A7
.pdf
School
University of Saskatchewan**We aren't endorsed by this school
Course
CMPT 141
Subject
Computer Science
Date
Dec 21, 2024
Pages
6
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Department of Computer Science176 Thorvaldson Building110 Science Place, Saskatoon, SK, S7N 5C9, CanadaTelephine: (306) 966-4886, Facimile: (306) 966-4884CMPT 141Fall 2024Introduction to Computer ScienceAssignment 7ArraysDate Due: 5:00pm Friday Nov 8Total Marks: 15General Instructions•This assignment is individual work.You may discuss questions and problems with anyone, butthe work you hand in for this assignment must be your own work.•Each question indicates what to hand in. You must give your document the name we prescribefor each question, usually in the form aNqM, meaning Assignment N, Question M.•Make sure your name and student number appear at the top of every document you hand in.These conventions assist the markers in their work. Failure to follow these conventions will resultin needless effort by the markers, and a deduction of grades for you.•Do not submit folders, or zip files, even if you think it will help. It might help you, but it adds anextra step for the markers.•Programs must be written in Python 3.5+•You may not, in part or in whole, submit any code that was written by generative AI tools, such asChatGPT•Assignments must be submitted to Canvas (the course website).•Canvas will not let you submit work after the assignment hand-in closes.It is advisable to handin each answer that you are happy with as you go. You can always revise and resubmit as manytimes as you like before the deadline; only your most recent submission will be graded.•Read the purpose of each question. Read the Evaluation section of each question.
Department of Computer Science176 Thorvaldson Building110 Science Place, Saskatoon, SK, S7N 5C9, CanadaTelephine: (306) 966-4886, Facimile: (306) 966-4884CMPT 141Fall 2024Introduction to Computer ScienceQuestion 1 (10 points):Purpose:To practice string and file manipulation; to solve a problem using numpySolving systems of (linear) equations is a common task in mathematics. For example, here is a small systemof three equations with three unknowns:2x+y+3z=95x+3y+z=15x+7y+12z=0Solvingthe system means finding numeric values for all the unknowns, in this case,x,y, andz, such thatall three equations are simultaneously true.Small systems of equations can be solved by hand, but most programming languages, and certainlyPython, have libraries that can solve them for you. You’ll explore that idea in this question.Using NumpyThe programming parts of this assignment will require using thenumpymodule. This module is NOT stan-dard, so if you are working on your own machine, you may need to install it first. Depending on how youinstalled Python, this can hopefully be as easy as pulling up a terminal and typingconda install numpy.Part 1: Hand SolveFirst solve the system of equations found in the provided filesystem1.txt(it’s the same one as the exampleshown just above). Do it by hand using any method you like, but without using a program of any kind. Showyour work and hand it in. You can round any decimal numbers in your final answer to 4 figures of precision.Part 2: Solve using numpyTo verify your work from part 1, write a very small program that uses the numpy module to solve the systemof equations fromsystem1.txt. The method you need from the numpy module isnumpy.linsolve.solve().The only trick comes from figuring out the format that you need to use for your system in order to ’feed itin’ to thesolve()method.In order to do that, go ahead and use ChatGPT! Go to ChatGPT (or any other large language model thatyou like) and ask it something like "show me a simple example of how to solve systems of linear equationsin Python". Don’t tell ChatGPT anything about your SPECIFIC system of equations. Just use the exampleit gives you to write your own program that solves that system. Most likely your program will be no morethan 5 lines of code. Check it against the answer you figured out by hand, and then hand this program in.Part 3: Write an equation parserTake a look at the systems of equations found insystem2.txtandsystem3.txt. Would you want to solvethese systems by hand or even manually plug them in to the format thatnumpy.linsolve.solve()requires?If you said ’no’, then good. You’re ready for the main part of this question.Your last task is to write a program that:•asks the user to enter the name of a file containing a system of equations•extracts the necessary info from that file and solves the system using numpy•prints the solution to the console in a simple but readable wayPage 2
Department of Computer Science176 Thorvaldson Building110 Science Place, Saskatoon, SK, S7N 5C9, CanadaTelephine: (306) 966-4886, Facimile: (306) 966-4884CMPT 141Fall 2024Introduction to Computer ScienceEquation file formatThe systems of equations will be given in files similar to the provided examples. You can count on thefollowing simplifying guarantees concerning that file format:•Each line of the file will be a single equation•All of the variables and their coefficients will be on the left hand of the equal sign•All of the variables in each equation will be the same, and in the same order•Every equation will include every variable (using a coefficient of 0 if needed)•All of the constants and coefficients will be integers (not floats)•The variables will be joined exclusively with + signs (the coefficients themselves may be negative)•The first character of each variable will always be an alphabetic letterYou will find the provided equation files match these rules, and your program should work on any otherfile that also follows these rules.Problem DecompositionWrite3 separate functionsthat will divide the overall work for this problem, and