Well Steve. Thank you for your links and your help.
This will be a long description. (sorry, but i must explain it).
The main problem is this.
If you go to the field, without internet (in the middle of the mountains, a desert or in a delta, a littoral area) you will not have a computer or internet.
So, The windows, mac, linux versions of the apps, are a blocked option. I find many ways to do it, but not WITH THE PHONES or Tablets.
PLUS. I want to use the compass, take the data, store and then plot.
Maybe one by one, the pair of data i mean. Maybe not dozens of points (that means almost 12 points by *3 or *4 info per point).
Not. I only want to make a representation FOR AND IN THE FIELD.
Why?
One thing is measure in the field, and another the projection in the Desk or the Lab. And... I have a problem with the SUM of Error. From the statistical point of view, when you go FROM THE FIELD TO THE DESK, You carry a lot of error.
A REAL Example. I am from Argentina, i need to go to Brazil, take some samples and take some measurements. BUT, when i return, i recognize many of this measurements ARE WRONG. Maybe someone take it, and you are in a group, and they dictate the numbers. Maybe the compass was broken, maybe the number 3 of one man is an 8 and was by writen, maybe was distracted and the 87º in one side was not to the left, was to the right....
if I returned, i cannot go back, and take the samples AGAIN (all the data taken is corrupt, is bad). You cannot trust it. (maybe if you look to other side :/, but is not the point. If you find a big error, is sure there will be MORE.
Well. This things NOW... ARE A MESS, because no one control the ERROR of the System, and from the technic... BUT IF YOU MAKE A COMPASS APP, TAKE THE DATA, STORE AND SHARE THE POINTS... Well. The amount of ERROR reduce almost TO 0!!!!!!!!!! CERO!... well, not 0 because many of the devices could have a miss match. But, is almost in that region of total success.
You only MUST TO PAY ATTENTION TO THE MEASUREMENT WITH THE PHONE OR TABLET. Because all the other things ARE AUTOMATIC!. And you are NOT CARRYING ERROR to the analysis.
That's the reason of TRY TO MAKE AN APP LIKE THIS.
Some geologist still have analogical compass, paper notebook, pencil or pen. (if you miss them?)... If you miss the pencil or the pen, you must return?!!!! or if the compass get broken too.
If you go to the field with 10 students and the app is in all the phones ... Well. There will be 10 measurements very near one of each other. Not really different measurements. They could have some deviation, but NOT BIG ERRORS.
I have my app, of compass, store the data, share data as screenshot (as a graph) and as a csv of the list of the measurements. BUT, i want to add the STEREOPLOTTING section.
For this problem... Seems i must learn Python, manage mplStereonet package and learn Kivy or other Gui tool or library, and port to Android.
BUT was almost done... And i need TO ADD a section to my app, in this case, i must to RE-MAKE ALL for this problem.
Well, That's my problem, and i think the problem of many geologist. Go to the field, trust in the tool, and as an academic tool, be good to represent the reality (not a cartoon).
I FEEL (and it's my opinion), WE, the geologist and other earth related science, produce some cartoons, because the tools ARE OBSOLETE. Even when we the Geologist have tons of new technology from LIDAR to sat images for (GIS), IN THE FIELD IS ANOTHER THING. In some fields, we use Obsolete tools. They work fine, but they carry a lot of problems and errors.
Steve. Thank you for reading my academic problem, and for helping me. (i can share with time a project related to recognize kind of soil with an IA), because we can recognize with a book (yes, a book with holes for recognize soils!!!! in this days!!!!.
But, for this, the principal problem i try to solve is the problem in the eyes of the Daltonics, they can't recognize the difference of colors.
And is very well documented, the woman, can characterize more colors than man. So. FOR RECOGNIZING, i make a tool.
The tool take a capture with the camera, and shows the colors similar to the a scheme. YOU as Geologist, MUST TO GET THE CHOICE. Because is not for an IA, the IA cannot learn of geology, and extrapolate choices in the field. And say, is this soil or ANOTHER... Even the daltonics geologist have a problem with the eye, they KNOW what kind of soil, is suitable for each zone they GO.
Again. Thank you for your help, i will continue searching how to improve my app for stereo plotting.