Let's say I have Point[] and I want to sort it circle way (e.g.
2;2.4;1,8;2,8,5 ;4;8,2;7,1;4
The algo for this is:
if ((p[i].X<p[i+1].X & p[i].Y<Avg(p).Y & p[i+1].Y<Avg(p).Y) |
(p[i].X>p[i+1].X & p[i].Y>Avg(p).Y & p[i+1].Y>Avg(p).Y) )
Swap(p[i],p[i+1]);
where Avg(p).Y is the middle (average) of all Y values.
Other words:
First of all all point with Y above the Middle of Ys acsending and then
all point with Y under the Middle of Ys descending
Is there more effecient way to do this except buble sort for 2 axes?
TNX
--
Tamir Khason
You want dot.NET? Just ask:
"Please, www.dotnet.us " 6 8193
Use System.Array.So rt(p, new Class1()) where class1 implements IComparer and place your code in the compare routine.
--
Michael Culley
"Tamir Khason" <ta**********@t con-NOSPAM.co.il> wrote in message news:u1******** ******@TK2MSFTN GP12.phx.gbl... Let's say I have Point[] and I want to sort it circle way (e.g. 2;2.4;1,8;2,8,5 ;4;8,2;7,1;4 The algo for this is: if ((p[i].X<p[i+1].X & p[i].Y<Avg(p).Y & p[i+1].Y<Avg(p).Y) | (p[i].X>p[i+1].X & p[i].Y>Avg(p).Y & p[i+1].Y>Avg(p).Y) ) Swap(p[i],p[i+1]); where Avg(p).Y is the middle (average) of all Y values. Other words: First of all all point with Y above the Middle of Ys acsending and then all point with Y under the Middle of Ys descending
Is there more effecient way to do this except buble sort for 2 axes?
TNX
-- Tamir Khason You want dot.NET? Just ask: "Please, www.dotnet.us "
TNX for response.
Did it at first try, but it works even slower then straight forward
algorithms. Maybe did something wrong?, but prety sure that did not
As far as I nuderstand IComparer did the same old Buble sort, so why it
slower?...
--
Tamir Khason
You want dot.NET? Just ask:
"Please, www.dotnet.us "
"Michael Culley" <mc*****@NOSPAM optushome.com.a u> wrote in message
news:u5******** *****@TK2MSFTNG P12.phx.gbl... Use System.Array.So rt(p, new Class1()) where class1 implements IComparer
and place your code in the compare routine. -- Michael Culley
"Tamir Khason" <ta**********@t con-NOSPAM.co.il> wrote in message
news:u1******** ******@TK2MSFTN GP12.phx.gbl... Let's say I have Point[] and I want to sort it circle way (e.g. 2;2.4;1,8;2,8,5 ;4;8,2;7,1;4 The algo for this is: if ((p[i].X<p[i+1].X & p[i].Y<Avg(p).Y & p[i+1].Y<Avg(p).Y) | (p[i].X>p[i+1].X & p[i].Y>Avg(p).Y & p[i+1].Y>Avg(p).Y) ) Swap(p[i],p[i+1]); where Avg(p).Y is the middle (average) of all Y values. Other words: First of all all point with Y above the Middle of Ys acsending and then all point with Y under the Middle of Ys descending
Is there more effecient way to do this except buble sort for 2 axes?
TNX
-- Tamir Khason You want dot.NET? Just ask: "Please, www.dotnet.us "
"Tamir Khason" <ta**********@t con-NOSPAM.co.il> wrote in message news:uf******** *****@TK2MSFTNG P12.phx.gbl... TNX for response. Did it at first try, but it works even slower then straight forward algorithms. Maybe did something wrong?, but prety sure that did not
Try converting this vb6 code to C#. It should be very quick. http://www.mikesdriveway.com/misc/sort.zip
As far as I understand IComparer did the same old Buble sort, so why it slower?...
I would have thought it would have a better algorithm than bubble. How many times does it call the Compare routine compared to your
bubble sort?
--
Michael Culley
Works your algorithmus?
