EEE125 Programming in ‘C’ Course: program writing assignmentAt the first lecture I discussed the make-up of this course and explained that the course would be assessed bymeans of a MOLE exam (worth 30% of the available marks) that has already taken place, this C assignment task(also worth 30%), then in semester 2 some Matlab in-class assessments (worth 10%) and a final in-class Cprogram writing exam (worth 30%).For this assessed assignment you are asked to write a program in ‘C’ to carry out the particular taskdetailed here.1 Administrative detailsYour program must be handed in via MOLE. The hand-in date for this exercise is 11.59pm on Tuesday 11thDecember. You can hand your work in there anytime between now and that date. Late submission will result in a deduction of 5% of the total mark awarded for each working day after thesubmission date, this is Faculty policy. (Working days – Monday to Friday - include working days withinstandard vacation times). The only exceptions to this will usually be where illness or other seriousextenuating circumstances have meant missing the hand-in date (medical evidence will often be needed tosustain this exception). In such circumstances you MUST submit an Extenuating Circumstances form (nota self-certification form), available from www.sheffield.ac.uk/ssid/forms/circs, (before completing such aform make sure you read the explanatory notes here first: http://www.sheffield.ac.uk/ssid/forms/circsnotes)hand the form in to the department Student Support Office (Suite 27, level 1, 3 Solly Street building) oremail directly to me. If you believe you have good reason to ask for an extension to this hand-in date, you may discuss thecircumstances with Peter Judd and, at his discretion, a later hand-in date may be negotiated. (But please do thediscussing well in advance of the original hand-in date expiring). Please note: being disorganised or lazy andso failing to meet the hand-in date by simply leaving tackling the exercise until its too late is not a “goodreason” and will not normally result in an extension of the hand-in date!________________________________________________________________________________________2 What your program should doElsewhere in your studies you may have heard of the “Least Squares” method often used to generate a “best fit” straightline through a set of data plotted on a graph (where a straight line relationship is expected to exist). The Least Squaresmethod is very useful when working with data derived from experiments and indeed it may well be a technique of use toyou elsewhere in course work.The aim of this assessed exercise is: for you to write a program in C that uses the least squares technique to allow a userto input a set of data value and to compute and output as results the gradient (m) and offset (c) of the “best fit” straight linethrough that entered set of data. You do not have need understand the underlying mathematics (though it would help) insteadall you need to do is correctly implement the formulae given in this assignment sheet.2.1 The Least Squares formulae neededConsider you have a set of data comprising pairs of measurements of two related variables: ‘x’ & ‘y’. You believethe relationship between these variables can be expressed as a straight line, using the standard straight lineequation (where y is the dependent variable and x is the independent variable, m is the gradient of the line - thatis the rate of change of y with respect to x - and c is the intercept (or ‘offset’) of the line with the y axis – that isthe value of y when x is zero). Here is the standard straight line equation:y = m. x + c U:\C\c-18-19\Tutorial\Assessed_Exercise_No_1\Assess-1-2018-19.docx - 2 - (? Peter Judd/University of Sheffield 98-18)Look at the example graph shown below. Pairs of x, y data have been plotted (the little ‘+’ marks) and a best fitstraight line drawn through them (the dotted line). The gradient of the “best fit” straight line is ‘m’ and theintercept (offset) of that line with the y axis from the origin of the graph is ‘c’.From theory we can obtain the equations needed todraw a best fit straight line through such a set of datausing “Least Squares” as our technique.Consider we have a set of data samples where values of‘y’ have been measured for a range of different valuesof ‘x’. Consider we have taken ‘N’ samples (i.e. pairsof x and y data of the form: [x1 y1] [x2 y2] [x3 y3] … [xNyN]). Then using this notation we can write thefollowing equations:The least squares equation for the gradient of the ‘best fit’ line ‘m’ is:The least squares equation for the offset of the ‘best fit’ line ‘c’ is:When interpreting these formulae you might like to be reminded that:Nnn Nx x x x x x11 2 3 4....Although these formulae may initially look daunting, note that they contain some common terms, for examplenote how many timesNnnx1appears in the formulas above. By identifying such common terms you can perhapssave effort by calculating them only once and use the results when those terms appear in later equations or writingone function to do this and use it each time it’s needed.Y AxisX Axis00offset - cValue of XValue of YBest fitstraight line ofgradient mU:\C\c-18-19\Tutorial\Assessed_Exercise_No_1\Assess-1-2018-19.docx - 3 - (? Peter Judd/University of Sheffield 98-18)2.2 How the program should appear to the user – the Requirements.Reminder, the