Fours and Fives

Playing with Twine

2009-04-06T11:45:00.000-07:00

I've been playing with Twine a bit lately, and I have to say I don't yet get the point... I don't yet see what value ontology adds to the type of service being provided, other than slowing down whatever it is the site's doing. Naturally it makes no sense for them to tell you what the underlying ontology is doing for you. The ultimate value is the utility the site provides after all, and not the specific underlying technology. Next I'll try creating and adding to a twine, let's see if that gives me more of an insight.

Sesame+OWLIM+Tomcat

2009-03-24T07:05:00.000-07:00

Yesterday I think I managed to set up Sesame 2.2.4 with OWLIM 3.0 Beta running on Tomcat 6.0.18. The process is not documented anywhere very well. I found the solution on a mailing list, in messages posted last year, which wasn't archived where I would have expected. Frustrating. I hope this blog posting is a little easier to find and follow.

So, here's what you do... There are two broad steps, which are very similar to one another: set up the sesame console, and set up the sesame+tomcat server.

First sesame+tomcat.

Unpack openrdf-sesame.war in tomcat webapps.
In the WEB-INF folder, put the two jar files from OWLIM.
Find your sesame preferences folder. For the mac that would be ~/Library/Application Support/Aduna/OpenRDF Sesame/. Create a folder templates, and put the content below into owlim.ttl.
Start tomcat.

#
# Sesame configuration template for a owlim repository
#
@prefix rdfs: .
@prefix rep: .
@prefix sr: .
@prefix sail: .
@prefix owlim: .

[] a rep:Repository ;
rep:repositoryID "{%Repository ID|owlimTest%}" ;
rdfs:label "{%Repository title|OWLIM Test store%}" ;
rep:repositoryImpl [
  rep:repositoryType "openrdf:SailRepository" ;
  sr:sailImpl [
     sail:sailType "swiftowlim:Sail" ;
     owlim:ruleset "{%Set of rules|owl-max%}" ;
  owlim:partialRDFS  "{%Partial RDFS|true|false%}" ;
     owlim:noPersist "{%No Persistence|true|false%}" ;
     owlim:storage-folder "{%Storage folder|owlimTest-storage%}" ;
   owlim:base-URL "http://example.org/owlim#" ;
     owlim:new-triples-file "new-triples-file.nt" ;
     owlim:entity-index-size "200000" ;
     owlim:jobsize "200" ;
   owlim:repository-type "in-memory-repository" ;
   owlim:imports "{%imports(';' delimited)|./ontology/owl.rdfs%}" ;
   owlim:defaultNS "{%defaultNS(';' delimited)| http://www.w3.org/2002/07/owl#%}"
 
  ]
].

Next, set up the sesame console. If you don't plan on using owlim without tomcat, I don't think the following steps are necessary

In the sesame folder's lib directory, add the owlim jar files.
In ~/Library/Application Support/Aduna/OpenRDF Sesame console/templates put owlim.ttl.

Now we go on to creating an owlim repository. While I've gone through this procedure myself, I haven't yet tested if the repository is behaving like an OWL triple store. You have been warned.

Start the console.
Assuming default parameters with tomcat running on localhost, connect http://localhost:8080/openrdf-sesame.
create owlim.
Provide appropriate parameter values, and you're all set.

You should now have an owlim repository.

Bibble 5

2009-03-06T10:14:00.000-08:00

BibbleLabs has put out a preview of Bibble 5. Old news for many, I realize... This happened over a month ago. But I've been waiting for this. Adobe Lightroom is a good piece of software and a significant step up from my experience with Bibble 4. But it's s-l-o-w. I realize my PC is a bit old, even so redrawing the interface should not take tens of seconds. I haven't even fired up Bibble 5, so no first impressions to report yet.

Semantic wiki progress

2009-03-04T10:09:00.000-08:00

So I now have some code that can execute some simple operations on the Sesame REST API... The next step wasn't entirely clear, at this point I've settled on authoring a simple ontology viewer that builds on top of this API. For now I'm calling it CLOVER. Eventually I'll put XL-Wiki and CLOVER into a single piece of software. That software is currently called CL-Wise, which will need radical restructuring (in what little has been implemented) to accommodate a component based structure. Components because an ontology viewer does not exactly fit into a wiki structure, though the two are easily combinable into a coherent whole.

I've been out of touch with developments in the Common Lisp world other than blogs (IRC and comp.lang.lisp are too chaotic for my liking), and haven't seen any discussion of component based architectures. I hope this doesn't turn out to be too complex.

