[GraphHopper] Fwd: Re: instruction too early

[Peter]

I've created an issue for this:
https://github.com/graphhopper/graphhopper/issues/335

Peter

On 17.02.2015 16:48, Laura Barroso wrote:
> Yes, that will solve my issue, Backward search will be required too.
>
> -----Mensaje original-----
> De: Peter [mailto:graphhopper at gmx.de] 
> Enviado el: martes, 17 de febrero de 2015 10:43
> Para: graphhopper at openstreetmap.org
> Asunto: Re: [GraphHopper] Fwd: Re: instruction too early
>
> ok. So what you would need some method like this:
>
> currentInstruction = find(lat, lon, maxDistance, previousInstruction)
>
> which can be called several times (and is cheap&fast) and only searches e.g. forward for the closest instruction? Would this solve your issue?
> Or would 'backward' search also be necessary as a user could go far off the route?
>
> Peter
>
>
> On 17.02.2015 16:32, Laura Barroso wrote:
>> well,yes, I can probably do that, but I was thinking that if my 
>> current location is near to one of the points that holds the 
>> instruction then I will miss it, am I right?...however will do your suggestion.Thanks.
>> My usecase is guide the user depending on the gps current location and 
>> the route.
>>
>>> if you find once the next instruction why would you need to iterate 
>>> over all points, why not just take the first of this instruction 
>>> (getFirstLat
>>> etc) and check the distance? what is your usecase?
>>>
>>> Peter
>>>
>>>
>>> On 17.02.2015 16:15, Laura Barroso wrote:
>>>> you mean something like this?
>>>> DistanceCalc distCalc = Helper.DIST_EARTH;
>>>> 			distCalc.calcDist(instruction.getPoints().getLat(0),
>>>> instruction.getPoints().getLon(0),					 currentLocation.getLatitude(),
>>>> currentLocation.getLongitude())
>>>>
>>>> but still will have iterate over all the points inside the 
>>>> instruction...
>>>> is there any better way????
>>>>
>>>>
>>>>> Laura,
>>>>>
>>>>> why not find the next instruction and only display it if the 
>>>>> current location is close to it? No need to do unnecessary find() calls.
>>>>>
>>>>>> until the max distance between
>>>>>> one of the edges and the current position is right, even is that 
>>>>>> mean that the user don't get any instruction at all
>>>>> Why not specify the allowed maximum distance to the route in the 
>>>>> find method appropriately?
>>>>>
>>>>> Regards,
>>>>> Peter
>>>>>
>>>>>
>>>>> On 17.02.2015 14:43, Laura Barroso wrote:
>>>>>> oh boy, so that's what's happening...this is not good for me, I'm 
>>>>>> not interested in knowing the next instruction until the max 
>>>>>> distance between one of the edges and the current position is 
>>>>>> right, even is that mean that the user don't get any instruction 
>>>>>> at all because he don't get close enough to them. ok, Thanks a lot 
>>>>>> for the clarification, now everything gets more sense.
>>>>>> Thinking a good approach maybe override instructionList class in 
>>>>>> order to modify this behavior to suit my needs. Second approach: 
>>>>>> compute everything twice, one the instructionlist(in the find 
>>>>>> method) and the second on my method...
>>>>>>
>>>>>>> Hi Laura,
>>>>>>>
>>>>>>> I took a look at InstructionList.find() and actually found some 
>>>>>>> inconsistent behaviour:
>>>>>>> https://github.com/graphhopper/graphhopper/issues/331
>>>>>>>
>>>>>>> Nevertheless I don't think this is the reason for the problems 
>>>>>>> you described.
>>>>>>>
>>>>>>> Maybe to avoid misunderstandings, the find(lat, lon, dist) method 
>>>>>>> is supposed to work as following:
>>>>>>> Given lat,lon find the closest point on the route. If lat,lon is 
>>>>>>> not more than than dist away from the route, then it yields the 
>>>>>>> upcoming instruction (even if this instruction is a lot further 
>>>>>>> away than dist).
>>>>>>>
>>>>>>>> Easy: any point in Havana I have test routes in Miramar, Vedado 
>>>>>>>> and Guanabacoa, note those are like areas that are not close to 
>>>>>>>> each other(at list Guanabacoa from the rest), the last point 
