1 files changed, 82 insertions, 0 deletions
diff --git a/meowpp/math/utility.h b/meowpp/math/utility.h
new file mode 100644
index 0000000..9bfbb7a
--- /dev/null
+++ b/meowpp/math/utility.h
@@ -0,0 +1,82 @@
+#ifndef   math_utility_H__
+#define   math_utility_H__
+
+#include <cstdlib>
+
+namespace meow{
+  static const double PI = 3.14159265358979323846264338327950288;
+  //#
+  //# === meow:: *Functios* in math/utility.h
+  //#
+  //# [options="header",width="100%",cols="1>s,5<,1<,10<",grid="rows"]
+  //# |==============================================================
+  //# |Name             | Parameters                | Return_Type | Description
+
+  
+  //# |noEPS<T>       |(T `value`, T `eps` = 1e-9) | T |
+  //# 如果abs(輸入的數值) < eps, 則回傳0, 否則回傳輸入的數值
+  template<class T>
+  inline T noEPS(T value, T eps = 1e-9);
+  
+  
+  //# |normalize<T>   |(T `lower`, T `upper`, \ T value)
+  //# | T | `(value - lower) / (upper - lower)`
+  template<class T>
+  inline T normalize(T lower, T upper, T value);
+  
+  
+  //# |denormalize<T> |(T `lower`, T `upper`,
+  //# \ T `ratio`) | T | `lower + (upper - lower) * ratio`
+  template<class T>
+  inline T denormalize(T lower, T upper, T ratio);
+  
+  
+  //# |ratioMapping<T>|(T `l1`, T `u1`,
+  //# \T `m1`, T `l2`,\T `u2`)
+  //# | T | `denormalize(l2, u2, normalize(l1, u1, m1))`
+  template<class T>
+  inline T ratioMapping(T l1, T u1, T m1, T l2, T u2);
+  
+  
+  //# |inRange<T>     |(T const& `mn`, T const& `mx`, \ T const& `v`) | T | 
+  //# `std::max(mn, std::min(mx, v))`
+  template<class T>
+  inline T inRange(T const& mn, T const& mx, T const& v);
+  
+  
+  //# |squ<T>  |(T const& `x`) | T| `x * x`
+  template<class T>
+  inline T squ(T const& x);
+  
+  
+  //# |cub<T>  |(T const& `x`) | T| `x * x * x`
+  template<class T>
+  inline T cub(T const& x);
+
+  //# |average<T>|(T const& `beg`, T const& `end`, \ double `sigs`)| T|
+  //# 只將 `sigs` 個標準差以內的數據拿來取平均
+  template<class T>
+  inline double average(T const& beg, T const& end, double sigs);
+  
+  
+  //# |average<T>|(T const& `beg`, T const& `end`,
+  //# \ T const& `p`, double `sigs`)| T| 同上, 不過這次用 `p` 來加權平均
+  template<class T>
+  inline double average(T const& beg, T const& end, T const& p, double sigs);
+  
+  //# |==============================================================
+  
+  
+  //# 
+  //# [NOTE]
+  //# ====================================
+  //#  * 額外附贈一個 `const double PI = 3.141592653589......`
+  //# ====================================
+  //#
+  //# '''
+  //#
+}
+
+#include "utility.hpp"
+
+#endif // math_utility_H__