SCOLI unleashed

2009-02-27T09:37:00.000-08:00

I have finished up enough work on my Sesame API, SCOLI, to advertise it as a real project. The API is based on Sesame 2.x's REST API. Right now it is still in fairly primitive state, capable of doing simple retrievals but not much else. As soon as I have simple assertions worked out, I will be hooking it up to CL-Wise, my semantic wiki project, and start making progress on that again. SCOLI will be developed on an as-needed (or perhaps as-requested) basis.

CL-Wiki reborn

2008-12-16T17:08:00.000-08:00

I have renamed my fork of CL-Wiki as XL-Wiki. Still need to make a few changes to wrap up the renaming.

Now with project pages!

2008-12-14T16:01:00.001-08:00

I've finally gotten around to creating project pages for CL-Wiki (my fork) and CL-Wise, my experiment with semantic wikis. I've also added a little test suite based on FReT. The first time I'm actually using FReT for anything useful since I'd written it.

Photography updates

2008-11-29T12:13:00.000-08:00

My nature photography class is coming to an end. So I thought I'd do a little wrapup in everything I've attempted through the course of the class. Other than the field trips, we had a trip up to Mendocino, and from there up to the Redwood National Park.

Here are the links to the relevant flickr sets, picking out individual photographs is far more work:

Point Lobos State Reserve
California North Coast
Mendocino
Moss Landing
Mountain View Shoreline

(Not yet) A semantic wiki for common lisp

2008-11-07T17:08:00.000-08:00

I have put in a stub of a semantic wiki for common lisp, in an svn repository, here. It requires my fork of cl-wiki, also in svn, here. I have to have a better name for my fork of cl-wiki than "my fork of cl-wiki". Definitely uncool.

Also have to throw together some web pages for these projects.

Perspective on the financial crisis

2008-10-27T22:52:00.000-07:00

So, there's at least one person out there who seems to share my opinion on the nature of the financial crisis... This was in Business Week. I hope the link lasts, I didn't see any indication that it would expire but the URL itself doesn't give me confidence.

Photographing birds

2008-10-22T13:37:00.000-07:00

Last weekend I went out to photograph birds. It was a field trip organized through the class I'm taking. For the trip I rented myself a 300mm f4 and a 1.4 extender.

First the sites. We visited two spots: the Mountain View shoreline, and Moss Landing. We got to the Mountain View shoreline about 8am. I was there over two hours. The morning was very foggy, but windless. Not the worst conditions, but certainly not the best. I couldn't crank up the shutter speed without compromising on the ISO, and was shooting at f4 most of the time. There were an immense number of birds at this site. Really fantastic. Shorebirds, water fowl, sparrows... Even spotted a pheasant.

Moss Landing was a bit of a mess. It isn't the most pleasant site, and the person that had arranged the location wasn't able to make it there himself. There were lots of sea lions and a few otters. Lots of birds, slightly different from the ones at Mountain View. I was trying to photograph cormorants flying just above the water. These are hard birds to track! Though I think I got a few reasonable shots. Once again, light was a problem. Very foggy. But there was a little break on the horizon that let through a nice sunset.

I'm still working through the photos. I had several hundred by the end of the day. Working with a 300mm lens was immensely challenging. It's a wonderful piece of equipment. I'm leaning towards skipping the 70-200mm and moving straight up to the 300mm. If I need reach, I should get a lens with some real reach. At least that's my reasoning.

On the other hand, the 70-200mm will give me a good focal length for doing portraits. And is likely much more portable. The 300mm f4 is a heavy beast.

I don't think I'll be making a decision this year though. Budget constraints and all that.

OWL in Lisp!!

2008-10-10T09:20:00.000-07:00

I got a lead yesterday on some OWL parsing and generation tools implemented in Lisp. Apparently in the process of being open sourced. The back-end store on their project is Sesame. I don't know if they will be releasing their triple store bridge along with the rest of the tools.

Needless to say, this is seriously exciting to me! I will switch from working on my triple store API to CL-Wiki for now. I need to write up a design document as a first step.

Wilbur-rdf is not usable

2008-10-07T22:50:00.000-07:00

I've just spent a bunch of time on wilbur-rdf that I could have used for doing something more useful, and have nothing to show for it.

The key problem is NOKOS, or the Nokia Open Source License. This license is based on the Mozilla 1.1 license. A full reading of the license shows that if the software is covered by a patent, and the software is modified, then the patent must be re-licensed. (See here for the discussion on Debian Legal mailing list.) Unfortunately there is a patent covering wilbur-rdf. So this software is unusable in the manner I was hoping: componentize it, and apply it towards building a semantic wiki.