>>>>>>>> that I test was:
>>>>>>>> START:  latitud: 23.12529533541739 longitude: -82.41401873360883
>>>>>>>> END: latitud: 23.124871881707463 longitude: -82.4237889156866 
>>>>>>>> The route that I create was on foot, for android purpose. Thanks!
>>>>>>>>
>>>>>>>>
>>>>>>> To find the reason for your exact problem, it would help a lot if 
>>>>>>> you can also give me lat, lon coordinates for which you don't get 
>>>>>>> any instruction or the instruction within wrong distance.
>>>>>>>
>>>>>>> Cheers,
>>>>>>> Jan
>>>>>>>
>>>>>>>>> Hi Laura,
>>>>>>>>>
>>>>>>>>> thanks for the clarification. i will take a look into this, but 
>>>>>>>>> it would be helpfull if you can provide me start and end point 
>>>>>>>>> of the route, as well as one or two points where there is a 
>>>>>>>>> wrong instruction or one missing.
>>>>>>>>>
>>>>>>>>> Jan
>>>>>>>>>
>>>>>>>>>> Hello, thanks for your reply, I was not referring to that 
>>>>>>>>>> issue but it is quite similar to was happen to me... however I 
>>>>>>>>>> know that graphhopper generate all the instructions for the 
>>>>>>>>>> route, I check it out every time.
>>>>>>>>>> The problem is that it gives me the wrong instruction at the 
>>>>>>>>>> wrong time.
>>>>>>>>>> The sniped code you see is part of the class that overrides 
>>>>>>>>>> MyLocationOverlay, on the onLocationChanged method.
>>>>>>>>>> I tell graphhopper to give me the next instruction in this 
>>>>>>>>>> piece of
>>>>>>>>>> code:
>>>>>>>>>> Instruction instruction = il.find(location.getLatitude(), 
>>>>>>>>>> location.getLongitude(), 2); il is the InstructionList that is 
>>>>>>>>>> created as part of the route, I pass it to the class and every 
>>>>>>>>>> time that location changes I check if there is anything to say 
>>>>>>>>>> to the user.
>>>>>>>>>> Hi Laura,
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>> Hello everyone: I notices that graphhopper is giving me the 
>>>>>>>>>>> instructions too early and sometimes it wont even give me 
>>>>>>>>>>> anything, I think I read about an issue pointing that but now 
>>>>>>>>>>> is close...
>>>>>>>>>> maybe you refer to this issue
>>>>>>>>>> https://github.com/graphhopper/graphhopper/issues/94 regarding 
>>>>>>>>>> missing instructions?
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>> I override MyLocationOverlay class, and this is my code:
>>>>>>>>>>> @Override public void onLocationChanged(Location location) { 
>>>>>>>>>>> super.onLocationChanged(location);
>>>>>>>>>>> if (lastLocation == null || location != lastLocation) { 
>>>>>>>>>>> lastLocation = location; if (il != null) { Instruction 
>>>>>>>>>>> instruction = il.find(location.getLatitude(), 
>>>>>>>>>>> location.getLongitude(), 2); if (instruction != null && 
>>>>>>>>>>> instruction !=
>>>>>>>>>> lastInstruction) {
>>>>>>>>>>> lastInstruction = instruction; String text =
>>>>>>>>>> lastInstruction.getTurnDescription(esTR);
>>>>>>>>>>> Toast.makeText(context, text,
>>>>>>>>>> Toast.LENGTH_LONG).show();
>>>>>>>>>>> if (tts != null) { tts.speak(text, TextToSpeech.QUEUE_FLUSH, 
>>>>>>>>>>> null); } } } } }
>>>>>>>>>> I would take a look into this, but I don't understand yet 
>>>>>>>>>> where exactly your code hooks into the GraphHopper Code. I do 
>>>>>>>>>> not see any LocationOverlay class, but maybe you can point me 
>>>>>>>>>> there with a github link.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>> Note that it suppose to give me the instruction with at list 
>>>>>>>>>>> 2 meters of distance, last time I check it gave me the 
>>>>>>>>>>> instruction with at list 5 meters of distance in the first 
>>>>>>>>>>> edge...the next turn wont dispatch anything at all...what 
>>>>>>>>>>> could be happening? My start point now is branch "issue 314" 
>>>>>>>>>>> since I haven't being able to download the complete 
>>>>>>>>>>> repository(problems with my connection).
>>>>>>>>>>> any
>>>>>>>>>>> help will be appreciated.
>>>>>>>>>> Cheers,
>>>>>>>>>> Jan
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>