C语言loops基础程序作写代写、writing a C program

日期：2018-04-30 01:35

In this project you will demonstrate your understanding of loops and if statements by writing a program

that sequentially processes a file of text data. You are also expected to make use of functions (Chapters

5 and 6) and arrays (Chapter 7, covered in lectures in Weeks 6 and 7). The sample solution that will be

provided to you will also make use of structures (Chapter 8), and you may do likewise if you wish. But

there is no requirement for you to make use of struct types, and they will not have been covered in

lectures before the due date.

Sequential Data

Scientific and engineering datasets are often stored in text files using comma separated values (.csv

format) or tab separated values (.tsv format), usually with a one- or two-line header describing the

contents of the columns.

The data file used in this project was generated by the City of Melbourne, and uses .tsv format to

record pedestrians as measured by counting devices at a number of locations around the CBD1

. That data

file was then edited to make the test files provided on the LMS. In particular, some of the columns were

removed, some of the columns were reformatted, the hourly counts were aggregated into daily counts,

and three recording stations were extracted into separate files, with the rest of the recording stations

discarded. Smaller subsets of those three data files were also then prepared, see the LMS and Assignment

to a full set of data files. The first few and last two lines of the file pedestrians-melbcent-full.tsv

are:

# Melbourne Central Daily Pedestrian Counts

# yyyy mm dd day daycount

2009 06 01 2 22663

2009 06 02 3 22960

2009 06 03 4 23618

...

2018 02 27 3 33722

2018 02 28 4 33164

There will always be two heading lines in all input files, and then rows of five values separated by

“tab” characters (’\t’ in C). Once the first two lines have been bypassed, each data line can be read

using scanf("%d%d%d%d%d",...). The number in the fifth column is the pedestrian count for the day

indicated by the dd/mm/yyyy date, with the fourth field, day, indicating the day of the week, numbered

from Sunday to Saturday as integers 1 to 7 respectively. You can open these data files using jEdit if

you wish to view them, and they can also be manipulated using Excel.

Stage 1 – Control of Reading and Printing (marks up to 4/10)

Your first program should read the entire input dataset into a collection of five parallel arrays (or, if you

are adventurous, an array of struct), counting the data rows as they are read. The two heading lines

should be discarded and not processed in any way.

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See http://go.unimelb.edu.au/sht6 for a link through to the source dataset, which was accessed from https:

//data.melbourne.vic.gov.au on 28 March 2018.

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Once the entire dataset is in memory, your program should print the first and last of the input records,

and the total number of data lines that were read. The output from your program for this stage for file

pedestrians-melbcent-full.tsv must be:

mac: myass1 < pedestrians-melbcent-full.tsv

S1: total data lines = 3067 days

S1: first data line = 01/06/2009, 22663 people counted

S1: last data line = 28/02/2018, 33164 people counted

mac:

Note that the input is to be read from stdin in the usual manner, via “<” input redirection at the shell

level; and that you should not try and make use of the file manipulation functions described in Chapter 11.

You may (and should) assume that at most 10,000 days will be covered by the input data. Note that

some of the marking process will be automatic, and you should seek to exactly reproduce these three

output lines. Further examples can be found on the FAQ page linked from the LMS.

Stage 2 – Computing Stuff (marks up to 6/10)

Now add further functionality to your program so that it computes the number of entries there would be

in the given date range if every day had a corresponding line in the data file. For the same data file, these

additional lines should appear in your program’s output:

S2: range spanned = 3195 days

S2: coverage ratio = 96.0%

The range spanned is to total number of days (including the two endpoints) in the date range that you

reported in Stage 1, and the coverage ratio is the percentage of dates in this range for which the data

file contains pedestrian count records. In this example, there are 3195 days between 1 June 2009 and 28

February 2018 (inclusive), and 3067/3195 is 96.0%. You can check date range calculations using Excel.

Note that code should be shared between the stages through the use of functions wherever it is

possible to do so. In particular, there shouldn’t be long (or even short) stretches of repeated or similar

code appearing in different places in your program. Functions should also be used to break up long runs

of code, to make them more understandable, even if those functions are only called once. As a general

rule of thumb, functions shouldn’t be longer than a single screen in the editor. If they are, break that code

up further into smaller functions.

You may assume that the data records are presented in strictly increasing date order, and that you

are not required to sort them. Note also that there will be no duplicate dates. On the other hand, you

must not assume that there will be any particular year range in the input data, and must not assume that

the months and dates will be exhaustive (there may be missing days, missing months and maybe even

missing years).