I'll have to start over from scratch: put together a triple store API, then build a triple store capable of dealing with OWL. Parsing OWL, RDF etc. will have to take a back seat for now.

Hacking Wilbur

2008-10-07T10:26:00.001-07:00

I've now got wibur in my svn repository, and have been fixing it. Currently the software isn't functional.

The tendency to not reuse is evident in force in wilbur. It has its own XML parser and HTTP client. Granted, these didn't exist as components in the lisp world when the project started, but that's hardly the case now.

My first task is still to pull out a triple store and the triple store API from wilbur. I really need to have them be independent components before I can turn cl-wiki into a semantic wiki. I'll get to the rdf parser in time, when it comes to importing ontologies into the semantic wiki.

(Or should importing existing ontologies be the first step? Hmmm....)

cl-wiki, wilbur now in my svn repository

2008-10-06T11:33:00.000-07:00

I have been reorganizing my svn repository. All the public projects have been moved to http://svn.sfmishras.com/public/. This includes cl-wiki and wilbur. I'm forking cl-wiki, as the current maintainer isn't interested in further developing the project. And wilbur as it exists on sourceforge is dead. In emails exchanged with Ora Lassila, I found out they are putting out a successor project named piglet based on Python and C++. I'm not likely to be interested in that.

The key reason behind these steps is that I wish to develop a semantic wiki in Common Lisp. There are many pieces I see in this effort. The following are just the starting point:

A wiki. Therefore cl-wiki.
The ability to import and export OWL. Therefore wilbur.
A triple store API. To be factored out of wilbur.
A triple store. Again, to be factored out of wilbur.

I don't know how to put together a triple store, or how to organize the triple store persistence. So this is going to be quite a learning experience. The reason for refactoring wilbur is twofold:

Multiple software components will access the triple store. Just in the list above we have two: the import/export component and the wiki.
Having a standard triple store API will help interoperability as new CL components are (might be? could be? am I just dreaming?) developed.

Given the key role of the triple store API, refactoring wilbur will be the next step.

The Financial Crisis Isn't Going Away

2008-10-06T11:32:00.000-07:00

I'm obviously no expert in finance. I'm just an observer. But I strongly believe that being on the outside is necessary to spot when things are going wrong. Those on the inside get a view of the situation with too many details and possibilities, enough so that they aren't able to see the forest for the trees. This I think is what happened during the tech bubble. And I see it happening again.

I believe this financial crisis is multiple decades in the making, and will take a decade to sort itself out. I don't see anyone talking about what I believe is the key problem in the system: the wage stagnation of the vast majority of Americans. There's been quite a bit made of the growing income gap between the top 1% of Americans, and the remaining 99%, over the previous decade. This is, I believe, extremely unhealthy. I don't know what the situation was before then. My bet would be that the years preceding the actual increase of the income gap would have gone into prep work. In other words, the groundwork for the acceleratng income gap would have been laid down. The problem has in other words been created by both Democrats and Republicans.

Would the consumer be at fault? I think the consumer acted as would be sensible given the circumstances. Cost reduction and easy credit had made up for the loss of income for the vast majority of Americans. Moving jobs and factories overseas made it easier to keep a healthy supply of cheap goods coming in. So it was possible to squeeze through on falling wages. At the same time in the name of making housing more accessible to home buyers, easy financing was created. After all, in the absence of growing wages, it would be impossible for businesses to make money off consumers. I believe this would have been especially true of the mortgage industry. Easy credit was an incentive to make bad investment decisions, which everyone did. These investments led to asset inflation. Which led to further credit. And at some point the cycle had to break.

So, what's in store for us? Nothing good, I fear. Basically, housing costs have far outstripped income for many. The only real fix for this problem is to bring housing costs back in line with income. There are two ways this could happen, and both are going to be incredibly painful. You can either let house values drop. Or you can let incomes catch up. The result of dropping housing prices is already evident. And this doesn't seem to be working at all. Bringing up consumer incomes is also a long term solution. What, after all, are you going to do to bring up their income? Increasing income in this manner is going to lead to increasing inflation. So, everything will become more expensive to match the prices of homes. Not a pretty scenario.