aim of this assessed exercise is for you to write a program that will allow the user to enter a setof data (in the form of x, y pairs) and then uses the least squares technique to calculate and display the gradient(m) and offset (c) of the “best fit” straight line through that set of data.a) The program should begin by briefly announcing its purpose to the user.b) Next it should ask the user how many pairs of data values (sets of x and y) he/she intends to input, onlypermitting the user to choose numbers of pairs in the range from 4 to 20 pairs (that is the user should bepermitted to enter no fewer than 4 pairs and no more than 20 pairs).c) Make sure your program displays clear instructions to the user at each stage so that the user knows exactlywhat the program wants her (or him) to do.d) The program should then ask the user to input the specified number of data value pairs, storing them in suitablevariable(s). Your program should be able to accept values for x and y entered as real numbers. Your programshould accept only positive numbers that are in the range between l000000.0 and 0.000005.e) Next the program should neatly display all the data pairs entered in a tidy way on the screen.f) The program should use the least squares formulae described section 2.1 above to process the set of dataentered and so calculate the values for ‘m’ and ‘c’ for the ‘best fit’ straight line through that set of data.g) The program should then neatly display the values of ‘m’ and ‘c’ that it has calculated.h) The program should then ask the user if he/she would like to repeat the program, interpret their reply, and, iftheir answer is yes then the program should repeat again all steps from step b) onwards.Please note: When designing you program: be careful to ensure that it makes efficient use of variable space by choosingsuitable types for your variables that do not waste memory unnecessarily. Don’t just assume this programwill be compiled to run on a PC with the Dev-C compiler, make sure you use the smallest ‘C’ type variablesnecessary according to the minimum sizes I gave for the standard C types in the lectures. Also makeappropriate use of the various flow-control statements C has to offer to build loops where they would behelpful. I want you to divide your program up into separate functions. Programs that consist of everything inside thesingle function main only will earn far fewer marks than programs that are divided into more than onefunction.2.3 A sample data set to use for testingHere is some sample data upon which you might like to test your program:First a simple set (you could try plotting it as a graph and estimating m and c by hand):X Y1.1 2.92.0 4.12.9 5.04.1 5.94.9 7.16.0 8.0The results are: Gradient of best fit straight line m = 1.025 approx. with and a y intercept at c = 1.911 approx. U:\C\c-18-19\Tutorial\Assessed_Exercise_No_1\Assess-1-2018-19.docx - 4 - (? Peter Judd/University of Sheffield 98-18)Now a more complex set:X Y103 65.92 x 103 1223 x 103 1874 x 103 2565 x 103 3146 x 103 3587 x 103 4578 x 103 4829 x 103 582104 635The results are: Gradient of best fit straight line m = 0.0634 and a y intercept c at -2.907.________________________________________________________________________________________2.4 Some helpful hints? Your program must be written in ‘C’ and not ‘C++’. (I teach ‘C’ in my lectures, not C++, so sticking totechniques I have taught will mean you will be OK). Make sure you save your file with a ‘.c’ filenameextension NOT ‘.cpp’. When using Dev-C make sure when saving your file that the “Save File” dialoguehas the “Save as type” drop-down menu set for “C source files (*.c)”. By the time this sheet is handed out you will have already covered, in lectures and tutorials, all the materialnecessary to allow you to write a suitable program. However, future lectures and background reading of yourown may be of additional help.Make your program code as easy to read (by a human) as possible. For example partition it (in other wordsbreak it up) by making your own functions. (Programs that consist of everything inside the single functionmain only will earn fewer marks than programs that are divided into more than one function). (See my examplesolution to Lab 5 question 4 file TUT5Q4-4.c in the EEE125 MOLE course, in the ‘Lab Classes’ section, inthe ‘Lab Class Downloads’ folder and finally in the ‘Lab Sheet 5 – Downloads’ showing use of functions).Use well-chosen identifiers for function names and variable names so that the purpose of a particularfunction or variable is hinted by its name. Make sure the program is well commented (i.e. using /* */ marks) so that the purpose of each part is clear.These comments should be concise. Note: there is no need to use comments to explain how a particular ‘C’construct works, you can assume the reader understands the ‘C’ language itself (e.g. you don’t need to explainhow a ‘for’ loop works as such). However you should add comments to explain what your program aims toachieve with particular ‘C’ constructs where it isnt immediately obvious (e.g. explain what useful task aparticular ‘for’ loop is performing for you in your particular program). This is an important skill needed byprogrammers to ensure their program code is ‘readable’ and ‘understandable’ by others who may have causeto examin代做EEE125作业、代写C/C++编程作业、代做program writing作业、代做C/C++语言作业 