderr: "v2 - v1 is:"];
   
     // example of "transient" memory use where we don't retain memory
     [[v2 minus: v1] write: stderr: "v2 - v1 is:"];
   
     fprintf(stderr,"v1 dot v2 is: %f\n", [v1 dot: v2]);
   
     fprintf(stderr,"length of v1 is: %f\n", [v1 len]);
   
     // memory leak?  no...scale returns an autorelease object
     [[v1 scale: 1./[v1 len]] write: stderr: "v1 scaled by 1/length is:"];
   
     // memory leak?  no, unit returns autorelease object whcih we retain
     v4 = [[v1 unit] retain];
     [v4 write: stderr: "unit vector in v1 direction:"];
   
     [v1 release];
     [v2 release];
     [v3 release];
     [v4 release];
   
     [v5 write: stderr: "v5 is:"];
     [v5 release];
   
     [pool drain];
   
     return 0;
   }
   	

4. Use the following Makefile to compile the vector library into a libvec.a library that other programs can use (be careful where tabs are required!).

   
   .SUFFIXES: .m
   
   UNAME   = $(shell uname)
   
   CC      = gcc
   
   ifeq ($(UNAME),Linux)
   #CFLAGS = -g -fconstant-string-class=NSConstantString
   CFLAGS  = -g `gnustep-config --objc-flags`
   INCLUDE = -I. -I/usr/include/GNUstep
   LDFLAGS = -L. -L/usr/lib -L/usr/lib/GNUstep
   LDLIBS  = -lgnustep-base
   endif
   
   ifeq ($(UNAME),Darwin)
   #CFLAGS = -g -x objective-c -arch i386 -mmacosx-version-min=10.5
   #CFLAGS = -g -arch i386 -mmacosx-version-min=10.5
   CFLAGS  = -g -mmacosx-version-min=10.6
   INCLUDE = -I.
   LDFLAGS = -L. -L/usr/lib
   LDLIBS  = -framework Foundation
   endif
   
   .m.o:
           $(CC) -c $(INCLUDE) $(CFLAGS) $<
   
   OBJS = \
   vector.o \
   main.o
   
   all: main
   
   main: main.m $(OBJS)
   #       $(CC) $(CFLAGS) $(INCLUDE) -o $@ $(OBJS) $(LDFLAGS) $(LDLIBS)
           $(CC) -o $@ $(OBJS) $(LDFLAGS) $(LDLIBS)
   
   clean:
           rm -f *.o core
           rm -f main
   	

5. Sample output (note that the first line with the timestamp will be different):

   2013-01-15 13:25:56.652 main[47843:903] main start
   v1 is:   3.000   4.000   5.000
   v2 is:   4.000  -1.000   2.000
   v2 - v1 is:   1.000  -5.000  -3.000
   v2 - v1 is:   1.000  -5.000  -3.000
   v1 dot v2 is: 18.000000
   length of v1 is: 7.071068
   v1 scaled by 1/length is:   0.424   0.566   0.707
   unit vector in v1 direction:   0.424   0.566   0.707
   v5 is:   3.000   4.000   5.000
   	

Turn in

1. A README file containing
   1. Course id--section no
   2. Name
   3. Lab description
   4. Brief solution description (e.g., program design, description of algorithm, etc., however appropriate).
   5. Lessons learned, identified interesting features of your program
   6. Any special usage instructions
2. Makefile
3. source code (.h headers and .m source)
4. object code (do a make clean before tar)

How to hand in