What of the bailout plan that's been proposed? Say the government buys $700 billion of bad debt. What we're doing basically is setting up an entity to absorb losses in the housing market, an entity for which taxpayers are taking responsibility. So we're insuring ourselves. But how is that debt going to be repaid? Consumers don't have the income to support the houses they're in. There's nothing here that tells me how we're going to fix the housing situation. Say a house forecloses. We take a loss on the $700B. That foreclosure affects the values of other surrounding houses. And we have affected debt that formerly wasn't bad, debt that's presumably still in the hands of financial companies. Have we solved anything if this scenario, which I think is quite likely, comes to pass?

Updating my web site

2008-10-03T22:38:00.001-07:00

Modest improvements to my web site at http://www.sfmishras.com/. Most importantly, I have killed the silly animated front page and put in a link to some real content. Not that the content is currently all that interesting...

My next step is to update my svn repository with various projects that I'm planning on hacking. Starting with wilbur-rdf.

Expressiveness of Semantic MediaWiki

2008-09-30T22:34:00.000-07:00

Semantic MediaWiki (SMW) represents a concept as a page. Each page is exactly one concept. Each link to another page is potentially a triple, with an annotation on the link identifying the relation. This in a nutshell is the syntactic representation of triples in SMW. Categories potentially reflect classes, while normal pages reflect individuals. This gives a class-instance distinction.

This simple approach allows us to represent a variety of knowledge. But there are many other key constructs required for authoring a full ontology. I'll just give one example here: template vs own slots. These terms require some explanation. Template slots are defined on classes. Suppose (C1 r V2) is a triple representing a specification of a template slot. C1 is a class, and V2 is some valid value for r. By stating this triple, we're asserting that the filler of r in an instance of C1 must be V2. If r were an own slot, by contrast, C1 itself would have a value V2 in the filler of r. The instances of C1 would not be directly aware of this triple.

Further, the assumption that a single page describes only one concept is not tenable in any realistic situation. All but the simplest articles deal with multiple concepts. Splitting an article into components is often not feasible, as the content becomes too scattered for easy human consumption. I deal with both issues in the remainder of this post.

Given that we want to represent knowledge as succinctly as possible within the general wiki syntax, creating every semantic distinction within the wiki is a significant challenge. The SMW syntax is very simple, but the knowledge one can describe through it is too simplistic. A few straightforward changes can make SMW much more expressive.

Let's start with classes and instances. I don't think it is a good idea to conflate a class with a category, and an instance with an article. Each of these objects have distinct roles that are then lost. For example, each article is an instance of a class Document. The article discusses subjects that can be mapped to concepts. But the article is not itself a concept.

Here's a simple mechanism for producing such mappings. Each time an article discusses something that can be related to a concept, declare a start tag. At the end of the discussion, close with a end tag.

But, if an article no longer represents something in the KB, we can no longer rely on links to describe triples. This is easily addressed. Insofar as an article talks about anything, it is generally possible to define a primary topic for the article. Then a link is substituted with that primary topic when we're defining triples.

The nesting of topics also represents a relationship between those topics. This is similar to annotated links describing relations between concepts in the KB.

Allow a document to represent a class, an individual, or neither. This can be easily declared, just as categories are declared. This will enable documents to describe either classes or instances, or a combination of the two. The current SMW implementation supports linking categories to anything one wishes. However, categories do not show factboxes, except in previews. Asking for the OWL export of a category does not include the properties that had been included there. These may just be bugs, but as far as I know there exists no specification of the meaning of linking a category to another via a relation. One needs to be able to say whether a property linking two classes is intended as an own slot, a template slot, or a restriction on the slot filler of the source class. I would contend that in most cases one can deduce the intended meaning by considering the domain and range restrictions for a slot.

Effectively, my experience is that SMW can't describe anything but the most rudimentary content about classes. One cannot really develop an ontology in SMW as it exists today. At best one can describe basic taxonomy.

Photography class

2008-09-25T13:40:00.000-07:00

I have registered for a photography class. Digital nature photography, offered through the Palo Alto Camera Club. First time I'm taking a photography class, rather excited! I've learned a bit on my own so far about photography, but I really feel like I'm missing something... That I won't really get any better just working at it on my own.

Long overdue update

2008-09-25T10:04:00.000-07:00

I have been meaning to put together a blog entry for a long time, but finding time has been difficult. We went to the Eastern Sierras, where I was chased (briefly) by a bear. Lehman has tanked, and AIG has been on the brink. Freddie and Fannie are gone. Our house still needs work. I finally got my green card, right in time to see the economy go south. Lightroom 2 came out. And there were more events besides that I would rather not mention here. Where do I begin?