代写留学生e it or modify it later. I have given clear guidance in the lectures about how to lay out a program andhow to add comments – check your lecture slides to see what I said.? Dont forget: planning your program thoroughly on paper first is by far the most effective way of quicklywriting a good program. Dont rush to coding at the PC too soon. Start by breaking the task down intomanageable portions, then plan the sequence of events for each portion with flow-charts and pseudo code etc.Flow-charts in particular will help you identify the appropriate flow control statements (while, do..while,for, if etc.) to choose. Test the output from your program by using various sets of data. You can generate your own test data quiteeasily. Use a calculator or a spreadsheet to help verify your results. Dont forget to check your programsbehaviour with illegal data (i.e. data outside the range allowed for input), does it behave appropriately?U:\C\c-18-19\Tutorial\Assessed_Exercise_No_1\Assess-1-2018-19.docx - 5 - (? Peter Judd/University of Sheffield 98-18) Dont forget, “divide and conquer” is a wise approach. Break the task down into manageable portions andtackle them one at a time, dont try and code up the whole program in one go only to find it doesnt work. Thetask of finding a fault (or more likely many faults) in a large program is like looking for a needle in a haystack- make sure you have only a small haystack to search! Start off with a small program which only does thefirst few steps of the task, get that working first. Next add a bit more to your program and get that workingtoo. Continue in this way until the program can carry out the complete task Above all, be sure to hand something in by the hand-in date. If you examine my marking scheme carefully(see later) you will see that only a small proportion of the marks are available for accuracy of results etc.there are many more marks available for other aspects of the work I ask for. If you only manage to produce aprogram that asks for, stores and re-displays the input sample data values but does not even attempt to doanything else then I can at least give you some marks for that much (which is better than no marks if you handin nothing!) If you need help:a) Please talk to me or my demonstrators during a timetabled afternoon computer lab. session.b) Be sure to make full use of the C books in the library and the web links provided in our MOLE course.c) If you still need help, email me to make an appointment to sit down with me 1 to 1. When you send suchan email be sure to suggest as many time-slots when you could be available to meet as you can so that Ihave a good chance of finding a mutually convenient meeting time.3 What should you hand in?3.1 The program itself: You should hand you ‘C’ program file itself in via MOLE (see instructions in section 3.2 below) and itshould be in the form of a source file of ‘C’ code (that is the ASCII text file created in the usual way by usingthe Dev-C++ Editor when writing a program and saved with the filename and the file name extension for CSource Files: “leastsq.c”). You MUST name the file “leastsq.c Please use this name only, it helpsme process your work quickly. It must not be called “leastsq.cpp! (*.cpp implies a C++ file and youmust not write in C++!) You MUST write your Registration number into a comment string as the first line of your program likethis:/* My Reg Number: 180113134 */#include …and so on. You are NOT required to include your name. If you choose to write and test your program using a `C compiler other than the Bloodshed Dev-C environmentprovided for you on the Universitys Computer network (as used in the lab. sessions) then I stronglyrecommend that you bring the final version of your source code into the University and check it compiles andruns correctly using the Dec-C compiler on the Universitys Computer network before handing it in. It is thissame Dev-C compiler environment that I will use to compile and test you program in order to assess it!U:\C\c-18-19\Tutorial\Assessed_Exercise_No_1\Assess-1-2018-19.docx - 6 - (? Peter Judd/University of Sheffield 98-18)3.2 Submitting your file:To submit your program via MOLE follow these instructions (follow them carefully as you only get one chanceto submit!):a) You only have one chance to submit your file, once submitted you cannot change it, so be sure you arefinished and have chosen the correct file to submit and attach it correctly.b) Once you have finished your C source file and you are happy that it is ready to submit it, open a webbrowser and either login in to MOLE via MUSE or log in to MOLE directly as follows:http://vista.shef.ac.uk/ and log in usual wayc) On the “EEE125 Programming” course home page look for the ‘Assessment and Feedback’ section inthe left-hand menu.d) In the ‘Assessment and Feedback’ section of this left-hand menu you should see a heading called‘Assessment’. Click on this.e) You should now see an item titled “C Programming Course, Assessed Exercise No. 1”, make sure youclick on this title.f) Scroll down to section “Assignment Submission”. DO NOT use the Create Submission button. Lookbelow and you will see a line beginning “Attach file” and a button marked “Browse My Computer”Click on this. A file browser window should now open.g) In the file browser window navigate to your folder and select your ‘C’ source