that when called in se-quence, will extract the info you need from the equations file in the format required by numpy. We’ll de-scribe those functions here.Note that this is NOT the only way to solve this problem; it’s exposing you to just ONE reasonable way todecompose this problem into manageable chunks.Function 1: Get the equationsWrite a function that accepts thefile namewhere the equations are scored, and returns TWO separatelists. The first list should be a list of strings, where each string is one of the equations (i.e. everything upto the equal sign). The second list should be a list of integers of all the constants (i.e. all the numbers onthe right hand sign of the equal sign). For example, forsystem1.txt, the lists returned from this functionshould look like this:[’2x+y+3z’,’5x+3y+z’,’x+7y+12z’][9,15,0]Function 2: Get the variable namesWrite a function that accepts alist of equations(like the list produced by function 1) and returns a list ofall the variable names from the system (you’ll need this simply to print out the solution a little more nicelyat the end). For example, forsystem1.txt, the list returned should look like this:[’x’,’y’,’z’]Function 3: Get the coefficientsWrite a function that accepts alist of equations(like the list produced by function 1) and returns a list-of-lists of integers, where each sublist contains all the coefficients of a SINGLE equation. For example, forsystem1.txt, the list returned should look like this:[[2,1,3],[5,3,1],[1,7,12]]Page 3
Department of Computer Science176 Thorvaldson Building110 Science Place, Saskatoon, SK, S7N 5C9, CanadaTelephine: (306) 966-4886, Facimile: (306) 966-4884CMPT 141Fall 2024Introduction to Computer ScienceMain ProgramIf all three of your functions are working, the main part of your program will be very simple. It only needsto ask the user for the file name, call the three functions in sequence, feed the resulting lists into the linearsolver from numpy, and then use a simple loop of some kind to nicely print out the solution to the system.Sample RunThe overall output of your program might look something like this (except we’ve replaced the actual solu-tion with question marks, so as not to spoil the answer that you’re supposed to compute by hand!):Enterequationsystemfilenameforsolving:system1.txtSolutionforequationsfromsystem1.txt---------x=?.????y=?.????z=?.????What to Hand In(a) A document entitleda7q1_pt1.txt(or .pdf or .png) showing your hand solution for part 1(b) A python programa7q1_pt2.pywith your tiny program for part 2(c) A python programa7q1.pycontaining your program for part 3Evaluation•3 marks for a correct and readable hand solution for part 1•1 mark for the simple hard-coded solution from part 2•3 marks for correctness of results from part 3•3 marks for function design matching the specificationPage 4
Department of Computer Science176 Thorvaldson Building110 Science Place, Saskatoon, SK, S7N 5C9, CanadaTelephine: (306) 966-4886, Facimile: (306) 966-4884CMPT 141Fall 2024Introduction to Computer ScienceQuestion 2 (3 points):All programs that you submit for this assignment will be assessed with regard to theirstyle and readability.Make sure that all of your code:•includes your name, nsid, and student number as comments•uses informative variable names•makes effective use of formatting and white space•includes adocstringfor allfunction definitionsin the program•for longer programs, uses helpful and concise single-line comments where appropriateWhat to Hand InThere is nothing to hand in for this question. It’s simply describing how the rest of your work will be evalu-ated with regard to style and readability. It is possible to earn these marks even if you don’t hand in everyother question in this assignment, but you must hand in enough work such that your style and readabilitycan be adequately assessed.Evaluation•3 marks for consistently following the principles listed abovePage 5
Department of Computer Science176 Thorvaldson Building110 Science Place, Saskatoon, SK, S7N 5C9, CanadaTelephine: (306) 966-4886, Facimile: (306) 966-4884CMPT 141Fall 2024Introduction to Computer ScienceQuestion 3 (2 points):In your submission for this assignment, you have an opportunity to earn something we’ll call "the wowfactor". To earn the wow factor, you must do something creative that goes beyond the expectations laidout in the assignment. This could be an extra feature for one of the previous questions, or it could be anextra little program that you submit that builds on the skills used in the assignment.You should not aim to do a lot of work for this, but should instead demonstrate in a simple and effectiveway the depth of your understanding. In short, take ownership of your work and "impress us".Telling you exactly what to do to earn "the wow factor" would defeat the entire purpose, but here are somevery general ideas.•improve the aesthetic appeal of your program(s)•improve the user-friendliness of your program(s)•remove a simplifying assumption and handle the resulting added complexity•compare two different ways of doing the same task, and submitting data/analysis on which was better•just doing something generally coolOne quick warning: using fancy extra code libraries in order to AVOID a key learning objective from theassignment is not impressive, it’s actually anti-impressive. Focus instead on solving problems using simpleclean foundational programming skills. Using extra libraries is fine if they let you do something BEYONDwhat the assignment asked, but not if they’re replacing a core assigned task.What to Hand InA plain text file calledwow.txtdescribing what you did that you think merits the wow factor. One or twosentences is enough. If you create any additional code files, hand those in too.Evaluation•2 marks for something impressivePage 6