About the only big thing that I haven't covered here is programming and work. So I'll focus on that. My lisp hacking of late has been pretty routine. In fact, all my hacking has been pretty routine. I've been developing the server portion of our software, and it has been going as well as can be expected. Try as I might, I can't think of anything truly interesting I've done over the past few weeks. Time has been spent on bug fixing and other such tasks. Instead, I'll turn to one of the key aspects of our software: the manipulation of knowledge as a graph. This also ties in with one of my previous posts on hypergraphs.

We have viewed graphs as labeled edges connecting nodes. This has the obvious deficiency that this type of data structure falls outside the scope of many standard graph algorithms. My initial approach to addressing this problem was to construct different types of graphs to tackle the various algorithmic problems we faced.

One of the graph types was an edge graph. This graph has two types of nodes: one representing nodes, and the other representing edges. Suppose we have a triple (n1 s n2) in our KB. This translates to a graph with three nodes: n1, n1sn2, and n2. The edges in this graph are n1->n1sn2, n1sn2->n2. Slots don't have an explicit representation in this scheme. They are instead replaced with a representation of the complete edge.

Another type of graph is the node graph. Given a triple (n1 s n2) in our KB, we reduce it to an edge n1->n2 in our graph. Similarly, we can also define an "edge graph". Suppose we have two triples (n1 s1 n2) and (n2 s2 n3) in our KB. We can define an edge in our graph n1s1n2->n2s2n3 in our graph.

It is critical that these are not general purpose KB representation schemes. These are merely mechanisms for reducing the KB to a representation useful for solving certain problems. Hypergraphs by contrast provide a faithful representation of the triples in a knowledge base. A hypergraph could thus serve both purposes: represent the KB and provide a basis for implementing various knowledge manipulation algorithms.

So, how would DFS look in a hypergraph? I've picked on DFS as it is a key algorithm for finding certain structures in our KB. The answer is heavily dependent on the graph representation we choose. Suppose we choose to represent edges as a directed hypergraph. This can be done in one of two ways for a triple (n1 s n2): n1->{s,n2}, and . The former differentiates between the subject, predicate and object by assuming that the predicate is always clearly distinguishable from the object. This assumption is probably not going to hold for arbitrary KBs, so we must abandon this representation. The alternative has us store each hyperedge as an ordered tuple, which tends to go against standard hypergraph formalisms. However, it can reliably represent arbitrary triples correctly.

I must end this blog entry here, as I don't have a formal representation of the hypergraph. Implementing DFS over a representation is straightforward. The basic principle for DFS still applies: start with a root. Mark the current object as visited, then visit the next object. Don't visit any object multiple times. As such, DFS and BFS are straightforward general purpose graph algorithms. So most of the algorithms that build upon these can be straightforwardly translated to hypergraphs. But! It isn't the case that the results of the algorithms would be interpreted the same way as in ordinary graphs.

Discovering RESTful APIs

2008-08-10T09:17:00.000-07:00

Read up today on REST APIs. See this introduction for specific details. Here I'm just going to give my opinion.

The idea behind the REST style is appealing in its simplicitly. I can see Many ways in which rigorously following the style would produce an easy to understand API, provided the user (client) is also familiar with the style. We've all become so used to treating GET and POST in HTTP as equivalents that we don't even think about how we might be abusing the intent. I never did understand the intent behind the separation of GET, POST, PUT and DELETE until now, and even now that understanding is arguably superficial.

REST provides a set of constraints over an API. Does it make sense to have a framework for supporting REST style APIs? Would the framework do anything beyond providing constraints on the behavior of the various HTTP verbs? How would such constraints be encoded? A lot of food for thought here.

Lassen Volcanic National Park trip report

2008-08-05T11:38:00.000-07:00

We returned from Lassen Volcanic National Park late Sunday. Well, technically early Monday. Spent the day yesterday recovering. I'm not in decent hiking shape, and even the little hiking we did took its toll. That aside... Lassen is amazing! I got us a reservation at Butte Lake (we showed up on the wrong date, but that's another story...) more or less by accident. It was the first camping reservation I'd made, and the reservation web site is, well, lacking in user friendliness. Butte Lake is in a relatively remote north east corner of Lassen, inaccessible from within the park, off a gravel road. But there we find one of the most spectacular sites Lassen has to offer: the Cinder Cone. Bumpass Hell is great, but the scale and quality of Cinder Cone made it superior in my mind. Plus, you can hike to the top. We got to our campsite too late to attempt the hike, but we got close enough to really appreciate the spare beauty of the site. The Cinder Cone rises up from some impressive lava beds. I did of course take lots of photos, I'll post them when they're processed. Largely speaking, I feel we barely scratched the surface of the sites accessible from that corner of Lassen, and we'll have to return for a longer stay there some time.

