CSE 333 25sp Exercise 9

out: Friday, April 25, 2025
due: Monday, April 28, 2025 by 10:00 am, No late exercises accepted.

Goals: Create and use a complete C++ class for a new 3-D Vector abstraction, including constructors, destructors, operators including assignment and stream output, and a simple user-defined namespace.

Description: Create a C++ class Vector that implements 3-D vectors.

• In file Vector.h declare a class Vector with the following properties:
  • The representation of a Vector should be three doubles giving the magnitudes in the x, y, and z directions.
  • There should be a default (0-argument) constructor that initializes a Vector to (0,0,0), a constructor with 3 doubles as parameters giving initial values for the x, y, and z magnitudes, and a copy constructor.
  • There should be a destructor that does whatever work is needed when a Vector object is deleted. If no work is needed, the body of the destructor can be empty.
  • There should be three accessor functions get_x(), get_y(), and get_z() that return the values of the x, y, and z coordinates of the Vector, respectively.
  • The class should define assignment for Vectors (u=v).
  • The class should define updating assignment for Vectors (u+=v and u-=v) that perform element-by-element addition or subtraction of the Vector components.
  • Operators + and - should be overloaded so that u+v and u-v return new Vectors that are the sum and difference of Vectors u and v, respectively.
  • Operator * should compute the inner product (dot product) of two Vectors. If v1=(a,b,c) and v2=(d,e,f), then v1*v2 should return the scalar value a*d+b*e+c*f as a double.
  • Operator * should be overloaded so that if v is the Vector (a,b,c) and k is a double, then v*k and k*v should return new Vectors containing the components of v multiplied by k (i.e., (a*k,b*k,c*k)).
  • The header should define stream output so that s<<v will write Vector v to stream s as (a,b,c), i.e., a left parentheses followed by the x, y, and z components of v separated by commas only, and a right parentheses. There should be no added spaces in the output.
  • The Vector class and associated functions should be placed in a namespace vector333.
  
  Note that several of these functions are required to return new Vectors. This means actual Vector values, not pointers or references to Vectors that have been allocated elsewhere.

• In file Vector.cc implement this class.

• In file ex9.cc write a main program that demonstrates that your Vector class works properly. The output format is up to you, but it should be labeled neatly and should be concise so it can be read with pleasure, not pain. It should show the operands and results of Vector operations, such as (1,-2,3)+(1,1,1)=(2,-1,4) so the reader can verify that the Vector operations work properly. Feel free to write using namespace vector333; in your test program so you don't need to type vector333:: repeatedly.

• Create a suitable Makefile. The command make should build an executable program ex9, recompiling individual files only when needed. The command make clean should remove the ex9 executable file, all .o files, and any editor or other backup files whose names end in ~ .

Hints: You will find the complex_example code from lecture very useful as a model for this exercise. That code demonstrates several ways to implement operators; do not feel obligated to use all of them -- use the ones that make the most sense. However, not all of the operators can be implemented as member functions of the class, so you should expect to have some non-member operator functions in your solution. Also, it is generally considered good practice to minimize the number of member functions that have access to private details inside the class if it is possible to do the job equally well with a non-member function.

You will find this exercise goes much faster if you implement operators and write test code for them one at a time, instead of trying to do everything all at once.

Feel free to base your Makefile on the one presented earlier as an example in class (i.e., you might want to download a copy of that Makefile and make suitable modifications to create one for this exercise).

Advice: get the Makefile working early, as soon as you've got a minimal set of source code to compile, and before adding all the different operations. That should save a lot of time because after each change you can just type make to re-build everything and not need to type lots of lengthy g++ commands.

Advice: Implement stream output (operator<<) early so you can use it to print Vector values using cout << v as you add operations to your Vector class.

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Your code must:

• compile without errors or warnings on CSE Linux machines (lab workstations, attu, or CSE home VM)
• have no crashes, memory leaks, or memory errors on CSE linux machines
• have a Makefile as described above that compiles the code with the g++ options -Wall -std=c++17 -g .
• Follow the style guidelines we covered in class, including naming conventions for classes, methods, and instance variables; proper use of const; and appropriate comments. If in doubt, follow the Google C++ style guide, and cpplint may be helpful in flagging potential style problems. (You can ignore cpplint complaints, if any, about using namespace directives.)
• be pretty: the formatting, modularization, variable and function names, use of const and so on must make us smile rather than cry.
• be robust: you should think about handling bogus input from the user (if any), and you should handle hard-to-handle cases (if there are any) gracefully.
• have a comment at the top of each source file with your name, and CSE or UW email address.

You should submit your exercise using the Gradescope dropbox linked on the course resources web page.