Wednesday, November 12, 2008

Too hard! Too hard!

I have a long list of calculations that I want to add to Calctool. I still want to keep up the expansion, and am willing to ad calcs on demand, but unfortunately it's hard to find the time. However, there are some calcs that it really does look like may never make it...
Too difficult
Some calculations are extraordinarily hard to do accurately, even though they often appear simple at a glance or quick thought. When you start to go deep down into them, you find a lot of details that quickly make your life a misery. Calctool calculations are generated from "a little bit of Javascript", not a mountain of programming. Differential equations and the like are out for me!
Into this category fall items such as Mie scattering, the Chinese calendar, and sextant sight reduction calculations.
Numerical solutions
Calculations that require numerical integration or large lookup tables to perform are also too much hard work to program (unless some kind benefactor could donate Javascript). Sorry, but no integration of probability distributions, or estimation of the three-body problem, in the near-future.
Mind-numbing for my advanced years
In the past, in my young mathematical prime, I could derive equations for anything you could care to mention. Recently however, I have been stumped by some worryingly trivial problems. That's why, for example, there's no calc for the elastic collision of spheres.
Too much like programming
I'm no programmer, so even some simple calculations are outside my ability. Things that I'm sure are easy, like the manipulation of times and dates, and having textual inputs and outputs, are largely down to other volunteers to produce.

Tuesday, July 15, 2008

Least popular calcs

It's easy enough to browse through CalcTool and take a look at the most popular calcs. However, I started wondering which are the least popular. Which calcs are just not getting used, and can I work out why? So I took the database in hand and came up with a bottom ten.
And in the last two places are the financial calculations that determine how much you can afford to borrow and how large a repayment you can expect on a mortgage or loan. I would have thought that these would be useful, particularly in the current economic climate. Mind you, maybe everyone already knows that they can't afford their mortgage, and nobody is interested in getting a new one. However, my guess is that there are already a lot of financial wizardry sites out there with calculators of their own, and money to burn on SEO. To put it another way, people want these calculations, but they don't end up finding them on CalcTool.
The real surprise is the dire performance of astronomy calcs, in particular those determining parameters of orbits. Circular orbits, satellites of the Earth, and planetary orbits all have calcs... that reside firmly in the bottom ten. This lack of interest I can't explain, and I'd be interested to hear any ideas on the subject.
Many of the rest are less surprising, being rather simple, boring or obscure. Let's face it, who goes to the web to calculate a logit function? Gravity, parallel plate capacitors and drug dosage all get a place here, as does the calc which finds how many tiles you need  to cover your floor or wall. So if you're caught short on that front, don't come running to me for sympathy.

Tuesday, June 10, 2008

Back to the calcs

Well it looks like it's been a month since the calc addition rate declined to just about zero. The large site upgrade took a lot of focused effort, and even since then there's been a certain amount of tidying up in the aftermath. However, I'm pleased to say that that is done with, and it's time to get back to the calcs.
All the category pages now sport pictures, which I hope makes them a little more user-friendly. Here's a few examples for your pleasure. The extra pages are also all now in line with the design principles of the main site, and they also have some pictures to ease things on the eye. On the other hand, I'll freely admit that some are far from optimal, so I'm happy to take any advice for improvement. A few other improvements are also finalized, including improvements to the navigation bar and the links in general, hopefully helping people move around the site more easily. 
The biggest disappointment right now is the forum, which is still waiting to take off. For some reason people don't want to sign up, even for MyCalcTool, despite the advantages of a favorites list and fewer ads. I'll have to think about that one. We also seem to be leveling off at around 100 visitors per day which, although it makes the project worthwhile, is somewhat less that I think the site deserves. Another one for thought, although to be fair, it's not like I've done any active promotion.
So maybe it's time for the CALCTOOL OFFICIAL LAUNCH. I'm just about happy with the features, stability, and number of calcs (maybe a few more are needed...). It could be happening at an internet near you, very soon.

Monday, May 19, 2008

General upgrade

Today we've made a general upgrade live, which brings new features to CalcTool, most importantly "MyCalcTool", which allows users to have a favorites list to keep the calcs they need the most. We've also taken this opportunity to improve the "new" and "popular" pages with an automatic logging and updating script, and to bring the other static pages properly into line with the site design. The changeover isn't 100% complete yet, so please excuse any teething troubles, old links, bad design, and missing features for the moment. Any problems, please let us know at the forum

Another thing that has been vastly improved is our standards compliance. When I checked a few of our pages through a validator last week, I was somewhat horrified to find upwards of 500 errors on most of the pages. To be fair, most of them were severe pedantry on the part of the validator, but many were very real. Really this is testament to the ability of modern browsers to cope with bad code, since we never noticed a thing. Anyway, to cut a long story short, almost all of the errors have now been fixed, with most of the pages validating  100% cleanly (including the css, if you must know).

Finally, we now have over 200 calcs in the database.

I think we can just about call this "CalcTool 1.0", although there may still be more goodies at some point in the future... you never know.

Tuesday, May 13, 2008

Announcing CalcTool mobile

I'm pleased to say that with a bot of hacking at the CalcTool code, I've been able to create a secondary version that is more suitable for mobile devices. Most of the images and tables are removed, and things are squeezed up horizontally to get it comfortably into a 200 pixel-wide window. Naturally there are casualties, most notably the textual notes and images that come with a calc in the full-sized version. It's also a little more tricky finding what you're looking for, with the "related" sections and navigation panes removed. The underlying code is the same as for "regular CalcTool", so you still need a decent modern browser with good css and javascript handling. Still, if you know the score and you know where you're going, then it will make a quick calculation on the move possible. Give it a go - it's very rough for the moment, but a few helpful comments can help work out the wrinkles.

Sunday, May 4, 2008

Time to start calculating!

Sometime in the middle of February, a germ of an idea for a website raised its head. By now, CalcTool contains getting on for 200 different calcs, and is getting around 50 users a day. OK, that's still not much, but it's enough of a start for it to have been worthwhile, and something to build on.

So, what is it? CalcTool aims to make simple everydays calculations easy for everyone. No more looking up formulae, messing around with unit conversion, or searching for a calculator. The idea is that for anything you want to calculate, for example the day of the week you were born on, or the reflection from a window, you look up the relevant "calc" page, tell it what you know, and get the answer out. It helps you out with a diagram is necessary, gives handy hints and notes, and lets you know (to some extent at least) how the calculation is performed. It also makes some attempt to do away with esoteric language, so that if you want to know (for some reason) the volume of water flowing through a river, you can do it without needing to have heard of the Manning equation, or knowing what "head loss" and "Q" are.

Probably the most powerful (and simple)  feature of CalcTool is the built-in unit conversion menus attached to most input and output boxes, that allow your measurements and answers to come in any form you are comfortable with. This also leads to a while bunch of very convenient unit conversion calcs

Anyway, enough of the blatant advertising. I want to use this blog space to document some of the latest calcs I'm proud of or interested in, as well as upcoming changes and development issues.  I have no idea how often I'm going to post - it may depend to some extent on how many people seem to be listening.