I can't find any code for doing this. The only places I can find it is in GIS APIs. Preferably in java, but I can port other languages too. I'd even settle for a overview of all the formulas required.
Use either:
The method Geometry.buffer(distance)
in Java Topology Suite (JTS) library http://www.vividsolutions.com/jts/JTSHome.htm
The GEOS
http://trac.osgeo.org/geos/
port of JTS library to C++.
I'm a little puzzled by your question, so this may not be the (type of) answer you are looking for.
Look for line buffering code in the source files of any of the open-source GIS out there. there are several.
As for algorithms, I Googled for gis buffering and got several useful hits on the first page.
Related
I'm looking for programmer's guide for PIC16F1947 micro but so far couldn't find such manual. Is it available online? If yes, where can I find it?
I've searched microchip.com and Google but didn't see such manual.
By programmer's guide I mean a manual for us, the programmers. The manual should contain how to write programs for PIC micros (e.g., how to write interrupts, what does __config do, which files to include etc).
Thanks.
EDIT
I'll use MPLAB IDE 8.46, ICD 3 and HI-TECH C Compiler 9.81.
This manual will probably work as a starting point. It talks about things like interrupts and generally how to perform various simple tasks: http://www.cs.ucr.edu/~eblock/db/downloads/PICmanual2.pdf
You will still need the datasheet and/or the programming guide to perform more complex tasks. Those documents will provide the necessary details to drive functionality on your specific chip. Here's a link to the programming guide: http://microchip.com/wwwproducts/Devices.aspx?dDocName=en538146
I found a data sheet for the PIC16F1947 catalogued here; not sure if it's the right one:
http://www.alldatasheet.com/view.jsp?Searchword=PIC16F1947
(Passing this site on, as even though it's not the manufacturer's site, it's a really good resource for finding data sheets; I'm not affiliated.)
ETA: Hmm, well, it used to be a good site, but it seems less so, now.. Leaving this here in case it is still useful.
I need to deliver a presentation on programming in MPI. I need to add a segment on how MPI works under the hood. For Example What happens when I call MPI_Init?
Do you know of any good source from where I can learn these details?
The MPI Spec contains the description of the knobs, sliders, and displays that are on the outside of the "black box" of each API.
The interior details of the black boxes will be implementation dependent...and will also depend on the interconnect (e.g. TCP, IBV, DAPL, etc), the OS (e.g. is the implementation using LSB, or native libraries, etc), and on many other factors to a lesser degree (e.g. message size thresholds will trigger different code paths, and so on). Using "strace" and "ltrace" on the a.out may provide some insight into the actual goings on inside the blackbox.
The best recommendation is to pick an open source implementation and examine the code to determine the internal details.
MPI is a specification, not a particular implementation. The observable behavior is given in the MPI spec. How it works under the hood depends on the particular implementation. If you'd like to take a look at an example implementation, you might be interested in looking at MPICH2 and browsing their source code.
Complement your study of the source code of an implementation of MPI with consideration of how you would implement MPI_Init on your platform of choice. MPI sits on top of already available O/S functionality. I don't mean to suggest that you can figure out how a particular version of MPI is implemented by this approach, but to suggest that you can learn better what is going on under the hood by tackling the problem from another angle.
MPI is only a spec. MPI spec is implemented by various groups and organizations. You will want to pick one implementation, say, MPICH, and you can find their design documentation. That will tell you how the MPI spec is implemented by that group.
If you just want to describe what happens when an application written in MPI is started, you can read about MPI and MPI programming. I highly recommend http://www.citutor.org
I'm new to this field - but I need to perform a WAV-to-MIDI conversion in java.
Is there a way to know what exactly are the steps involved in WAV-to-MIDI conversion?
I have a very rough idea as in you need to;
sample the wav file, filter it, use FFT for spectral analysis, feature extraction and then write the extracted features on to MIDI.
But I cannot find solid sources or papers as in how to do all that?
Can some one give me clues as in how and where to start?
Are there any Open Source APIs available for this WAV-to-MIDI conversion process?
Advance thanks
It's a more involved process than you might imagine.
This research problem is often referred to as music transcription: the act of converting a low-level representation of music (e.g., waveform) into a higher-level representation such as MIDI or even sheet music.
The sophistication of your solution will depend upon the complexity of your input data. Tons of research papers address music transcription only on monophonic piano or drums... because they are easy to transcribe. (Relatively.) Violin is harder. Voice is even harder. Violin plus voice plus piano is much harder. A symphony is nearly impossible. You get the picture.
The basic elements of music transcription involve any of the following overlapping areas:
(multi)pitch estimation
instrument recognition, timbral modeling
rhythm detection
note onset/offset detection
form/structure modeling
Search for papers on "music transcription" on Google Scholar or from the ISMIR proceedings: http://www.ismir.net. If you are more interested in one of the above subtopics, I can point you further. Good luck.
EDIT: That being said, there are existing solutions that we can all find on the web. Feel free to try them. But as you do, evaluate them with a critical eye and ear. What types of audio signals would cause transcription to fail?