Morning at Butte Lake was really amazing. It was cold when we woke, but nowhere near freezing. A couple of layers had me comfortable enough to take a trip out to the lakeside for some early morning photography, some of the best of the trip. We packed up and headed out to the main park area. We entered through the Manzanita Lake entrance, another wonderful sight. There we spotted a bald eagle! But I was too slow with my camera to make good of the opportunity. We stopped at the visitors center. I've decided the NPS has the best officials I've met, meeting them always leaves me happy. Got a few pointers for trails to take.

We first went up to Paradise Meadow. The trail was uninteresting to start with, but then as we climbed we found more and more wildflowers. The trail ran along a stream, and the end of the trail was in a large meadow surrounded by mountains. Our next trail was the Kings Falls. It is another short trail, goes down running along a stream, which cascades down some rocks. We initially thought those were the falls, but as awesome as they were, the falls were further along the way. The distance markers were a little confusing, we theorize that they stamped duplicates of certain signs and just decided to use all of them, even though they were a bit inaccurate. The falls go down many feet, but we can only see them from the top. So it is a bit difficult to fully appreicate them. On the return we went up a horse trail rather than along the cascades. The upper portion of the horse trail was quite wide open, very scenic.

After the Kings Falls trail we proceeded along the highway, climbing, climbing, climbing up to about 8000 feet. Right next to Lassen Peak. The peak looks quite doable, maybe next time we'll give it a shot. There's a rest stop with some food and water. Just past Lassen Peak is Helen Lake, one of two alpine lakes that are right by the roadside in Lassen. From there we went on to Bumpass Hell, just a few hundred feet further along. The trail is quite easy, runs along the sides of hills which challenged my fear of heights. Especially since my feet were not holding up so well. Bumpass Hell was other worldly. Anyone going to Lassen has no excuse for skipping out on this site, it is just that accessible.

From that high up we could also see the forest fires burning, and the smoke streaming out. The sight made quite an impression. I've captured some of it in photos.

Lassen is the highest I've been so far. I know, not that high. But we'll soon be going to the Eastern Sierras, to White Mountain, to see the bristlecone pines. We'll easily cross 10000 feet on that trip! I'm really looking forward to that trip.

As for photography, my new 24-105mm lens held up really nicely. The only problem with the lens is that the zoom drifts. I tend to wear the camera strap with the camera hanging down, and invariably the lens drifts out to 105mm. This is a bit disappointing. The expensive B+W polarizer turned out to be fantastic. Seems to lose less light than other polarizers I've used, even from B+W. Highly recommended. Using a tripod really brings out the best of the lens, otherwise even as good as the IS is on the lens, it still doesn't compare with the stability of a tripod. My best photos, morning at Butte Lake, were taken with a tripod. That is the only time I used a tripod. The difficulty with a tripod of course is that you have to carry it and set it up. This is difficult when you're trying to get through three trails, even short ones, through the course of the day. A good tripod, in other words, is virtually a necessity. Also, the 24-105mm is a good enough general purpose lens that I will try a different tack the next time: instead of carrying so much camera gear, carry a tripod instead. I didn't touch any of the other lenses I was hauling through the whole trip!

To the northwest corner!

2008-07-31T14:41:00.001-07:00

We're going to Lassen on Saturday. But I made an error in reservation, and sent us off to a night at Butte Lake. Accessible only by driving eight hours down a gravel road. At least it will be (relatively) secluded.

I am forgotten

2008-07-31T14:39:00.000-07:00

I feel as though I've been forgotten, working here in front of my computer. But is it really that I'm forgotten, or that I've forgotten how to be?

Space profiler needs profiling

2008-07-29T07:11:00.000-07:00

I struggled and failed against the Allegro CL 8 space profiler yesterday. I tried capturing a space profile for some of our software running on Windows. With only five seconds worth of data Allegro CL would chew up 300MB of heap in producing the profile. Needless to say there was nothing meaningful to be had there.

What I really want is to get visibility into which heap data allocated makes it to oldspace. I want to see what's making the image size grow. I'm not getting useful data from the space profiler, and I don't think I possibly could. Time profilers are much more useful in optimization, space profilers can't separate temporary allocations from those that get tenured.