diff options
author | bearbin <bearbin@gmail.com> | 2013-07-29 14:55:26 +0200 |
---|---|---|
committer | bearbin <bearbin@gmail.com> | 2013-07-29 14:55:26 +0200 |
commit | fb1044c4e55c726753d094b66756a1cb3bc60ee8 (patch) | |
tree | c61e56725da7dff0154d566722651e2c39c9d6c6 /source/ProbabDistrib.cpp | |
parent | WebAdmin: Removed the duplicate memory usage querying (diff) | |
parent | Changed everyting to Unix line endings. (diff) | |
download | cuberite-fb1044c4e55c726753d094b66756a1cb3bc60ee8.tar cuberite-fb1044c4e55c726753d094b66756a1cb3bc60ee8.tar.gz cuberite-fb1044c4e55c726753d094b66756a1cb3bc60ee8.tar.bz2 cuberite-fb1044c4e55c726753d094b66756a1cb3bc60ee8.tar.lz cuberite-fb1044c4e55c726753d094b66756a1cb3bc60ee8.tar.xz cuberite-fb1044c4e55c726753d094b66756a1cb3bc60ee8.tar.zst cuberite-fb1044c4e55c726753d094b66756a1cb3bc60ee8.zip |
Diffstat (limited to 'source/ProbabDistrib.cpp')
-rw-r--r-- | source/ProbabDistrib.cpp | 284 |
1 files changed, 142 insertions, 142 deletions
diff --git a/source/ProbabDistrib.cpp b/source/ProbabDistrib.cpp index 98c18b8e1..5fa17c276 100644 --- a/source/ProbabDistrib.cpp +++ b/source/ProbabDistrib.cpp @@ -1,142 +1,142 @@ -
-// ProbabDistrib.cpp
-
-// Implements the cProbabDistrib class representing a discrete probability distribution curve and random generator
-
-#include "Globals.h"
-#include "ProbabDistrib.h"
-#include "MersenneTwister.h"
-
-
-
-
-
-
-cProbabDistrib::cProbabDistrib(int a_MaxValue) :
- m_MaxValue(a_MaxValue),
- m_Sum(-1)
-{
-}
-
-
-
-
-
-
-void cProbabDistrib::SetPoints(const cProbabDistrib::cPoints & a_Points)
-{
- ASSERT(!a_Points.empty());
- m_Sum = 0;
- m_Cumulative.clear();
- m_Cumulative.reserve(a_Points.size() + 1);
- int ProbSum = 0;
- int LastProb = 0;
- int LastValue = -1;
- if (a_Points[0].m_Value != 0)
- {
- m_Cumulative.push_back(cPoint(0, 0)); // Always push in the [0, 0] point for easier search algorithm bounds
- LastValue = 0;
- }
- for (cPoints::const_iterator itr = a_Points.begin(), end = a_Points.end(); itr != end; ++itr)
- {
- if (itr->m_Value == LastValue)
- {
- continue;
- }
-
- // Add the current trapezoid to the sum:
- ProbSum += (LastProb + itr->m_Probability) * (itr->m_Value - LastValue) / 2;
- LastProb = itr->m_Probability;
- LastValue = itr->m_Value;
- m_Cumulative.push_back(cPoint(itr->m_Value, ProbSum));
- } // for itr - a_Points[]
- if (LastValue != m_MaxValue)
- {
- m_Cumulative.push_back(cPoint(m_MaxValue, 0)); // Always push in the last point for easier search algorithm bounds
- }
- m_Sum = ProbSum;
-}
-
-
-
-
-
-bool cProbabDistrib::SetDefString(const AString & a_DefString)
-{
- AStringVector Points = StringSplitAndTrim(a_DefString, ";");
- if (Points.empty())
- {
- return false;
- }
- cPoints Pts;
- for (AStringVector::const_iterator itr = Points.begin(), end = Points.end(); itr != end; ++itr)
- {
- AStringVector Split = StringSplitAndTrim(*itr, ",");
- if (Split.size() != 2)
- {
- // Bad format
- return false;
- }
- int Value = atoi(Split[0].c_str());
- int Prob = atoi(Split[1].c_str());
- if (
- ((Value == 0) && (Split[0] != "0")) ||
- ((Prob == 0) && (Split[1] != "0"))
- )
- {
- // Number parse error
- return false;
- }
- Pts.push_back(cPoint(Value, Prob));
- } // for itr - Points[]
-
- SetPoints(Pts);
- return true;
-}
-
-
-
-
-
-int cProbabDistrib::Random(MTRand & a_Rand) const
-{
- int v = a_Rand.randInt(m_Sum);
- return MapValue(v);
-}
-
-
-
-
-
-int cProbabDistrib::MapValue(int a_OrigValue) const
-{
- ASSERT(a_OrigValue >= 0);
- ASSERT(a_OrigValue < m_Sum);
-
- // Binary search through m_Cumulative for placement:
- size_t Lo = 0;
- size_t Hi = m_Cumulative.size() - 1;
- while (Hi - Lo > 1)
- {
- int Mid = (Lo + Hi) / 2;
- int MidProbab = m_Cumulative[Mid].m_Probability;
- if (MidProbab < a_OrigValue)
- {
- Lo = Mid;
- }
- else
- {
- Hi = Mid;
- }
- }
- ASSERT(Hi - Lo == 1);
-
- // Linearly interpolate between Lo and Hi:
- int ProbDif = m_Cumulative[Hi].m_Probability - m_Cumulative[Lo].m_Probability;
- int ValueDif = m_Cumulative[Hi].m_Value - m_Cumulative[Lo].m_Value;
- return m_Cumulative[Lo].m_Value + (a_OrigValue - m_Cumulative[Lo].m_Probability) * ValueDif / ProbDif;
-}
-
-
-
-
+ +// ProbabDistrib.cpp + +// Implements the cProbabDistrib class representing a discrete probability distribution curve and random generator + +#include "Globals.h" +#include "ProbabDistrib.h" +#include "MersenneTwister.h" + + + + + + +cProbabDistrib::cProbabDistrib(int a_MaxValue) : + m_MaxValue(a_MaxValue), + m_Sum(-1) +{ +} + + + + + + +void cProbabDistrib::SetPoints(const cProbabDistrib::cPoints & a_Points) +{ + ASSERT(!a_Points.empty()); + m_Sum = 0; + m_Cumulative.clear(); + m_Cumulative.reserve(a_Points.size() + 1); + int ProbSum = 0; + int LastProb = 0; + int LastValue = -1; + if (a_Points[0].m_Value != 0) + { + m_Cumulative.push_back(cPoint(0, 0)); // Always push in the [0, 0] point for easier search algorithm bounds + LastValue = 0; + } + for (cPoints::const_iterator itr = a_Points.begin(), end = a_Points.end(); itr != end; ++itr) + { + if (itr->m_Value == LastValue) + { + continue; + } + + // Add the current trapezoid to the sum: + ProbSum += (LastProb + itr->m_Probability) * (itr->m_Value - LastValue) / 2; + LastProb = itr->m_Probability; + LastValue = itr->m_Value; + m_Cumulative.push_back(cPoint(itr->m_Value, ProbSum)); + } // for itr - a_Points[] + if (LastValue != m_MaxValue) + { + m_Cumulative.push_back(cPoint(m_MaxValue, 0)); // Always push in the last point for easier search algorithm bounds + } + m_Sum = ProbSum; +} + + + + + +bool cProbabDistrib::SetDefString(const AString & a_DefString) +{ + AStringVector Points = StringSplitAndTrim(a_DefString, ";"); + if (Points.empty()) + { + return false; + } + cPoints Pts; + for (AStringVector::const_iterator itr = Points.begin(), end = Points.end(); itr != end; ++itr) + { + AStringVector Split = StringSplitAndTrim(*itr, ","); + if (Split.size() != 2) + { + // Bad format + return false; + } + int Value = atoi(Split[0].c_str()); + int Prob = atoi(Split[1].c_str()); + if ( + ((Value == 0) && (Split[0] != "0")) || + ((Prob == 0) && (Split[1] != "0")) + ) + { + // Number parse error + return false; + } + Pts.push_back(cPoint(Value, Prob)); + } // for itr - Points[] + + SetPoints(Pts); + return true; +} + + + + + +int cProbabDistrib::Random(MTRand & a_Rand) const +{ + int v = a_Rand.randInt(m_Sum); + return MapValue(v); +} + + + + + +int cProbabDistrib::MapValue(int a_OrigValue) const +{ + ASSERT(a_OrigValue >= 0); + ASSERT(a_OrigValue < m_Sum); + + // Binary search through m_Cumulative for placement: + size_t Lo = 0; + size_t Hi = m_Cumulative.size() - 1; + while (Hi - Lo > 1) + { + int Mid = (Lo + Hi) / 2; + int MidProbab = m_Cumulative[Mid].m_Probability; + if (MidProbab < a_OrigValue) + { + Lo = Mid; + } + else + { + Hi = Mid; + } + } + ASSERT(Hi - Lo == 1); + + // Linearly interpolate between Lo and Hi: + int ProbDif = m_Cumulative[Hi].m_Probability - m_Cumulative[Lo].m_Probability; + int ValueDif = m_Cumulative[Hi].m_Value - m_Cumulative[Lo].m_Value; + return m_Cumulative[Lo].m_Value + (a_OrigValue - m_Cumulative[Lo].m_Probability) * ValueDif / ProbDif; +} + + + + |