Stage 3 – Make Summary Report (marks up to 8/10)

Modify your program further so that it also generates a “by the month” listing showing the average

observed daily pedestrian numbers for each month for which there is any data provided in the input

listing. Months that have no daily data provided should not be included in the output. For this stage, the

required output for the test file pedestrians-melbcent-p100.tsv (with a total of 98 data lines) is:

S3: 06/2009 28/30 days covered, average count = 24.8k

S3: 07/2009 31/31 days covered, average count = 26.7k

S3: 08/2009 31/31 days covered, average count = 26.7k

S3: 09/2009 8/30 days covered, average count = 24.4k

where “k” means “thousands”. See the LMS for the full output associated with the test files.

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Stage 4 – Find the Trend (marks up to 10/10)

The Melbourne City Council is concerned that pedestrian traffic is increasing, and that the footpaths are

becoming congested. To help them understand the growth rate over the sample period, further modify

your program so that the input data is split into NGRPS near-equal sized (in terms of data records in the

input file) groups of consecutive data lines from the input, where you should assume that NGRPS is to

be three at present. The group sizes should be computed so that they differ by at most one from each

other, and so that each input data line is in exactly one of the groups. There are several examples of the

required output linked from the FAQ page.

The average number of pedestrians for each day of the week for each of the groups should then be

computed, and plotted as a simple bar chart, to highlight any variations over the days of the week and

over the NGRPS groups. For the data file pedestrians-melbcent-full.tsv the additional output from

your program should be:

S4: group 0 data, 01/06/2009 to 20/03/2012, 1022 data records

S4: group 1 data, 21/03/2012 to 08/01/2015, 1022 data records

S4: group 2 data, 09/01/2015 to 28/02/2018, 1023 data records

S4: Sun, g0 = 22.2k |**********************

S4: Sun, g1 = 27.6k |****************************

S4: Sun, g2 = 28.8k |*****************************

S4: Mon, g0 = 24.4k |************************

S4: Mon, g1 = 27.6k |****************************

S4: Mon, g2 = 28.3k |****************************

S4: Tue, g0 = 24.9k |*************************

S4: Tue, g1 = 28.6k |*****************************

S4: Tue, g2 = 29.3k |*****************************

and so on, covering the other four days too, see the LMS for full output, where each ’*’ represents

(correctly rounded off) one thousand people. Note that NGRPS should be a #define in your program,

and that you should test your program using a range of values to ensure that the right output is produced.

Modifications to the Specification

There are bound to be areas where this specification needs clarification or correction. Refer to the

for updates to these instructions. There is already a range of information provided there that you need to

be aware of, with more to follow.

Real Software

If you want to explore a much more sophisticated analysis tool for this pedestrian data, go via the redirection

The Boring Stuff...

This project is worth 10% of your final mark. A rubric explaining the marking expectations will be

provided on the FAQ page.

You need to submit your program for assessment; detailed instructions on how to do that will be

posted on the LMS once submissions are opened. Submission will not be done via the LMS; instead you

will need to log in to a Unix server and submit your files to a software system known as submit. You can

(and should) use submit both early and often – to get used to the way it works, and also to check that

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your program compiles correctly on our test system, which has some different characteristics to the lab

machines. Failure to follow this simple advice is highly likely to result in tears. Only the last submission

that you make before the deadline will be marked.

You may discuss your work during your workshop, and with others in the class, but what gets typed

into your program must be individual work, not copied from anyone else. So, do not give hard copy

or soft copy of your work to anyone else; do not “lend” your “Uni backup” memory stick to others

for any reason at all; and do not ask others to give you their programs “just so that I can take a look

and get some ideas, I won’t copy, honest”. The best way to help your friends in this regard is to say a

very firm “no” when they ask for a copy of, or to see, your program, pointing out that your “no”, and

their acceptance of that decision, is the only thing that will preserve your friendship. A sophisticated

program that undertakes deep structural analysis of C code identifying regions of similarity will be run

over all submissions in “compare every pair” mode. Students whose programs are so identified will be

referred to the Student Center for possible disciplinary action without further warning. This message is

the warning. Note also

that solicitation of solutions via posts to online forums, whether or not there is payment involved, is also

taken very seriously. In the past students have had their enrolment terminated for such behavior.

Deadline: Programs not submitted by 10:00am on Monday 30 30 April will lose penalty marks

at the rate of two marks per day or part day late. Students seeking extensions for medical or other

“outside my control” reasons should email ammoffat@unimelb.edu.au as soon as possible after those

circumstances arise. If you attend a GP or other health care professional as a result of illness, be sure

to take a Health Professional Report form with you (get it from the Special Consideration section of the

Student Portal), you will need this form to be filled out if your illness develops in to something that later

requires a Special Consideration application to be lodged. You should scan the HPR form and send it in

connection with any non-Special Consideration assignment extension requests.

Marks and a sample solution will be available on the LMS by Monday 14 May.

And remember, programming is fun!