EDIT 2: Ah, you are only doing this for piano. Okay, this is doable. Music transcription has advanced to the point where it can transcribe monophonic piano pretty well. A Rachmaninov concerto will still pose problems.
Our recommendations depend upon your end goal. You state "need to perform... in Java." So it sounds like you just want something to work regardless of how it gets you there. In that case, I agree 100% with others: use something that exists.
That's actually an interesting question; all of the MIR libraries I know are typically C/C++/Python/Matlab. But not Java. The EchoNest has a Java API, but I don't think it does note-level transcription. http://developer.echonest.com. (Edit: It does note-level transcription. The returned data includes pitch, timbre, beat, tatum, and more. But I find polyphony is still a problem.)
Oh, Marsyas is Java-based. Cool. I thought it was just C++. http://marsyas.info/ I recommend this. It's developed by George Tzanetakis, a professor in MIR. It does signal-level analysis and should be a good option.
Now, if this is for a fun learning experience, I think you can use the sound manipulation utilities in Java to experiment with the WAV signal and see what comes out.
EDIT: This page describes MIR software better than I can: The Tools We Use
For Matlab, you may be interested in the MIR Toolbox
Here is a nice page of common datasets: MIR Datasets
This is a very big undertaking for being new to the field, unless you mean you are familiar with signal analysis and feature detection in general and want to look more specifically into automatic transcription.
There is no API for WAV to MIDI conversion. Vamp is a framework for feature extraction plugins, but to do automatic transcription you would need to use all the functionality of the existing plugins, plus implement functionality that exists in none of them yet.
Browse through the descriptions of the plugins on the vamp download page, any descriptions you do not understand are topics you should start researching if you want to do this.
If you don't need to automate this task (ie, for a website where people can upload MP3's and get MIDI files back), then you should consider using a tool like Melodyne which is already quite good at going this. As Steve noted, this is a very difficult task to accomplish, and even the best algorithms and solutions present at the moment are not 100% reliable.
So if you are just doing studio work and need to do a few conversions, it will probably save you a bit of time (and lots of headache) to use a tool already designed for this task.
This is a field which is still highly under development, yet, there are some (experimental) algorithms available.
You can install sonic annotator and use a few vamp plugins.
For example:
./sonic-annotator file.wav -d vamp:qm-vamp-plugins:qm-transcription:transcription -w midi
./sonic-annotator file.wav -d vamp:silvet:silvet:notes -w midi
./sonic-annotator file.wav -d vamp:ua-vamp-plugins:mf0ua:mf0ua -w midi
Dolphin, sorry to be brusque, but you have completely underestimated the problem. What you want to achieve - a full piano sound transcription involving all parameters that were used while playing would need an enormous amount of research with people who have worked in the field for many years. Even a group of PhDs in signal processing would have to invest a lot of work to even come close to what you mean. Music transcription has needed decades of work to even work halfway reliable. I'd suggest you pick a different problem which you can manage better than this.
I have inherited a flex project which is sadly not documented. Im looking for a documentation generation tool / class diagram generater or something like that which works with actionscript. There are around a 1000 class files and I don't have the time to step through all the code in debug.
I have tried a few tools like Doxygen (set the language to java) and NaturalDocs but that didn't work out too well.
No idea for the document generation, BTW, would it really help with a huge bulk ASDoc ?
Regarding the diagram generation I posted an answer for the following question. Not sure the guy ever found out, I'm interested about the matter as well.
Static Actionscript code analysis?
Consider this just a pointer, but Enterprise Architect supports round-trip source code engineering for Actionscript (it's the only tool that can generate UML from AS source code, that I'm aware of).
I haven't used it much, just tried it some time ago, but perhaps it's worth a shot. I think it has a 30-day free trial.
If anybody else is looking for an answer, I would recommend using Crocus Modeller, UML modeling tool for AS3 & FLex with reverse engineering feature.
Are there any real world applications written in the Clean programming language? Either open source or proprietary.
This is not a direct answer, but when I checked last time (and I find the language very interesting) I didn't find anything ready for real-world.
The idealist in myself always wants to try out new languagages, very hot on my list (apart from the aforementioned very cool Clean Language) is currently (random order) IO, Fan and Scala...
But in the meantime I then get my pragmatism out and check the Tiobe Index. I know you can discuss it, but still: It tells me what I will be able to use in a year from now and what I possibly won't be able to use...
No pun intended!
I am using Clean together with the iTasks library to build websites quite easy around workflows.
But I guess another problem with Clean is the lack of documentation and examples: "the Clean book" is from quite a few years back, and a lot of new features don't get documented except for the papers they publish.
http://clean.cs.ru.nl/Projects page doesn't look promising :) It looks like just another research project with no real-world use to date.
As one of my professors at college has been involved in the creation of Clean, it was no shock he'd created a real world application. The rostering-program of our university was created entirely in Clean.
The Clean IDE and the Clean compiler are written in Clean. (http://wiki.clean.cs.ru.nl/Download_Clean)
Cloogle, a search engine for Clean libraries, syntax, etc. (like Hoogle for Haskell) is written in Clean. Its source is on Radboud University's GitLab instance (web frontend; engine).