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Search found 10 results on 1 pages for 'azimuth'.

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  • Need to calculate rotation-vector from Sensor.TYPE_ORIENTATION data

    - by Sponge
    I need to calculate a rotation vector out of the data i get from Sensor.TYPE_ORIENTATION. The sensor data is defined like this: the values have to be recalculated to become a correct 3d position: values[0]: Azimuth, angle between the magnetic north direction and the Y axis, around the Z axis (0 to 359). 0=North, 90=East, 180=South, 270=West values[1]: Pitch, rotation around X axis (-180 to 180), with positive values when the z-axis moves toward the y-axis. values[2]: Roll, rotation around Y axis (-90 to 90), with positive values when the x-axis moves away from the z-axis I need all three values like the Z axis value (from 0 to 360 degree). I tried a lot but cant figure out how to do this :/ i also tried to use Sensor.TYPE_ACCELEROMETER and Sensor.TYPE_MAGNETIC_FIELD to calculate this 3d vector on my own. here is the code: final float[] inR = new float[16]; // load inR matrix from current sensor data: SensorManager.getRotationMatrix(inR, null, gravityValues, geomagneticValues); float[] orientation = new float[3]; SensorManager.getOrientation(inR, orientation); mapMagAndAcclDataToVector(orientation); //here i do some *360 stuff orientetionChanged(orientation); //then the correct values are passed (in theorie) But this didn't work and i think it is much to complicated. So i bet there is a simple solution how to recalc the values of ensor.TYPE_ORIENTATION to make them a 3d rotation vector, but i just dont know how to do it. If you know the answer please tell me.

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  • Programmatically creating vector arrows in KML

    - by mettadore
    Does anyone have any practical examples of programmatically drawing icons as vectors in KML? Specifically, I have data with a magnitude and an azimuth at given coordinates, and I would like to have icons (or another graphical element) generated based on these values. Some thoughts on how I might approach it: Image directory (a brute force way): Make an image director of 360 different image files (probably batch rotate a single image) each pointing in a cooresponding azimuth. I've seen things like "Excel to KML," but am looking for code that I can use within a program, rather than a web utility. Issue: Arrow does not contain magnitude context, so that would have to be a label. I'd rather dynamically lengthen the arrow. Line creation in KML: Perhaps create a formula that creates a line with the origin at the coordinate points, with the length of the line proportional to the magnitute, and angled according to azimuth. There would then be two more lines, perhaps 30 degrees or so extending from the end of the previous line to make the arrow head. Issues: Not a separate image icon, so not sure how it would work in KML. Also not sure how easy it would be to generate this algorithm. Separate image generation: Perhaps create a PHP file that uses imagemagick or something similar to dynamically generate a .png file in a similar method to the above, and then link to the icon using the URI "domain.tld/imagegen.php?magnitude=magvalue&azimuth=azmvalue". Issue: Still have the problem of actually writing the algorithm for image generation. So, the question: has anyone else come up with solutions for programmatic vector (rather than merely arrow) generation?

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  • && (AND) and || (OR) in Java IF statements

    - by Azimuth
    My question might be very basic but still I think it worths to ask. I have the following code: if(!partialHits.get(req_nr).containsKey(z) || partialHits.get(req_nr).get(z) < tmpmap.get(z)){ partialHits.get(z).put(z, tmpmap.get(z)); } where partialHits is a HashMap. What will happen if the first statement is true? Will Java still check the second statement? Because in order the first statement to be true, the HashMap should not contain the given key, so if the second statement is checked, I will get NullPointerException. So in simple words, if we have the following code if(a && b) if(a || b) would Java check b if a is false in the first case and if a is true in the second case?

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  • Using machine learning to aim mirrors in a solar array?

    - by Buttons840
    I've been thinking about solar collectors where several independent mirrors to focus the light on a solar collector, similar to the following design from Energy Innovations. Because there will be flaws in the assembly of this solar array, I am proceeding with the following assumptions (or lack thereof): The software knows the "position" of each mirror, but doesn't know how this position relates to the real world or to other mirrors. This will account for poor mirror calibration or other environmental factors which may effect one mirror but not the others. If a mirror moves 10 units in one direction, and then 10 units in the opposite direction, it will end up where it originally started. I would like to use machine learning to position the mirrors correctly and focus the light on the collector. I expect I would approach this as an optimization problem, optimizing the mirror positions to maximize the heat inside the collector and the power output. The problem is finding a small target in a noisy high-dimensional space (considering each mirror has 2 axis of rotation). Some of the problems I anticipate are: cloudy days, even if you stumble upon the perfect mirror alignment, it might be cloudy at the time noisy sensor data the sun is a moving target, it moves along a path, and follows a different path every day - although you could calculate the exact position of the sun at any time, you wouldn't know how that position relates to your mirrors My question isn't about the solar array, but possible machine learning techniques that would help in this "small target in a noisy high dimensional-space" problem. I mentioned the solar array because it was the catalyst for this question and a good example. What machine learning techniques can find such a small target in a noisy high-dimensional space? EDIT: A few additional thoughts: Yes, you can calculate the suns position in the real world, but you don't know how the mirrors position is related to the real world (unless you've learned it somehow). You might know the suns azimuth is 220 degrees, and the suns elevation is 60 degrees, and you might know a mirror is at position (-20, 42); now tell me, is that mirror correctly aligned with the sun? You don't know. Lets assume you have some very sophisticated heat measurements, and you know "with this heat level, there must be 2 mirrors correctly aligned". Now the question is, which two mirrors (out of 25 or more) are correctly aligned? One solution I considered was to approximate the correct "alignment function" using a neural network which would take the suns azimuth and elevation as input and output a large array with 2 values for each mirror which correspond to the 2 axis of each mirror. I'm not sure what the best training method is though.