If I had an array of points to be sorted by distance of origin [0;0], I
would calculate the sum of the square of x and y and sort by this number
Point[] points=....;
System.Collecti on.SortedList sortedList=new
System.Collecti on.SortedList(p oints.Length);
for(int i=0;i<points.Le ngth;i++)
sortedList.Add( points[i].X*points[i].X+points[i].Y*points[i].Y,points[i]);
"Tamir Khason" <ta**********@t con-NOSPAM.co.il> schrieb im Newsbeitrag
news:u1******** ******@TK2MSFTN GP12.phx.gbl... Let's say I have Point[] and I want to sort it circle way (e.g. 2;2.4;1,8;2,8,5 ;4;8,2;7,1;4 The algo for this is: if ((p[i].X<p[i+1].X & p[i].Y<Avg(p).Y & p[i+1].Y<Avg(p).Y) | (p[i].X>p[i+1].X & p[i].Y>Avg(p).Y & p[i+1].Y>Avg(p).Y) ) Swap(p[i],p[i+1]); where Avg(p).Y is the middle (average) of all Y values. Other words: First of all all point with Y above the Middle of Ys acsending and then all point with Y under the Middle of Ys descending
Is there more effecient way to do this except buble sort for 2 axes?
TNX
-- Tamir Khason You want dot.NET? Just ask: "Please, www.dotnet.us "
The documentation says that Array.Sort(myAr ray, IComparerObject ) uses a
quicksort:
"This method uses the QuickSort algorithm. This is an O(n ^2) operation,
where n is the number of elements to sort, with an average of ?(n log n)."
"Michael Culley" <mc*****@NOSPAM optushome.com.a u> wrote in message
news:eZ******** ********@TK2MSF TNGP10.phx.gbl. .. "Tamir Khason" <ta**********@t con-NOSPAM.co.il> wrote in message
news:uf******** *****@TK2MSFTNG P12.phx.gbl... TNX for response. Did it at first try, but it works even slower then straight forward algorithms. Maybe did something wrong?, but prety sure that did not
Try converting this vb6 code to C#. It should be very quick.
http://www.mikesdriveway.com/misc/sort.zip
As far as I understand IComparer did the same old Buble sort, so why it slower?...
I would have thought it would have a better algorithm than bubble. How
many times does it call the Compare routine compared to your bubble sort?
-- Michael Culley
"Dan" <da*@dontspamme .com> wrote in message news:eE******** ******@tk2msftn gp13.phx.gbl... The documentation says that Array.Sort(myAr ray, IComparerObject ) uses a quicksort:
"This method uses the QuickSort algorithm. This is an O(n ^2) operation, where n is the number of elements to sort, with an average of ?(n log n)."
I tested the ArrayList sort and compared it to my* sort. I thought mine was fast but the arraylist sort was significantly faster
(3.6 times faster). The bubble sort took huge amounts of time, I stopped it before it finished. If the op is getting poor results it
must be because their algorithm is slow. It could also be slow because of incorrect data being returned , eg if you tell it A > B
and B > A it is bound to get confused.
Results for sort of 100,000 items (Time (ms), Comparison Count):
My Sort 2895, 4,066,741
Arraylist sort 771, 2,223,288
Bubble Sort 2,500,000, 5,000,000,000
The time for the bubble sort was estimated cause I got sick of waiting :-)
*It's not really my sort, I pinched it from a website somewhere, all I did was package it into a reusable class. :-)
--
Michael Culley This thread has been closed and replies have been disabled. Please start a new discussion. Similar topics |
by: Gram |
last post by:
Hello,
Can anyone help out with a bubble sort for strings using ASP? I have a text
file of words id like to sort and count.
Thanks in advance for any help.
Gram.
|
by: Elijah Bailey |
last post by:
I want to sort a set of records using STL's sort() function,
but dont see an easy way to do it.
I have a
char *data;
which has size mn bytes where m is size of the record and
n is the number of records. Both these numbers are known
|
by: PCHOME |
last post by:
Hi!
I have questions about qsort( ). Is anyone be willing to help?
I use the following struct:
struct Struct_A{
double value;
...
} *AA, **pAA;
|
by: Daniel Weinand |
last post by:
hello ng,
i have a problem and a imho an insufficient method of solution.
strings should be sorted by specific text pattern and dispayed
in groups. the strings are stored in a db and have the following layout:
1.0.0.0
1.1.0.0
1.1.1.0
1.1.2.0
|
by: hoopsho |
last post by:
Hi Everyone,
I am trying to write a program that does a few things very fast
and with efficient use of memory...
a) I need to parse a space-delimited file that is really large,
upwards fo a million lines.
b) I need to store the contents into a unique hash.
c) I need to then sort the data on a specific field.
d) I need to pull out certain fields and report them to the user.
| |
by: yeti349 |
last post by:
Hi, I'm using the following code to retrieve data from an xml file and
populate a javascript array. The data is then displayed in html table
form. I would like to then be able to sort by each column. Once the
array elements are split, what is the best way to sort them? Thank you.
