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POGPL-compatible graphing library for Android
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copied!<p>In a similar approach to <a href="https://stackoverflow.com/questions/424752/any-good-graphing-packages-for-android">this question</a>, I am looking for a way to plot data points on to a view in Android. Preferably, a library which will do this for arbitrary-ranged input, as well as allow panning and zooming (via pinch or zoom bar).</p> <p>Right now, I have subclass-ed a view which does the following normalization:</p> <pre><code> final int width = View.MeasureSpec.getSize(this.widthMeasureSpec); final int height = View.MeasureSpec.getSize(this.heightMeasureSpec); final float factorA = width / (maxA - minA); final float factorS = height / (maxS - minS); final float constFactorA = factorA * minA; final float constFactorS = factorS * minS; final int dataLength = data.length; for (int i = 0; i < dataLength; ++i) { if (i % 2 == 0) _data[i] = _data[i] * factorA - constFactorA; else _data[i] = _data[i] * factorS - constFactorS; } </code></pre> <p>and a call in onDraw() to the drawPoints method of a canvas (also, I update this.widthMeasureSpec and this.heightMeasureSpec in onMeasure()).</p> <p>This is with minA/maxA as the bounds for my independent variable and minS/maxS as the bounds for my dependent variable.</p> <p>This works fine for displaying the data, but I am hoping someone else has solved the problem of drawing the axes and panning/zooming.</p> <p>I have ~150,000 data points, and I would prefer to keep these as floats to save half the memory. I don't know how big decimal numbers are in JavaScript, but I really don't want to resort to passing data in through JavaScript for the Google Charts API or an HTML-based solution for memory's sake.</p> <p>I'm running this on a MyTouch 3g (the original, before 3.5mm jack and it's RAM upgrade), so performance is an issue. I'd like to release the final project under the GPLv3, so this excludes <a href="http://android.arnodenhond.com/components/graphview" rel="nofollow noreferrer">GraphView</a>.</p> <p>The graphs are of the same type as <a href="https://en.wikipedia.org/wiki/File:LogisticMap_BifurcationDiagram.png" rel="nofollow noreferrer">this</a>, so any optimization by excluding points that are too close together to show up on screen would definitely make a difference.</p>

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