Re: [android-developers] Please help me with calculating direction from point A to B
I'm really not understanding how to go with this... I've been reading and reading.. I can find all kind of algorithms.. I can find a haversin algorithm that points me to the correct direction if my device is pointing north.. but the needle is static... so if i change the device orientation the measure is incorrect... and I know this happens because I'm not using device's sensor values like azimuth, pitch and roll.. oh god.. 2 weeks on this.. I'm just desperate now. On Sep 18, 2010, at 10:29 AM, Kostya Vasilyev wrote: Pedro, If I understand you correctly, you are having difficulties with the device's orientation. The bearing angle seems to be computed in the horizontal plane. If you wish to adjust for the device's orientation, you need to concatenate it with the bearing angle. Google for quaternions. This is a (relatively) simple math technique to work with rotations the same way you can work with vectors: add / subtract, interpolate. -- Kostya 18.09.2010 0:56, Pedro Teixeira пишет: Hi everyone... I'm back with the same issue for the last couple of days… I'm trying to create a compass for my application BUT the difference is that, instead of having a line always pointing to north, I want this line to point for a specific point. I've been trying dozens of algorithms and nothing works.. I've finally found one that points me exactlly to the point I want.. BUT it doesn't move if I change the position of the device which is my objective.. basicly, what I want is that no matter the direction I'm using my device.. the line always point me to the point (picLatitude,picLongitude)… I understood that for the line to move, I can't use static variables… I need to use the values offered by the onSensorChanged(SensorEvent event). This are the data I have available: event.values[0]: azimuth, rotation around the Z axis (device in relation to north, 0º) event.values[1]: pitch, rotation around the X axis event.values[2]: roll, rotation around the Y axis mLatitude: device current latitude gottern from GPS (variable) mLongitude: device current longitude gotten from GPS (variable) picLatitude: static picture latitude established previously picLongitude: static picture longitude established previously distance: distance in Km from device to the picture calculated previously And this the formula that works correct, and gives me the correct angle.. ( BUT IT DOESN'T USE ANY OF THE SENSOR DATA SO THE LINE COMPASS DOESNT MOVE): double dLong = picLongitude - mLongitude; double y = (Math.sin(dLong) * Math.cos(picLatitude)); double x = (Math.cos(mLatitude) * Math.sin(picLatitude) - Math.sin(mLatitude)*Math.cos(picLatitude)*Math.cos(dLong)); double angleDegreesWrongRange = Math.abs(Math.toDegrees(Math.atan2(y, x))); float angleDegrees = (float) ((angleDegreesWrongRange+360) % 360); myCompass.updateDirection(angleDegrees); I got this bearing formula from this website: http://www.movable-type.co.uk/scripts/latlong.html Can someone please help me with this? I've try adding, subtracting… the azimuth.. I've tried with the others.. seriously at this point I'm just demoralized.. Thank you in advance -- Kostya Vasilyev -- WiFi Manager + pretty widget -- http://kmansoft.wordpress.com -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en Pedro Teixeira www.pedroteixeira.org -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
Re: [android-developers] Please help me with calculating direction from point A to B
this sounds trivial to me. Just compensate the error that is introduced by not actually pointing the device north by subtracting that error from your arrow's pointing angle. No need to change any algorithm, just compensate for the dude, you're holding it wrong -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
Re: [android-developers] Please help me with calculating direction from point A to B
I've tried it. Adding and subtracting the value: event.values[0], which is actually my Azimuth in degrees returned by the sensor. But the orientation is off! .. The algorithm gives the Correct value, but it doesn't move because there's not sensor variables involved.. so if I subtract the error it points in the wrong direction On Sep 22, 2010, at 10:08 AM, Christian Buchner wrote: this sounds trivial to me. Just compensate the error that is introduced by not actually pointing the device north by subtracting that error from your arrow's pointing angle. No need to change any algorithm, just compensate for the dude, you're holding it wrong -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en Pedro Teixeira www.pedroteixeira.org -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
Re: [android-developers] Please help me with calculating direction from point A to B
Basicly, if my device is pointing the wrong direction. I can't see the value.. because the arrow is static. The arrow is always static if I don't use any of the sensor values. On Sep 22, 2010, at 10:08 AM, Christian Buchner wrote: this sounds trivial to me. Just compensate the error that is introduced by not actually pointing the device north by subtracting that error from your arrow's pointing angle. No need to change any algorithm, just compensate for the dude, you're holding it wrong -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en Pedro Teixeira www.pedroteixeira.org -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
Re: [android-developers] Please help me with calculating direction from point A to B