//populate data object with data from xml file.
//Data is a comma delimited list of values
var jsData = new Array();
jsData = {lib: "#field...
|
by: Protoman |
last post by:
Why doesn't my double bubble sort algorithm sort; it just spits the
numbers out, int the exact same order that I inputted them.
Code:
void swap(int& i,int& j)
{
i^=j;
j^=i;
i^=j;
|
by: SimeonArgus |
last post by:
I need to sort a list of points, so I've considered using an
IComparable implementation. Should be easy, right? But I need to know
two things in the CompareTo function, not one.
Test1: I need to know the distance in space from the "current point"
to the point sent in. This is what the current IComparable interfeace
gives me.
Test2 : I also need to know the distance in space from the "previous
point" to the point being sent in. HERE is...
|
by: kimt |
last post by:
Hello, I am currently writing an application that involves many (>
1000) points on a (x,y) plane. I am using a struct to contain the
position information, and I have the structs contained in a STL
vector. Given a target coordinate (x,y)_t, I would like to be able to
cycle through the vector of points in order to obtain the closest
point. What would be the most efficient way to implement this?
I have considered keeping the vector sorted...
|
by: marktang |
last post by:
ONU (Optical Network Unit) is one of the key components for providing high-speed Internet services. Its primary function is to act as an endpoint device located at the user's premises. However, people are often confused as to whether an ONU can Work As a Router. In this blog post, we’ll explore What is ONU, What Is Router, ONU & Router’s main usage, and What is the difference between ONU and Router. Let’s take a closer look !
Part I. Meaning of...
|
by: Oralloy |
last post by:
Hello folks,
I am unable to find appropriate documentation on the type promotion of bit-fields when using the generalised comparison operator "<=>".
The problem is that using the GNU compilers, it seems that the internal comparison operator "<=>" tries to promote arguments from unsigned to signed.
This is as boiled down as I can make it.
Here is my compilation command:
g++-12 -std=c++20 -Wnarrowing bit_field.cpp
Here is the code in...
| |
by: jinu1996 |
last post by:
In today's digital age, having a compelling online presence is paramount for businesses aiming to thrive in a competitive landscape. At the heart of this digital strategy lies an intricately woven tapestry of website design and digital marketing. It's not merely about having a website; it's about crafting an immersive digital experience that captivates audiences and drives business growth.
The Art of Business Website Design
Your website is...
|
by: tracyyun |
last post by:
Dear forum friends,
With the development of smart home technology, a variety of wireless communication protocols have appeared on the market, such as Zigbee, Z-Wave, Wi-Fi, Bluetooth, etc. Each protocol has its own unique characteristics and advantages, but as a user who is planning to build a smart home system, I am a bit confused by the choice of these technologies. I'm particularly interested in Zigbee because I've heard it does some...
|
by: agi2029 |
last post by:
Let's talk about the concept of autonomous AI software engineers and no-code agents. These AIs are designed to manage the entire lifecycle of a software development project—planning, coding, testing, and deployment—without human intervention. Imagine an AI that can take a project description, break it down, write the code, debug it, and then launch it, all on its own....
Now, this would greatly impact the work of software developers. The idea...
|
by: conductexam |
last post by:
I have .net C# application in which I am extracting data from word file and save it in database particularly. To store word all data as it is I am converting the whole word file firstly in HTML and then checking html paragraph one by one.
At the time of converting from word file to html my equations which are in the word document file was convert into image.
Globals.ThisAddIn.Application.ActiveDocument.Select();...
|
by: TSSRALBI |
last post by:
Hello
I'm a network technician in training and I need your help.
I am currently learning how to create and manage the different types of VPNs and I have a question about LAN-to-LAN VPNs.
The last exercise I practiced was to create a LAN-to-LAN VPN between two Pfsense firewalls, by using IPSEC protocols.
I succeeded, with both firewalls in the same network. But I'm wondering if it's possible to do the same thing, with 2 Pfsense firewalls...
|
by: adsilva |
last post by:
A Windows Forms form does not have the event Unload, like VB6. What one acts like?
| |
by: muto222 |
last post by:
How can i add a mobile payment intergratation into php mysql website.
| |