[Biococoa-dev] BCSequence class cluster? [Was Re: Introducing myself]
craig at batemanspace.com
Fri Feb 27 15:39:10 EST 2009
After looking at this for a while, I agree that a protocol would do it, and
would be consistent with using an Interface in many other languages, but a
BCSequence class cluster (and probably a BCSequenceArray cluster that
included a sequenceWithId: method since many file formats support multiple
sequences) might be a bit more elegant. Especially if we're serious about
wanting a BCMutableSequence.
This pattern is common in objective-c when you have multiple classes that
all implement the same interface and the actual class to use
is discernible at the time of construction. It's a little harder to
implement, but then consumers of the library don't need to worry about which
class(es) they need for a given purpose.
The pseudo-code to use them would then be something like: (Sorry about the
naming here, I don't have the source in front of me as I write this)
BCSequenceFile *myFile = [BCCachedSequenceFile fileWithContentsofFile:@
BCSequenceArray *myArray = [BCSequenceArray arrayWithSequenceFile:myFile];
BCSequence *first = [myArray sequenceAtIndex:0];
BCSequence *mySeq = [myArray sequenceWithId:@"GYS2"]
The end user would be given an instance of BCCachedFastaFile in myFile,
BCCachedSequenceArray in myArray and BCCachedSequence for the two sequence
calls. This would all happen transparently behind the scenes and they
wouldn't necessarily need to know what class they were using. Externally
the memory vs file sequences look the same. Internally the memory
BCSequence utilizes an NSData while the file-based one utilizes an
NSFileHandle with an NSRange over the sequence (at lesat that's how FASTA
would work, other format implementations would vary significantly).
I'm pretty sure this can be done without introducing any breaking changes.
Does anyone object to me attempting to implement these this way?
On Wed, Feb 25, 2009 at 4:01 PM, Scott Christley <schristley at mac.com> wrote:
> Hey Craig,
> Well that is great, really. Sounds similar to my experience, I entered my
> PhD to do core computer science, software engineering, then got involved
> with a biology project, was hooked and been following every since.
> One thing you might want to look at are the two main genome browsers that
> exist today, one by UC Santa Cruz and the other by Ensembl.
> There is also a project that I'm involved with, VectorBase, which also uses
> the Ensembl browser.
> The reason I point these out is because all of them are web-based, which is
> great, but a potential killer app "might be" to have a local application
> which would allow researchers to analyze their local data. Reproducing the
> functionality of these genome browsers isn't the way to go, but there are
> many potential niches to be filled.
> Yes, shotgun sequencing is exactly what it is called. Humorous name for
> sure, but you are exactly right, the "shotgun" blasts the genome into many
> smaller bits, which are then assembled together afterward. It was quite
> controversial when Venter's company took the approach for the human genome
> project, in defiance of the public consortium which was doing it the
> expensive, slow, but more accurate way. But now it is the standard way,
> though its not perfect, and assembly in general is a difficult problem.
> So for the BC*Sequence classes, if you look in the BCSequenceIO group then
> you will find a BCCachedSequenceFile and BCCachedFastaFile classes, which
> handle the file I/O. What is missing is a BCCachedSequence class, to
> correspond to BCSequence. From a design perspective, the two classes should
> stay separate (memory-based versus file-based) but I think a protocol which
> defines a common interface is what is needed.
> On Feb 24, 2009, at 2:31 PM, Craig Bateman wrote:
> I accidently dropped the list in my reply, so Scott was the only one that
> got it.
> ---------- Forwarded message ----------
> From: Craig Bateman <craig at batemanspace.com>
> Date: Mon, Feb 23, 2009 at 2:01 AM
> Subject: Re: [Biococoa-dev] Introducing myself
> To: Scott Christley <schristley at mac.com>
> Well, unfortunately I can't state what, in particular interests me about
> genetics, mostly because I know so little. I read the blind watchmaker and
> was intrigued by the author's explanation of how genes work, and since then
> have read other books about the human genome and the effects of certain
> genes on human development, etc. I guess I'm just vaguely interested in
> genetics research because I want to know. I certainly can't state that I'm
> interested in any one sub-topic over any other. In short, I've barely
> scratched the surface, and want to learn so much more...
> I am, however, an avid programmer, and was hoping that my vague interest in
> the domain of genetics coupled with my years of writing software (banking
> analysis software, but software all the same) would combine to provide a
> great developer resource for the project.
> As far as a "killer app" goes, I couldn't even guess what something like
> that would look like for BioCocoa... If you have some ideas I can certainly
> bring something to light, but honestly I haven't a clue about how any of
> this sequence information is actually used and/or what features in such an
> app would be useful.
> Unifying the BC*Sequence classes is a good idea, maybe I'll look at that
> first as a tooth-cutting exercise. Aside from that, I read a bit about
> "shotgun" sequencing, which may not be what it's actually called, but where
> overlapping bits of a sequence are used to assemble an entire sequence.
> So I've got a lot to learn, but anything I can contribute to this project
> or genetics/proteins/cancer/whatever research in general is a win in my
> On Feb 22, 2009, at 11:16 PM, Scott Christley wrote:
> Hello Craig,
>> The coding I've been doing lately is primarily related to the research I'm
>> doing, so from this sense it doesn't necessarily go fast. My long-term goal
>> is to add some advanced analysis techniques into BioCocoa.
>> One of the key things I would like to do is make the sequence and cached
>> sequence class correspond in their interface. The cached sequence class is
>> important to do large scale analysis on large genomes, because they are too
>> big to load completely into memory. This is something that BioCocoa can
>> offer above other toolkits like BioPerl and BioPython, high performance and
>> large scale analysis.
>> What interests you about genetics? Much of the algorithms in genetics,
>> bioinformatics and so on are still being developed, even things like
>> assembly of genomes is not a "done" technology. If you have a specific
>> interest area, then I can help lay out a series of tasks that would be both
>> highly useful and be interesting algorithmic work.
>> Koen is right, the todo list is still accurate, and those are certainly
>> useful enhancements to make. And the creation of a "killer app" is
>> definitely desired, especially to bring these advanced analysis techniques
>> together into an easy-to-use GUI and/or command line applications that
>> biologists can use.
>> On Feb 21, 2009, at 12:43 PM, Craig Bateman wrote:
>> I'm an experienced software engineer looking for an open source mac
>>> project to contribute to, and I'm recently very interested in genetics. So
>>> BioCocoa seemed an obvious choice.
>>> I looked at the To Do list, and fear that 2+ years later it must be out
>>> of date unless there's just nobody left working on this project. Is it
>>> officially dead? There hasn't been a lot of movement on this list in the
>>> past few months since the 2.1.0 "non"-release. I've checked out the source
>>> and will start digging now to get a feel for what's here and how it works.
>>> What/where are the primary missing pieces? Has all the 1.x functionality
>>> been incorporated to 2.1? Is anything on the todo list still up for doing?
>>> Should I be looking at the framework itself or the applications?
>>> Anyway, to whoever is still alive on this project, let me know how and
>>> where I can help and I'll be glad to.
>>> Craig Bateman
>>> Biococoa-dev mailing list
>>> Biococoa-dev at bioinformatics.org
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