A mate who sails my locals asked me if I could write a Android Phone app that measures the wind and tells him what to rig. This winter, I want to learn how to write Android phone apps. I figured this app would be a good learning exercise. I was wondering if there are any existing applications like this ?. If not, would people find this a useful tool ?

I did a quick google search. The existing phone apps related to Windsurfing are all GPS tracking apps. I couldn't find any related to rig reckoning. Could somebody verify this for me ?

Nb/ This will be a free to use app. To quote fractint- "Don't need money, Got money, Need admiration !"



Cheers J

A difficult proposition to get people to use.
Let's assume that you are able to measure the wind like these apps that make use of the mic appcrawlr.com/ios-apps/best-apps-wind-meter.
You will need the average wind, and the range of the gusts, type of sailing e.g. Flat water, waves, open ocean, the person's weight, board width, available sail sizes, cams or no, fins available, choppy or smooth, altitude and air temp at least.

Only about half of those can be entered beforehand so instead of rigging something and talking to your mates, you need to enter some stuff in your phone. I suspect most wouldn't bother.

I may sound like I'm just seagull-ing on your idea, but I discovered by writing an app previously for windsurfers to let each other know when and where they are going windsurfing, what size they were rigging so others at the same place could know what sizes are on the water - I was enthusiastic about it at the start but then I (and everyone else it seems) really couldn't be bothered with my phone once I was actually at the beach. You may have a different experience, this is just the way it turned out.

Select to expand quote

sav911 said..

Not at all, always keen for advice. I used to write a lot of GPL software in the 90's and early 2000's. What you mentioned is an old pitfall: Somebody gives you a great idea and they are really super keen to be a user of it. You develop it, and some time down the track when it gets developed, they are not interested in using it. Long story short: I know what you are talking about. In the commercial world, this isn't a problem. When you give away software, it is.

I need a good application as an exercise (it's hard learning an API without a useful application). If a few people are interested in this rigging reckoner (even given the above mentioned pitfall), I'll risk writing it. I'm deciding to make it fuzzy logic/formula based, or statistical based (or both). However, I am thinking of making it statistical. I've got a few ideas on how to implement it. Of course, it will need to be written for the impatient

The factors I will be using are: equipment details and configuration (user can preenter, group for easy selection, or enter them after the session, or put don't know/don't care if they are lazy), location (map selectable), water type, ocean/lake floor clutter, wind speed, wind direction, temperature, pressure (BOM/Seabreeze query, or measurement), water type, condition time (ie: seabreeze, trade wind, frontal etc), sailor type, sailor experience etc. The App will be written to memorise preentered data, and grow information about a location or a rig setup etc so the fields are pre-filled.

With statistical base, it's should be a few buttons before the session, and then a few buttons after the session. An alarm notification will prompt the user after session and ask them to give session rating out of 10. App will note condition(s) and what gear(s) they used. Over time, it will be able to statistically match a given session/location/date with gear. Of course, the Garbage-in-garbage-out rule applies if users get into the habit of using "don't care" values. The App will also have a means to exchange data so queries on other sailors can be done without needing to ask them (ie: they are not there).

I feel there are too many variables (skill level / conditions being the biggest). It's not uncommon for me to be sailing on a 8m sail with 73 cm board while another sailor is on a 6.2m witch a 62cm board. We are both achieving the same outcome and enjoyment, just a different approach.

after all the data entry the wind still has the same ability to change just as we hit the water. :)

I have an app called Quiver Ace on my iPhone. Sounds a bit like what you are proposing. Doesn't measure the wind, I use my old speed watch anemometer to check wind speed. Then refer to the app. You enter weight skill board type etc etc.
I find it to be pretty accurate and very useful personally.
Cheers, Brad.

First thing that came to my mind when i read the post was to make the app learn and become better the more you use it.

