Skip to main content

The humble parameter

As any software engineer will know, it is often easier and better to design a system that is too general for the particular task at hand and then to govern the actual behavior with a parameter. At one extreme you get sort functions with the comparator supplied as a parameter to the sort. At the other extreme you get entire policy-based frameworks where the parameters that govern the system are represented as rules.

A similar phenomenon occurs in mathematics: it is often simpler to solve a more general problem than to solve the particular problem. The more general solution is often parameterized in such a way that the particular solution falls out of the general case.

Recently, I learned of a use that Nature has put to the parameter, it seems that Finches' beaks may also be governed by one or two genes (BMP4) which show up in many wildly different animals (Finches, fish, butterflies, ...). I would suggest that what is going on here is that we have a general mechanism (the HOX genes) with a system of parameterization that is easily modified.

There seems to be a general principle at work here -- that the pattern of having a general mechanism tied to a parameter to give particular instances -- applies to many things and in many areas of the world. Perhaps this is one of those natural joints that philosophers love to carve.

Perhaps a Math grad student would be interested in designing an algebra of parameters?
Labels:

Popular posts from this blog

Comments Should be Meaningless

This is something of a counterintuitive idea: Comments should be meaningless What, I hear you ask, are you talking about? Comments should communicate to the reader! At least that is the received conventional wisdom handed does over the last few centuries (decades at least). Well, certainly, if you are programming in Assembler, or C, then yes, comments should convey meaning because the programming language cannot So, conversely, as a comment on the programming language itself, anytime the programmer feels the imperative to write a meaningful comment it is because the language is not able to convey the intent of the programmer. I have already noticed that I write far fewer comments in my Java programs than in my C programs.  That is because Java is able to capture more of my meaning and comments would be superfluous. So, if a language were able to capture all of my intentions, I would never need to write a comment. Hence the title of this blog.
Read more

Action at a distance

We are currently writing our first draft of the SOA Reference Architecture. Everyone is very busy doing their bit. My current section is on the Real World Effect of using a service. The RA is really an abstract architecture: we are not focusing on things like SOAP, or any of the other 60+ Web service specifications out there. We are trying to get at the essence of makes SOA special and how it can be made to work. It is a pretty basic aspect of services that we are trying to get something to happen: buy a book, get the weather forecast whatever. In other words: its action at a distance. I am communicating with you in the hope that we can get some mutual benefit. This already distinguishes SOA from the Web, whose basic abstraction is to acquire a representation of a resource will be rendered locally for human consumption. Actions are not inherently about representations, they are about changing the world - one book at a time. Action itself is a very difficult concept to get hold of. It ...
Read more

Organizing principles for services

One of the questions that comes up from time to time is how to define your services. This has come up for me in two independent fora: within the OASIS Service Oriented Architecture work and in the context of human provided services, for example at Genietown . In the work on the SOA Reference Model we decided that "services are the mechanism by which needs and capabilities are brought together"; i.e., its about needs and capabilities to satisfy those needs, and the access mechanism. However, this still begs the question somewhat. In the domain of human services, where the services are things like "building a home", "walking the dog", "taking care of my elderly parents"; it gets even fuzzier. Sometimes a service seems to organized around the person offering the service, for example, an architect, or a doctor. Sometimes the service is organized around a particular kind of product, such as doors or skylights. At other times, the service is organize...
Read more