Alternative to the sort function

Question

Charles Perkins 2022-5-3

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1710405-alternative-to-the-sort-function

评论： Steven Lord 2022-5-7

采纳的回答： Walter Roberson

Looking for an alternative way to sort values in either decending or acsending order without using the sort function

2 个评论
显示无隐藏无

Walter Roberson 2022-5-3

Why? Your reason for not using sort() will influence the recommendations.

Charles Perkins 2022-5-3

I am in a beginner programming class (only a couple weeks in) one of the homework tasks asks to create a program that sorts user inputted numbers in ascending order without the sort function. I am struggling with this.

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Walter Roberson 2022-5-3

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1710405-alternative-to-the-sort-function#answer_956010

https://www.mathworks.com/matlabcentral/answers/49226-how-to-apply-a-mean-filter-for-3x3#comment_2111490 and look for bogosort() source code there.

You would have to adapt it slightly to give a choice of ascending or descending, and you would have to adapt for non-vectors.

7 个评论
显示 5更早的评论隐藏 5更早的评论

Charles Perkins 2022-5-6

I've got the sorting part of the code working, (thankyou for your help), I am now stuggling with putting the using input into a vector without a predetermined length. The code i've got will only sort the last number entered into order. What I have is below

**Command Window**

Input a number: 5

Input a number: 4

Input a number: 5

Input a number:

Input a number: 6

Input a number: 54

Input a number: 0

Converting input into ascending order

The input numbers to be arranged:

0

The ascending matrix is

0

>>

**Editor**

% clear comand window

clc;

clear;

% Prompt input of numbers to be arranged from user until input = <= 0 is entered

x = [];

while 1

x = input('Input a number: ');

if x <= 0; break; end

end

disp('Converting input into ascending order ')

% The vector of numbers

disp('The input numbers to be arranged:')

A=[x];

disp(A)

% Number of entries, n

n=length(A);

% making (n-1) passes

for j=1:1:n-1

% comparing each number with the next and swapping

for i=1:1:n-1

if A(i)>A(i+1);

% temp is a variable where the numbers are kept

% temporarily for the switch

temp=A(i);

A(i)=A(i+1);

A(i+1)=temp;

end

disp(' ')

disp ('The ascending matrix is')

disp(A)

Charles Perkins 2022-5-7

Mate you are a legend, thank you heaps. This is what I ended up with, not sure if it was quite what you were getting at but definitely based off your suggestions.

clc;

clear;

count = 0;

values = [] ;

while true

value = input('Input numbers to be arranged') ;

if value <= 0

break;

end

count= count +1

values(count) = value;

end

disp('Converting input into ascending order ')

% The vector of numbers

disp('The input numbers to be arranged:')

A=[values];

disp(A)

% Number of entries, n

n=length(A);

% making (n-1) passes

for j=1:1:n-1

% comparing each number with the next and swapping

for i=1:1:n-1

if A(i)>A(i+1);

% temp is a variable where the numbers are kept

% temporarily for the switch

temp=A(i);

A(i)=A(i+1);

A(i+1)=temp;

end

disp(' ')

disp ('The ascending matrix is')

disp(A)

Steven Lord 2022-5-7

在 MATLAB Online 中打开

One suggestion that will eliminate the need for your count variable: the end function when used as an index refers to the position of the last element / row / column / etc. in an array. You can use this in assignment or referencing statements, including using it in some simple mathematical expressions. Let's start off with an empty array x.

x = []
x =

     []

We can assign to an element one past the end to make the vector longer:

x(end+1) = 1
x = 1

We can do that again.

x(end+1) = 3
x = 1×2
     1     3

Let's reset the last value.

x(end) = 42
x = 1×2
     1    42

In this next statement, x has 2 elements so end+2 is 4. Therefore the next command sets x(4) to 10 with x(3) filling in with the default value of 0.

x(end+2) = 10
x = 1×4
     1    42     0    10

We don't have to add to end, we could also subtract. x has 4 elements so end-3 is 1 and y is x(1).

y = x(end-3)
y = 1

请先登录，再进行评论。

Alternative to the sort function

2 个评论
显示无隐藏无

采纳的回答

7 个评论
显示 5更早的评论隐藏 5更早的评论

更多回答（0 个）

另请参阅

类别

标签

Community Treasure Hunt

Alternative to the sort function

2 个评论 显示 无隐藏 无

采纳的回答

7 个评论 显示 5更早的评论隐藏 5更早的评论

更多回答（0 个）

另请参阅

类别

标签

Community Treasure Hunt

2 个评论
显示无隐藏无

7 个评论
显示 5更早的评论隐藏 5更早的评论