Pedro, I think you should learn something about the way direction (and orientation) is specified in computer programming. http://en.wikipedia.org/wiki/Yaw,_pitch,_and_roll http://en.wikipedia.org/wiki/Euler_angles http://en.wikipedia.org/wiki/Rotation_representation_(mathematics)#Rotation_matrix_.E2.86.94_Euler_angles I believe that Android orientation sensors work this way. Now about the compass There are two ways you can think about this: First, take the value you get from the algorithm and make it into a vector in 3D space (i.e. think of the arrow you're going to draw to indicate direction). Then: One: Compute the device's orientation matrix using sensor data. Take the inverse of this matix, and multiply the arrow vector by this matrix. Two: Compute the device's orientation matrix using sensor data. Rather than interpreting it as a rotation matrix, think of it as defining a plane in space (aligned with the device's screen). Then project the arrow vector onto this plane, in the plane's coordinates. You might want to start with compensating just for the vertical axis (the device's rotation from the true north direction), it might be enough. -- Kostya 22.09.2010 13:02, Pedro Teixeira пишет: I'm really not understanding how to go with this... I've been reading and reading.. I can find all kind of algorithms.. I can find a haversin algorithm that points me to the correct direction if my device is pointing north.. but the needle is static... so if i change the device orientation the measure is incorrect... and I know this happens because I'm not using device's sensor values like azimuth, pitch and roll.. oh god.. 2 weeks on this.. I'm just desperate now. On Sep 18, 2010, at 10:29 AM, Kostya Vasilyev wrote: Pedro, If I understand you correctly, you are having difficulties with the device's orientation. The bearing angle seems to be computed in the horizontal plane. If you wish to adjust for the device's orientation, you need to concatenate it with the bearing angle. Google for quaternions. This is a (relatively) simple math technique to work with rotations the same way you can work with vectors: add / subtract, interpolate. -- Kostya 18.09.2010 0:56, Pedro Teixeira пишет: Hi everyone... I'm back with the same issue for the last couple of days… I'm trying to create a compass for my application BUT the difference is that, instead of having a line always pointing to north, I want this line to point for a specific point. I've been trying dozens of algorithms and nothing works.. I've finally found one that points me exactlly to the point I want.. BUT it doesn't move if I change the position of the device which is my objective.. basicly, what I want is that no matter the direction I'm using my device.. the line always point me to the point (picLatitude,picLongitude)… I understood that for the line to move, I can't use static variables… I need to use the values offered by the onSensorChanged(SensorEvent event). This are the data I have available: event.values[0]: azimuth, rotation around the Z axis (device in relation to north, 0º) event.values[1]: pitch, rotation around the X axis event.values[2]: roll, rotation around the Y axis mLatitude: device current latitude gottern from GPS (variable) mLongitude: device current longitude gotten from GPS (variable) picLatitude: static picture latitude established previously picLongitude: static picture longitude established previously distance: distance in Km from device to the picture calculated previously And this the formula that works correct, and gives me the correct angle.. ( BUT IT DOESN'T USE ANY OF THE SENSOR DATA SO THE LINE COMPASS DOESNT MOVE): double dLong = picLongitude - mLongitude; double y = (Math.sin(dLong) * Math.cos(picLatitude)); double x = (Math.cos(mLatitude) * Math.sin(picLatitude) - Math.sin(mLatitude)*Math.cos(picLatitude)*Math.cos(dLong)); double angleDegreesWrongRange = Math.abs(Math.toDegrees(Math.atan2(y, x))); float angleDegrees = (float) ((angleDegreesWrongRange+360) % 360); myCompass.updateDirection(angleDegrees); I got this bearing formula from this website: http://www.movable-type.co.uk/scripts/latlong.html Can someone please help me with this? I've try adding, subtracting… the azimuth.. I've tried with the others.. seriously at this point I'm just demoralized.. Thank you in advance -- Kostya Vasilyev -- WiFi Manager + pretty widget -- http://kmansoft.wordpress.com -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en Pedro Teixeira www.pedroteixeira.org -- Kostya Vasilyev -- WiFi Manager + pretty widget -- http://kmansoft.wordpress.com -- You received
Re: [android-developers] Please help me with calculating direction from point A to B
Well.. I'm guessing it's to hard or impossible then.. :/ On Sep 17, 2010, at 9:56 PM, Pedro Teixeira wrote: Hi everyone... I'm back with the same issue for the last couple of days… I'm trying to create a compass for my application BUT the difference is that, instead of having a line always pointing to north, I want this line to point for a specific point. I've been trying dozens of algorithms and nothing works.. I've finally found one that points me exactlly to the point I want.. BUT it doesn't move if I change the position of the device which is my objective.. basicly, what I want is that no matter the direction I'm using my device.. the line always point me to the point (picLatitude,picLongitude)… I understood that for the line to move, I can't use static variables… I need to use the values offered by the onSensorChanged(SensorEvent event). This are the data I have available: event.values[0]: azimuth, rotation around the Z axis (device in relation to north, 0º) event.values[1]: pitch, rotation around the X axis event.values[2]: roll, rotation around the Y axis mLatitude: device current latitude gottern from GPS (variable) mLongitude: device current longitude gotten from GPS (variable) picLatitude: static picture latitude established previously picLongitude: static picture longitude established previously distance: distance in Km from device to the picture calculated previously And this the formula that works correct, and gives me the correct angle.. ( BUT IT DOESN'T USE ANY OF THE SENSOR DATA SO THE LINE COMPASS DOESNT MOVE): double dLong = picLongitude - mLongitude; double y = (Math.sin(dLong) * Math.cos(picLatitude)); double x = (Math.cos(mLatitude) * Math.sin(picLatitude) - Math.sin(mLatitude)*Math.cos(picLatitude)*Math.cos(dLong)); double angleDegreesWrongRange = Math.abs(Math.toDegrees(Math.atan2(y, x))); float angleDegrees = (float) ((angleDegreesWrongRange+360) % 360); myCompass.updateDirection(angleDegrees); I got this bearing formula from this website: http://www.movable-type.co.uk/scripts/latlong.html Can someone please help me with this? I've try adding, subtracting… the azimuth.. I've tried with the others.. seriously at this point I'm just demoralized.. Thank you in advance -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en Pedro Teixeira www.pedroteixeira.org -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