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  • Using getRotationMatrix and getOrientation in Android 2.1

    - by aaronmar
    I've been having issues with this for far too long. This code should output dx,dy,dz for the accelerometer, and a running total of the dx. It should also output azimuth, pitch, and roll. I've used info from http://bit.ly/codeUsed, but to no avail. This code does not correctly output pitch, azimuth, or roll. It outputs 0.0, -0.0, -0.0 for the last three textviews, respectively. Please restore my sanity by helping me switch (event.sensor.getType()) { case Sensor.TYPE_ACCELEROMETER: accelerometerValues = event.values.clone(); case Sensor.TYPE_MAGNETIC_FIELD: geomagneticMatrix = event.values.clone(); sensorReady = true; break; default: break; } if (geomagneticMatrix != null && accelerometerValues != null && sensorReady) { sensorReady = false; float[] R = new float[16]; float[] I = new float[16]; SensorManager.getRotationMatrix(R, I, accelerometerValues, geomagneticMatrix); float[] actual_orientation = new float[3]; SensorManager.getOrientation(R, actual_orientation); tvXCoordinate.setText(accelerometerValues[0] + ""); tvYCoordinate.setText(accelerometerValues[1] + ""); tvZCoordinate.setText(accelerometerValues[2] + ""); floatXTotal += accelerometerValues[0]; tvXTotal.setText(floatXTotal + ""); tvAzimuth.setText(actual_orientation[0] + ""); tvPitch.setText(actual_orientation[1] + ""); tvRoll.setText(actual_orientation[2] + ""); }

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  • Great Circle & Ray intersection

    - by Karl T
    I have a Latitude, Longitude, and a direction of travel in degrees true north. I would like to calculate if I will intersect a line defined by two more Lat/Lon points. I figure the two points defining the line would create my great circle and my location and azimuth would define my ray (or possibly a small circle). Any ideas?

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  • Great Circle & Rhumb line intersection

    - by Karl T
    I have a Latitude, Longitude, and a direction of travel in degrees true north. I would like to calculate if I will intersect a line defined by two more Lat/Lon points. I figure the two points defining the line would create my great circle and my location and azimuth would define my Rhumb line. I am only interested in intersections that will occur with a few hundred kilometers so I do not need every possible solution. I have no idea where to begin.

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  • change view with onSensorChanged result

    - by tipu
    I have a view, set by setContentView(new CompassView(this)); I have the onDraw and update methods filled out. What I need to do with the view CompassView is update my view with the new data at the end of the call in the onSensorChanged method. The methods I have to fill out, I believe, are the surfaceChanged and surfaceCreated. They are normally using threads which takes care of the update and onDraw calls but I removed the thread because when the thread was enabled, in the infinite while loop I was never getting any azimuth value what so ever.

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  • Accelerometer gravity components

    - by Dvd
    Hi, I know this question is definitely solved somewhere many times already, please enlighten me if you know of their existence, thanks. Quick rundown: I want to compute from a 3 axis accelerometer the gravity component on each of these 3 axes. I have used 2 axes free body diagrams to work out the accelerometer's gravity component in the world X-Z, Y-Z and X-Y axes. But the solution seems slightly off, it's acceptable for extreme cases when only 1 accelerometer axis is exposed to gravity, but for a pitch and roll of both 45 degrees, the combined total magnitude is greater than gravity (obtained by Xa^2+Ya^2+Za^2=g^2; Xa, Ya and Za are accelerometer readings in its X, Y and Z axis). More detail: The device is a Nexus One, and have a magnetic field sensor for azimuth, pitch and roll in addition to the 3-axis accelerometer. In the world's axis (with Z in the same direction as gravity, and either X or Y points to the north pole, don't think this matters much?), I assumed my device has a pitch (P) on the Y-Z axis, and a roll (R) on the X-Z axis. With that I used simple trig to get: Sin(R)=Ax/Gxz Cos(R)=Az/Gxz Tan(R)=Ax/Az There is another set for pitch, P. Now I defined gravity to have 3 components in the world's axis, a Gxz that is measurable only in the X-Z axis, a Gyz for Y-Z, and a Gxy for X-Y axis. Gxz^2+Gyz^2+Gxy^2=2*G^2 the 2G is because gravity is effectively included twice in this definition. Oh and the X-Y axis produce something more exotic... I'll explain if required later. From these equations I obtained a formula for Az, and removed the tan operations because I don't know how to handle tan90 calculations (it's infinity?). So my question is, anyone know whether I did this right/wrong or able to point me to the right direction? Thanks! Dvd

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