Start off with the user entering, their gear, weight, and skill level, and from that give them a suggestion on what to rig. Where it becomes smarter, is that after the session, the app asks "did you have a good sail?", user can answer yes, no was underpowered, no was overpowered. App figures out based on GPS what the wind was doing at local weather stations, and remembers it so that next time it gives you a better suggestions.

Obviously, this is no longer a simple app... haha

*edit* oops, just read your second post, seems like you are already thinking along the same lines.

If you are going to rely on learning from previous input, you'll have a bit of chicken - egg to make it provide good suggestions initially, to provide some value to the user, because they will only use an app that helps them. You may want to request data from other sites that capture windsurf info to seed your algorithms e.g the gps speed sites.

Thanks guys for your feedback. Looks like the wheel has already been invented (thanks for your find ballast and bhc), but I still would like to try my statistical idea. I suppose I will write it for myself. If it's useful, then I'll give it to a few mates at my local and see what they think... and take it from there with no expectations other than it being a Android learning exercise.

Good tip about the GPS tracking swoosh, and point noted sav911 - GIGO.

Waiting4wind: changing variables. I have an idea to deal with that problem. I'll see if it works.

Anyhow, here goes. You might hear from me again

J

I think you could run a natural language parser over some of the text entries in the gps team challenge session comments to extract wind strength, direction and what sail sizes were used. Find a couple of entries on www.gpsteamchallenge.com.au/ and paste here http://nlp.stanford.edu:8080/parser/index.asp

Then you can roll in the speed metrics for the person that posted and you can deduce that if you rig a 5.0 at Sandy Point on WSW you can expect to go 40+ kts and have 25kt alphas

Thanks sav911 for the idea

Great idea Jay but not sure it would get used much !
just think what someone like a "Hayden" would do with it......
"Which button do I press ??"
Have a crack anyway
good luck

If it can pick the right gear for ledge to lancelin race it will be all worthwhile. It needs a crystal ball function.

Select to expand quote

S018 said..

Yeah, thanks Dave . I'll definitely have to make it Hayden friendly if it has any hope of success, although he doesn't sail much now days.

Piv: Okay, I'll see what I can do

I've had a bit to do with citizen science / community engagement apps. I wonder if it would work if people noted what gear they were using after each sail, import wind data from Seabreeze or BOM or whatever. Rank the session between one and five stars.

I've now developed 80% of this app. I have given it to a few mates to test and now want to take a break from this app to work on other developments. They will decide if the app is worth continuing or "bush gate it". It's a statistical data driven tool, and my main worry is it's too much hassle to use for most windsurfers (as you said Ninjury). Anyway, it's been a good exercise to learn Android apps, and it's a new skill set I have now. Below are screenshots of the app:

Main screen:


Location list:


Location editor:


Session list:


Session editor:


Session editor:


Session editor:


Sesson editor: Note: The rating is key information, is it links conditions data with rigging data for a given session. The reckoner function will use the rating to match rigging with a given condition.. and this is all based on historical data you enter (or your mates data if your sailing style in the same as them. Later versions will be able to exchange data with your mates)

I'd say go ahead with it. It looks pretty slick on the layout already and I can tell you're having a blast with it already. Make it applicable for kiters and their equipment as well, as you could expand your audience. The kiting industry is huge, and wish the sailboarding industry was as large. I would seriously think about a patent. I know money is no object for you, but this is a great idea and should deserve compensation on your behalf if this is a success. Good luck and keep us informed.

Looks Good..
glad you went ahead with the development
Lets hope some of the boys get lot's of use out of it.
always good to learn new skills

Select to expand quote

bhc said..
Have a look at the following for sail size calculations for a given wind, level of experience and weight:

http://www.riggeek.com/gear-calculator/for-windsurfers

play.google.com/store/apps/details?id=org.bitpipeline.app.windsurfcalculator&hl=en

That 1st one reckons a 6.4m sail for me for slalom in 10kts..I wouldn't get moving!

Is it available on Google Play? Can you share the link? Would love to try it.