Re: [android-developers] Please help me with calculating direction from point A to B
Pedro, If I understand you correctly, you are having difficulties with the device's orientation. The bearing angle seems to be computed in the horizontal plane. If you wish to adjust for the device's orientation, you need to concatenate it with the bearing angle. Google for quaternions. This is a (relatively) simple math technique to work with rotations the same way you can work with vectors: add / subtract, interpolate. -- Kostya 18.09.2010 0:56, Pedro Teixeira пишет: Hi everyone... I'm back with the same issue for the last couple of days… I'm trying to create a compass for my application BUT the difference is that, instead of having a line always pointing to north, I want this line to point for a specific point. I've been trying dozens of algorithms and nothing works.. I've finally found one that points me exactlly to the point I want.. BUT it doesn't move if I change the position of the device which is my objective.. basicly, what I want is that no matter the direction I'm using my device.. the line always point me to the point (picLatitude,picLongitude)… I understood that for the line to move, I can't use static variables… I need to use the values offered by the onSensorChanged(SensorEvent event). This are the data I have available: event.values[0]: azimuth, rotation around the Z axis (device in relation to north, 0º) event.values[1]: pitch, rotation around the X axis event.values[2]: roll, rotation around the Y axis mLatitude: device current latitude gottern from GPS (variable) mLongitude: device current longitude gotten from GPS (variable) picLatitude: static picture latitude established previously picLongitude: static picture longitude established previously distance: distance in Km from device to the picture calculated previously And this the formula that works correct, and gives me the correct angle.. ( BUT IT DOESN'T USE ANY OF THE SENSOR DATA SO THE LINE COMPASS DOESNT MOVE): double dLong = picLongitude - mLongitude; double y = (Math.sin(dLong) * Math.cos(picLatitude)); double x = (Math.cos(mLatitude) * Math.sin(picLatitude) - Math.sin(mLatitude)*Math.cos(picLatitude)*Math.cos(dLong)); double angleDegreesWrongRange = Math.abs(Math.toDegrees(Math.atan2(y, x))); float angleDegrees = (float) ((angleDegreesWrongRange+360) % 360); myCompass.updateDirection(angleDegrees); I got this bearing formula from this website: http://www.movable-type.co.uk/scripts/latlong.html Can someone please help me with this? I've try adding, subtracting… the azimuth.. I've tried with the others.. seriously at this point I'm just demoralized.. Thank you in advance -- Kostya Vasilyev -- WiFi Manager + pretty widget -- http://kmansoft.wordpress.com -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
[android-developers] Please help me with calculating direction from point A to B
Hi everyone... I'm back with the same issue for the last couple of days… I'm trying to create a compass for my application BUT the difference is that, instead of having a line always pointing to north, I want this line to point for a specific point. I've been trying dozens of algorithms and nothing works.. I've finally found one that points me exactlly to the point I want.. BUT it doesn't move if I change the position of the device which is my objective.. basicly, what I want is that no matter the direction I'm using my device.. the line always point me to the point (picLatitude,picLongitude)… I understood that for the line to move, I can't use static variables… I need to use the values offered by the onSensorChanged(SensorEvent event). This are the data I have available: event.values[0]: azimuth, rotation around the Z axis (device in relation to north, 0º) event.values[1]: pitch, rotation around the X axis event.values[2]: roll, rotation around the Y axis mLatitude: device current latitude gottern from GPS (variable) mLongitude: device current longitude gotten from GPS (variable) picLatitude: static picture latitude established previously picLongitude: static picture longitude established previously distance: distance in Km from device to the picture calculated previously And this the formula that works correct, and gives me the correct angle.. ( BUT IT DOESN'T USE ANY OF THE SENSOR DATA SO THE LINE COMPASS DOESNT MOVE): double dLong = picLongitude - mLongitude; double y = (Math.sin(dLong) * Math.cos(picLatitude)); double x = (Math.cos(mLatitude) * Math.sin(picLatitude) - Math.sin(mLatitude)*Math.cos(picLatitude)*Math.cos(dLong)); double angleDegreesWrongRange = Math.abs(Math.toDegrees(Math.atan2(y, x))); float angleDegrees = (float) ((angleDegreesWrongRange+360) % 360); myCompass.updateDirection(angleDegrees); I got this bearing formula from this website: http://www.movable-type.co.uk/scripts/latlong.html Can someone please help me with this? I've try adding, subtracting… the azimuth.. I've tried with the others.. seriously at this point I'm just demoralized.. Thank you in advance -- You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
