Mercurial > dive4elements > river
comparison flys-artifacts/src/main/java/de/intevation/flys/artifacts/math/BackJumpCorrector.java @ 406:663aa18bee7f
Back jump correction should work now for both flow directions.
flys-artifacts/trunk@1848 c6561f87-3c4e-4783-a992-168aeb5c3f6f
| author | Sascha L. Teichmann <sascha.teichmann@intevation.de> |
|---|---|
| date | Sat, 07 May 2011 21:34:02 +0000 |
| parents | f165c7d5d6db |
| children | 2dbbb5be30a1 |
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| 405:55c2b0d9999e | 406:663aa18bee7f |
|---|---|
| 36 | 36 |
| 37 public double [] getCorrected() { | 37 public double [] getCorrected() { |
| 38 return corrected; | 38 return corrected; |
| 39 } | 39 } |
| 40 | 40 |
| 41 private static final boolean isIncreasing(double [] ws) { | |
| 42 int inc = 0; | |
| 43 int dec = 0; | |
| 44 int sweet = (ws.length-1)/2; | |
| 45 for (int i = 1; i < ws.length; ++i) { | |
| 46 if (ws[i] > ws[i-1]) { | |
| 47 if (++inc > sweet) { | |
| 48 return true; | |
| 49 } | |
| 50 } | |
| 51 else if (++dec > sweet) { | |
| 52 return false; | |
| 53 } | |
| 54 } | |
| 55 return inc > sweet; | |
| 56 } | |
| 57 | |
| 41 public boolean doCorrection(double [] km, double [] ws) { | 58 public boolean doCorrection(double [] km, double [] ws) { |
| 59 boolean isIncreasing = isIncreasing(ws); | |
| 60 | |
| 61 if (isIncreasing) { | |
| 62 // mirror along x axis to simulate decreasing values | |
| 63 ws = (double [])ws.clone(); | |
| 64 for (int i = 0; i < ws.length; ++i) { | |
| 65 ws[i] = -ws[i]; | |
| 66 } | |
| 67 } | |
| 68 | |
| 69 boolean hasBackJumps = doCorrectionClean(km, ws); | |
| 70 | |
| 71 if (hasBackJumps && isIncreasing) { | |
| 72 // mirror back | |
| 73 for (int i = 0; i < corrected.length; ++i) { | |
| 74 corrected[i] = -corrected[i]; | |
| 75 } | |
| 76 } | |
| 77 | |
| 78 return hasBackJumps; | |
| 79 } | |
| 80 | |
| 81 protected boolean doCorrectionClean(double [] km, double [] ws) { | |
| 42 int N = km.length; | 82 int N = km.length; |
| 43 | 83 |
| 44 if (N != ws.length) { | 84 if (N != ws.length) { |
| 45 throw new IllegalArgumentException("km.length != ws.length"); | 85 throw new IllegalArgumentException("km.length != ws.length"); |
| 46 } | 86 } |