file leastsq.c in theconventional way. (Make absolutely sure you are selecting the C source file - the one you typed – notany of the other associated files the compiler generates when you compile and run your program). To dothis, look at the icon displayed beside the file name, make sure you pick the file with the icon showing asmall blue ‘.c’ in the corner. Double click on your leastsq.c file to attach it. It should now appear ina list of “Attached files”.h) Once you are sure you have attached your leastsq.c file then scroll to the bottom of the page and youshould see the Submit button on the right hand side, click this button to submit your work. Note: Youmust NOT write anything in the Add Comments box (I will not read anything placed here).U:\C\c-18-19\Tutorial\Assessed_Exercise_No_1\Assess-1-2018-19.docx - 7 - (? Peter Judd/University of Sheffield 98-18)3.3 Marking SchemeHere is the marking scheme I will use to mark your work. Initially, as you can see, I will mark out of 100, “fullmarks” would be 100%.Aspect Comment MarkOverallProgramDesignDoes the program try to meet the specification laid out in thissheet? Is it designed to do all the things asked for?20Choice ofVariablesHave variables been created using appropriate types and do theymake efficient use of storage space?5Quality of `CcodeHave the many useful ‘C’ language features discussed inlectures and tutorials been exploited? Are the ‘C’ constructsused appropriately?10Readability ofcodeIs the programs purpose easily understood from the way itsstructured e.g. does it have an appropriate hierarchical form(exploiting functions?). Is it well (concisely and clearly)commented? Have sensible, self explanatory, identifiers beenchosen for function names and variable names?5Use ofFunctionsHave user functions other than main been written at all? Arethey used sensibly? Is the choice of return types and parameterssensible?20Compile &RunDoes the program compile without errors or serious warnings?Does it run without crashing etc?10Accuracy ofresultsAre the results it produces correct? 20User interface Does the user interface clearly inform the user what she or hemust do at each stage? Are the outputs presented clearly and inan appropriate fashion?10 Total 1004 Unfair MeansThe basic principle underlying assessed work is that the work submitted for assessment must be entirelyyour own. No one objects to you discussing the principles of C programming in general with others, but:plagiarism and collusion are not allowed. You must not discuss the details of how to do this exercise with anyone other than Peter Judd or one of his programming lab. demonstrators. In the context of this exercise, unfairmeans would include:1 You MUST NOT allow anyone else to write or dictate to you your program, in whole or in part.2 You MUST NOT look at someone else’s program for this exercise or copy from someone else’s work orexchange emails or internet chat messages (MSM, Weibo, Whatsapp, Facebook or similar) with someoneelse which include code from either your program or their program for this exercise. Note: this includes withthe lab. Demonstrators or students in other years.3 Likewise you MUST NOT write program code for, or share program code with, another student on thiscourse or from previous years of study or anyone else.4 You MUST NOT team up with others to write one program (in whole or in part) together, then all hand inprograms containing that same code (in whole or in part).5 You MUST NOT copy portions of code from any sources (that are not of your own creation) such as awebsite or a book or from someone else’s computer, website (even from a website where the language is notEnglish) or memory device. (However: I grant you exceptional permission to copy from any of the U:\C\c-18-19\Tutorial\Assessed_Exercise_No_1\Assess-1-2018-19.docx - 8 - (? Peter Judd/University of Sheffield 98-18)examples of code that I have given to you during this course as lecture or tutorial examples – if you dothis, then attribute the source of those portions of code to me by writing my name in a comment like this /*taken from Peter Judd’s examples */ immediately before and immediately after the codeconcerned.)Remember: the basic principle underlying assessed work such as this is that the work submitted forassessment must be entirely your own. We wish to only give marks for programs written by you alone!If you are in any doubt about what might constitute unfair means in the context of this exercise then pleasediscuss any areas of uncertainty with me. If you experience any problems with this assignment then seek helpfrom me or the demonstrators present during lab. sessions.Please note: I will be using a sophisticated program specially designed to detect plagiarism in a set of ‘C’programs to help me detect evidence of such unfair means in the assessed work that you hand in, so, pleasedont take the risk of copying work, submit only work done by you entirely on you own. Where I suspect unfairmeans to have been used, the department reserves the right to give zero marks to all individuals concernedand/or refer you to the University Discipline Committee and/or place a note in your student record file(We have caught people breaking these recommendations before and done all these things, so do please note thewarning!).Good Luck! Peter Judd转自：http://ass.3daixie.com/2018121327928119.html
