paul.luminos.nl

This article scored me a grade of 9 out of 10.

If you are interested in this topic, I urge you to work your way through it. Personally, I enjoyed researching GNSS very much.

It was brought to my attention that the file was corrupt. This must have happened while moving the site a few months back, but I never noticed.

The problem has been fixed and the file can now be downloaded again.

Dear Paul,

Hello from a student in The TEchnical University of Sofia, Bulgaria.

I study last year " Aeronautical Engineering and Technologies" + Avionics.

My prof. of "Navigation" asked me and another student , together with me, to make a report on GPS, or comparison of GPS and Galileo....something like co-project, as I should speak for GPS in more details. After searching the internet, I found your site...and I like it very much - especially http://paul.luminos.nl/document/6, which is very much close to my theme. I want to thank you about this great work, and would be happy if you have additional materials and documents - presentations...etc... and if it is not bothering you - to send me these to: bojkins@abv.bg

Again, thank you, and I will look forward to your reply!

Have a nice day!

Regards,

Bozhidara

Thank you for the kind words!

I only have three documents on the topic:

• A technical article about the workings of GNSS
• The matching 30-minute presentation
• A brief newspaper article celebrating 45 years of GNSS

If you want to read more, I urge you to follow the references in the first article. Several of them point to quite informative websites that have much more in-depth information.

Other than that, I'm afraid I can't be of much help. Although I find Aeronautics very interesting, I myself am a computer sciences student that has no background into GNSS except this single research topic.

I wish you the best of luck, and am glad I could help!

I'm very interested in going through the 30 minutes presentation, but unfortunately it seems to be corrupted? (I'm running MAC Office 2008). In couple of your early posts you had mentioned the file might be corrupted. Do you know if this is still the problem? I will attempt to run the ppt when I get a hold of a PC. Thanks for the help.

The download works just fine. I haven't tried it on Office for Mac; perhaps that's the problem. If you would rather have it in PDF format, let me know and I'll upload it.

Just like the article, I scored a 9 out of 10 with this presentation.

Paul:

The file satellite_navigation.ppt seems to be corrupted... I can't open it with PowerPoint 2003.

Regards

Antonio

The problem was an apparent memory problem on the server's side. It's been fixed.

Your presentation is great.I am animated. Thank you!

Some server problems from a while back were causing the download to cut off at 2 MB, corrupting the file. I've fixed the problem, the download should work fine now.

This is an older version.

I revised the algorithm this year, and it works much better. This will go online soon.

Thank you

Dear Paul,

Thank you very much.

May I get knn code in JAVA?

May email address: [removed]

Thanks & regards,

Rita

Thank you for your feedback, Rita. I've sent you an e-mail with more information.

Also, I removed your e-mail address above to prevent any abuse (spam or otherwise).

Paul - thank you very much for providing this example - it was very well done and informative.

Hi Paul,

I was wondering if the KNN code you have, could it work for images. I need KNN for image processing. Also, if i can get the code in C/C++, that'd be great.

Regards,

Ali.

Boy, if it'd work with images! No, I'm afraid it can't do that.

If you could manage to find an effective way of determining a qualifying factor for a target image, say x factors, you could run the algorithm on a test set and evaluate the quality of each factor using cross-validation (for example the relatively simple leave-one-out-cross-validation).

Better yet would be if you could write an algorithm that randomly enumerates an x number of factors and decides on its own which ones give the best results.

Some rules that come to mind would be measuring the color/luminance of a pixel (or set of n×n pixels), the distribution over a row or column, overall hue, etc. etc.

I'm afraid I don't have a C/C++ version of this code. Visual Basic is an extremely accessible programming language, it should be relatively easy for a C-programmer to understand. I thought I had a Java version somewhere, but I can't find it at the moment.

hai paul,

Do you have the code in C if you have can you please send me.

looking for reply eagerly.

With regards,

Bawya.S

No, I'm afraid I don't have a version with C code. Like I said before, Visual Basic is rather easy to understand and you might want to try translating it to C yourself.

Also, it was brought to my attention that the download files were broken; this has been fixed and improved.

hi paul,

may I get knn code in java?

my email address: jasmine [underscore] siy [at] yahoo [dot] com

thans a lot

God bless

jas

Hi Paul,

Can I get a linux version of the code.

I'm afraid not. Visual Basic is only for Windows, and presently I don't have a Java (or C++) version. I've gotten so many requests over the years that I'll consider writing one, but no guarantees.

There has been a lot of interest in a Java version of this code. I am pleased to announce that I have released such a version, which is now available for download from this page. Feedback is, as always, welcome!

