[807] | 1 | |
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| 2 | Example of Convergence Tester |
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| 3 | |
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| 4 | Koi, Tatsumi |
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| 5 | SLAC / SCCS |
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| 6 | tkoi@slac.stanford.eedu |
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| 7 | |
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| 8 | This example shows how to use convergece tester in Geant4. |
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| 9 | The aim of Convergence Tester |
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| 10 | After a Monte Carlo simulation, we get an answer. However how to estimate quality of the answer. |
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| 11 | What we must remember is |
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| 12 | Large number of history does not valid result of simulation. |
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| 13 | Small Relative Error does not valid result of simulation |
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| 14 | To provide statistical information to assist establishing valid confidence intervals for Monte Carlo results for users. |
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| 15 | |
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| 16 | Geometry and Physics are same to exampleN03. Please see README.N03 |
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| 17 | |
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| 18 | *********************************************************************************************************************** |
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| 19 | Output example |
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| 20 | |
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| 21 | // Part I.A |
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| 22 | // Basic statistics values |
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| 23 | |
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| 24 | EFFICIENCY = 0.99438477 |
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| 25 | MEAN = 78.477718 |
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| 26 | VAR = 225.50178 |
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| 27 | SD = 15.016717 |
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| 28 | R = 0.0029898448 |
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| 29 | SHIFT = -13.902917 |
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| 30 | VOV = 0.0019924127 |
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| 31 | FOM = 909.19362 |
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| 32 | |
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| 33 | // Part I.B |
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| 34 | // If the largeset scored events happen at next to the last event, |
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| 35 | // then how much the event effects the statistics values of the calculation |
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| 36 | |
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| 37 | THE LARGEST SCORE = 117.3797 and it happend at 510th event |
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| 38 | Affected Mean = 78.487213 and its ratio to orignal is 1.000121 |
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| 39 | Affected VAR = 225.81611 and its ratio to orignal is 1.0013939 |
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| 40 | Affected R = 0.0029912008 and its ratio to orignal is 1.0004535 |
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| 41 | Affected SHIFT = -13.862598 and its ratio to orignal is 0.99709995 |
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| 42 | Affected FOM = 908.89814 and its ratio to orignal is 0.99967501 |
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| 43 | |
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| 44 | // Part I.C |
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| 45 | // Convergence tests results |
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| 46 | |
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| 47 | MEAN distribution is not RANDOM |
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| 48 | r follows 1/sqrt(N) |
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| 49 | r is monotonically decrease 1 |
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| 50 | r is less than 0.1. r = 0.0029898448 |
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| 51 | VOV follows 1/sqrt(N) |
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| 52 | VOV is monotonically decrease 1 |
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| 53 | FOM distribution is RANDOM |
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| 54 | SLOPE is large enough |
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| 55 | This result passes 7 / 8 Convergence Test. |
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| 56 | |
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| 57 | // Part II |
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| 58 | // Profile of statistics values in the history |
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| 59 | |
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| 60 | i/16 till_ith mean var sd r vov fom shift e r2eff r2int |
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| 61 | 1 255 76.935633 252.45045 15.888689 0.012907453 0.038596366 787.70557 -17.661167 0.984375 6.2003968e-05 0.00010394759 |
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| 62 | 2 511 77.389232 257.4632 16.04566 0.0091630923 0.017298474 773.88648 -16.441348 0.98632812 2.707302e-05 5.6725251e-05 |
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| 63 | 3 767 77.665817 248.62651 15.767895 0.0073259372 0.012144321 826.64625 -16.585523 0.98828125 1.5439723e-05 3.8159751e-05 |
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| 64 | 4 1023 77.969112 245.54395 15.669842 0.0062804686 0.0086792682 841.98653 -16.027547 0.99023438 9.6307939e-06 2.9774973e-05 |
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| 65 | 5 1279 78.061919 228.9236 15.130221 0.0054175269 0.0067481801 897.34046 -14.687306 0.9921875 6.1515748e-06 2.3175093e-05 |
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| 66 | 6 1535 77.870133 231.84589 15.226486 0.004989226 0.0054405699 879.44272 -14.43874 0.99283854 4.6960383e-06 2.0180132e-05 |
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| 67 | 7 1791 78.045703 224.72573 14.990855 0.004537414 0.0046643478 908.22153 -14.045519 0.99386161 3.446599e-06 1.7130038e-05 |
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| 68 | 8 2047 78.107287 226.09338 15.036402 0.0042539011 0.0041397452 902.08658 -14.202387 0.99365234 3.1192414e-06 1.4967598e-05 |
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| 69 | 9 2303 78.129941 222.08125 14.902391 0.0039737195 0.0036662056 916.62223 -13.945849 0.99392361 2.6534449e-06 1.3130148e-05 |
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| 70 | 10 2559 78.225505 223.59764 14.953181 0.0037780287 0.0032772248 910.22344 -13.934949 0.99414062 2.3023084e-06 1.1965617e-05 |
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| 71 | 11 2815 78.250797 222.51845 14.917052 0.003592344 0.0029353727 915.19704 -13.768958 0.99431818 2.0292208e-06 1.0871132e-05 |
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| 72 | 12 3071 78.377339 220.83103 14.860385 0.0034208098 0.002628038 928.36413 -13.3624 0.99479167 1.7042976e-06 9.9938329e-06 |
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| 73 | 13 3327 78.364284 221.49591 14.882739 0.0032921001 0.0024634602 923.51719 -13.660307 0.99489183 1.5427886e-06 9.2918778e-06 |
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| 74 | 14 3583 78.464175 220.63749 14.853871 0.0031621629 0.0022668889 928.57248 -13.539324 0.99497768 1.4083908e-06 8.5880937e-06 |
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| 75 | 15 3839 78.420541 224.71581 14.990524 0.0030847599 0.002080651 911.9934 -13.68267 0.99479167 1.363438e-06 8.1498278e-06 |
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| 76 | 16 4095 78.477718 225.50178 15.016717 0.0029898448 0.0019924127 909.4893 -13.902917 0.99438477 1.3786483e-06 7.5583414e-06 |
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| 77 | |
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| 78 | |
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| 79 | ************************************************************************************************************************** |
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| 80 | |
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| 81 | Reference of this Convergence tests |
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| 82 | MCNP(TM) -A General Monte Carlo N-Particle Transport Code |
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| 83 | Version 4B |
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| 84 | Judith F. Briesmeister, Editor |
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| 85 | LA-12625-M, Issued: March 1997, UC 705 and UC 700 |
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| 86 | CHAPTER 2. GEOMETRY, DATA, PHYSICS, AND MATHEMATICS |
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| 87 | VI. ESTIMATION OF THE MONTE CARLO PRECISION |
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| 88 | |
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