I am excited about this and really want to share it with my ST friends. My first publicly-available iPhone application is now available in the iTunes store! It is called “Altidude”, and it does altitude conversion of running times. It costs $1.99, and the direct link to purchase it in the store is: http://phobos.apple.com/...oftware?id=310277897
I can already hear the excitement in your voice as you say, “WHA?” Here is how it works:
It takes as input your current altitude, the distance you ran in one of four categories, and your time. Using standard conversion equations, it returns an equivalent sea level time. If your iPhone is one of the newer 3g models, it determines your altitude automatically using the built in GPS.
It does not account for individual variation in how people respond to being at altitude, so if you’ve found in the past that other altitude → sea level time conversions are not very accurate for you, this probably won’t be much better. I would love to have any suggestions on how I might accomplish that level of individualization, though!
I would also love to have any feedback on how it works for you (or doesn’t work for you), and additional features that would be useful.
Also WHOOOO I had 4 sales over the weekend, if any of them was a ST’er, thanks!
So if I currently live at sea level, will it tell me how much I’ll suck at altitude?
Love the name, btw…
It converts from any altitude, but it only converts to sea level. There’s no technical reason for that, though. I just thought it would be simpler to use that way. Would that be interesting information to have? “You ran 5k in 15 minutes at sea level … at 10000 feet, it would take you 18 minutes” or whatever. I wonder how high up you could go and still have the conversion be accurate.
Hmmm. Well, I’m off to find a track above 20,000 feet!
so in your research for this, did you get some sense for accuracy of the GPS receiver for calculating elevation gain and loss? I bought a Garmin Forerunner 305 recently, and although I like it, the elevation data it provides seems out of whack. The cumulative numbers I am seeing seem excessive so really curious how accurate these lower end gps receivers really are…
It’s king of interesting that run speed increases for short distances up to about 7000’ in altitude before the lack of oxygen overtakes the reduction in air density.
Being able to convert between any two altitudes would be useful instead of just down to sea level. This would be better for those us that train at sea level but may race at altitude.
Plugging in several known times and altitudes and having the software interpolate for a new altitude would also be nice.
Although, I have to admit I first read the title as “iPhone app for ATTitude conversion”, and I was all like SWEET! and like stuff, and then you were like “oh noes, altitidue”, and I was like bummed.
If you could write one for attitude conversion, I’d buy an iPhone just to be able to run it.
A little bit … the receiver reports an error level along with its position. In my limited experience it’s quite accurate as far as it claims to be - that is, if it says “Altitude = X with Confidence 100m” then it’s almost definitely within 100m. The tricky thing is deciding when a fix is “good enough”. The iPhone’s built in GPS runs the battery down really fast if it’s on continuously (and I assume the same is true for other low end GPS receivers) so a lot of navigation programs will, for instance, just turn it on at specific intervals to try to get a position. You can also look for positions until you find one that’s accurate enough , or use a hybrid approach.
What I did for Altidude is this:
Check to see if “location services” is enabled at all (you can turn it off in preferences), and if it’s not, disable the “Get GPS location” button.
If “Get GPS location” is tapped, start looking for a position fix.
Every time a new fix is acquired, if it is more accurate than the current fix, update the current fix.
If the current fix has a confidence of 5 meters or less, stop looking for more position fixes and use that.
If 20 seconds elapse, stop looking for more position fixes. If the accuracy is not within 100 meters, show an error message (“Please enter altitude manually”), otherwise show the best position obtained.
I don’t actually have a GPS-equipped phone, so my buddy Pete (who did all of the graphics, thanks Pete!!) had to debug it remotely. That was a kick
It’s king of interesting that run speed increases for short distances up to about 7000’ in altitude before the lack of oxygen overtakes the reduction in air density.
Yes … and I should mention that this program does not handle sprints correctly, as I haven’t the faintest idea what that conversion might be. It does address the relative aerobic/anaerobic demands of 1500m vs 5000m races (giving slightly less of a percentage speedup to shorter events than longer ones), but it will not give correct results for, eg., an all out 400.
Being able to convert between any two altitudes would be useful instead of just down to sea level. This would be better for those us that train at sea level but may race at altitude.
Plugging in several known times and altitudes and having the software interpolate for a new altitude would also be nice.
That sounds like a cool idea, I will look in to it. Especially the ability to plug in known times and altitudes, that sounds like it would give results that were much more tailored to an individual. Thanks!
Clearly! As MarkyV declares (ad nauseum), Boulder is the best place in the world and must be inhabited by the most awesome people too! We California mtn people are unfortunately not so awesome.
This app is clearly not an equal opportunity mountain people app. Why? Because Louisiana mountain people need the conversion from below sea-level to sea-level. This app is blatantly showing your elitist view of Boulder mountain people.
This app is clearly not an equal opportunity mountain people app. Why? Because Louisiana mountain people need the conversion from below sea-level to sea-level. This app is blatantly showing your elitist view of Boulder mountain people.
It never occurred to me until this moment to test for negative altitudes, but it actually does convert from below sea level to sea level.
Although, I have to admit I first read the title as “iPhone app for ATTitude conversion”, and I was all like SWEET! and like stuff, and then you were like “oh noes, altitidue”, and I was like bummed.
If you could write one for attitude conversion, I’d buy an iPhone just to be able to run it.
Although, I have to admit I first read the title as “iPhone app for ATTitude conversion”, and I was all like SWEET! and like stuff, and then you were like “oh noes, altitidue”, and I was like bummed.
If you could write one for attitude conversion, I’d buy an iPhone just to be able to run it.
John
If I figure out how to do that, I’ll PM you a beta copy