Hi Paul

I'm interested in your implementation. Do you have a English version of a document?

Thank you

Andrea from Brazil

You're in luck, Andrea! Typically I'm too busy to do that kind of thing, but I had been wanting to get around to that, so I updated both the application and the summary report.

The report is now in English and has been substantially expanded and clarified. I hope this helps you.

Hi Paul,

is your implementation of KNN capable of performaing spatial searches? I have a large list of points (250,000) in lattitude/longitude and for a given point I need to find 1-5 nearest points. The given point will not be in the list.

Is this possible with your KNN?

Thanks,

Igor

No, this implementation is not suited your proposed problem.

With some code modifications you might be able to fix it up to do that, but I wouldn't recommend this particular application as it only supports a small dataset and only understands classes with non-scalars.

Instead, you might find it worthwhile to look at my Java implementation, jKNN, which is less strict. Also, the code is more understandable and easier to adapt.

Either way, a lot of tampering with the code will be required in order to get it to do what you want.

Good luck!

Dear Paul,

Thank you very much.

May I get knn code in JAVA?

May email address: [yihanzd@163.com]

Thanks & regards,

Jack

In both the original post and in my previous comment I've placed a link to the Java version.

Hi Paul,

Sorry if you got this twice but I really need your help. Thank you for providing the application and summary report. It was very well done. But I have a problem, how can I load the dataSetSituations from a string array for example. I tried but i got error "cannot convert from String to KnnValue" and "cannot cast from a String to KnnValue". Can you give some advise please.

Best regards,

Myriam

Hi

Myself Rohit Kumar Singhal

I want Knn implementation for Mobile Customer Relationship Database

Please Help Me

Bye

hi,

Just curious if I can use the same method to find where along a given set (a super set) of (X1,Y1....Xn,Yn) Coordinates does another set (Sub Set) of Points (A1,B1...Am,Bm) align? Or are at the closest.

Thanks a lot & Regards,

Harish

It would seem to me (if I understand your question correctly) that you are simply looking for a sorting algorithm, Harish. If you want to determine which points are nearest to each other, simply compute the Euclidean distance from each point from the first set to each point in the second set.

I would suggest you look in to the Hausdorff distance or the Mahalanobis distance, depending on whether one of the sample sets is unknown or not (i.e. taking probabilities into account or not).

An alert commenter notified me of a minor bug in the Visual Basic version of the code, that caused training set examples with distances of precisely 0 not to be registerd as a nearest neighbor. I've fixed the problem and updated the code provided via the link above.

I've made some additional modifications to the application, including improved support for Vista. The foremost change in functionality is that in scaling mode, the test scenario is now scaled as well, opposed to only scaling the situations training set.

The new version, 1.2, is now online and available for download via the above link.

Hello! thanks for information about this subject and article..

But i have a problem that your winrar archive for KNN algortihm in VB or JAVA gives errors when extracting, please help me to see your full codes may you please send me knn codes in java and vb?

thanks a lot.

A bug in Internet Explorer was causing the downloaded files to corrupt; any other browser would have worked. I patched it up for IE, though; the download should be working fine again.

Thank you so much, i have downloaded the rar files now without any problem. Thanks for your attention..

Hi, I think that you've made mistake writing formula for euclidean distance number 2.

http://en.wikipedia.org/wiki/Distance

Yes, you're right: it presently states Euclidean distance as:

∑ ( √ ( x² - y² ) )

This should be:

√ ( ∑ |x - y|² )

I revised the Naive Bayes demo application (v1.1) to make it more understandable. The program demonstrates how certain parameters determine the classification in one of two datasets. It returns a numeric value indicating it's certainty and features two forms of feature analysis:

1. Leave-one-out-cross-validation: remove any number of features by cross-validating.
2. Feature Selection: select the best of feature(s) based on the deviation(s).

The explanation during each process has been improved. Any feedback is welcome!

first thabnk for efforts

with the concern of programe it good, but if i want to apply it to the case the number of date more than 14 as in your example

i suugest in order the programe to be more efficiency to make database insert in it all case rgardless the number of date

wonderful

Paul,

Thanks this is very helpful to me. I am adding Niave Bayes to at ML project http://h202276.dreamsparkhosting.com/

Brian Keltch

Great to hear it! Coincidentally, my brother did genetic footprinting of the Hepatitis C virus as a graduate student at Yale in 2007.

We've combined our fields of expertise to create better software for molecular biologists. We started a bioinformatics company, CrimsonBase.

I haven't been able to find the application and source code that are discussed in the article so far. If I ever run into it, I'll be sure to update the post.