Last change
on this file was
7811,
checked in by westram, 13 years ago
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merge from dev [7748] [7749] [7750]
- comments (C→C++ style)
- fixed umlauts in TREEGEN
|
-
Property svn:eol-style set to
native
-
Property svn:keywords set to
Author Date Id Revision
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File size:
1.1 KB
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1 | #include "frand.h" |
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2 | #include <math.h> |
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3 | #include <stdlib.h> |
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4 | |
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5 | static double randval() |
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6 | { |
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7 | // Liefert einen Zufallswert zwischen -0.5 und +0.5 |
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8 | double val = rand(); |
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9 | |
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10 | val /= RAND_MAX; |
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11 | val -= 0.5; |
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12 | |
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13 | assert(val>=-0.5); |
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14 | assert(val <= 0.5); |
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15 | |
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16 | return val; |
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17 | } |
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18 | static double lowfreqrandval(double *val, int teiler) |
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19 | { |
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20 | // Liefert einen niederfrequenten Zufallswert zwischen -0.5 und +0.5 |
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21 | double add = randval()/teiler; |
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22 | |
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23 | *val += add; |
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24 | if (*val<-0.5 || *val>0.5) *val -= 2*add; |
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25 | |
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26 | return *val; |
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27 | } |
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28 | Frand initFrand(double medium, double low, double high) |
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29 | { |
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30 | Frand f = (Frand)malloc(sizeof(*f)); |
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31 | |
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32 | if (!f) outOfMemory(); |
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33 | |
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34 | f->medium = medium; |
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35 | f->alpha = high*2; |
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36 | f->beta = low*2; |
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37 | f->val = randval(); |
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38 | f->teiler = 1; |
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39 | |
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40 | return f; |
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41 | } |
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42 | double getFrand(Frand f) |
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43 | { |
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44 | return f->medium + |
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45 | f->alpha * randval() + |
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46 | f->beta * lowfreqrandval(&(f->val), f->teiler); |
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47 | } |
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48 | void freeFrand(Frand f) |
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49 | { |
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50 | free(f); |
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51 | } |
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52 | double randProb() |
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53 | { |
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54 | // Liefert einen Zufallswert zwischen 0.0 und 1.0 |
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55 | double val = rand(); |
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56 | |
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57 | val /= RAND_MAX; |
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58 | |
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59 | assert(val>=0.0); |
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60 | assert(val<=1.0); |
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61 | |
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62 | return val; |
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63 | } |
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64 | |
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