1 files changed, 87 insertions, 0 deletions
diff --git a/utils/mathvec.h b/utils/mathvec.h
new file mode 100644
index 00000000..f8c60e5d
--- /dev/null
+++ b/utils/mathvec.h
@@ -0,0 +1,87 @@
+#ifndef _MATH_VECTOR_H_
+#define _MATH_VECTOR_H_
+
+#include <vector>
+#include <iostream>
+#include <cassert>
+
+class Vec {
+ private:
+  std::vector<double> _v;
+
+ public:
+  Vec(const size_t n = 0, const double val = 0) { _v.resize(n, val); }
+  Vec(const std::vector<double>& v) : _v(v) {}
+  const std::vector<double>& STLVec() const { return _v; }
+  std::vector<double>& STLVec() { return _v; }
+  size_t Size() const { return _v.size(); }
+  double& operator[](int i) { return _v[i]; }
+  const double& operator[](int i) const { return _v[i]; }
+  Vec& operator+=(const Vec& b) {
+    assert(b.Size() == _v.size());
+    for (size_t i = 0; i < _v.size(); i++) {
+      _v[i] += b[i];
+    }
+    return *this;
+  }
+  Vec& operator*=(const double c) {
+    for (size_t i = 0; i < _v.size(); i++) {
+      _v[i] *= c;
+    }
+    return *this;
+  }
+  void Project(const Vec& y) {
+    for (size_t i = 0; i < _v.size(); i++) {
+      //      if (sign(_v[i]) != sign(y[i])) _v[i] = 0;
+      if (_v[i] * y[i] <= 0) _v[i] = 0;
+    }
+  }
+};
+
+inline double dot_product(const Vec& a, const Vec& b) {
+  double sum = 0;
+  for (size_t i = 0; i < a.Size(); i++) {
+    sum += a[i] * b[i];
+  }
+  return sum;
+}
+
+inline std::ostream& operator<<(std::ostream& s, const Vec& a) {
+  s << "(";
+  for (size_t i = 0; i < a.Size(); i++) {
+    if (i != 0) s << ", ";
+    s << a[i];
+  }
+  s << ")";
+  return s;
+}
+
+inline const Vec operator+(const Vec& a, const Vec& b) {
+  Vec v(a.Size());
+  assert(a.Size() == b.Size());
+  for (size_t i = 0; i < a.Size(); i++) {
+    v[i] = a[i] + b[i];
+  }
+  return v;
+}
+
+inline const Vec operator-(const Vec& a, const Vec& b) {
+  Vec v(a.Size());
+  assert(a.Size() == b.Size());
+  for (size_t i = 0; i < a.Size(); i++) {
+    v[i] = a[i] - b[i];
+  }
+  return v;
+}
+
+inline const Vec operator*(const Vec& a, const double c) {
+  Vec v(a.Size());
+  for (size_t i = 0; i < a.Size(); i++) {
+    v[i] = a[i] * c;
+  }
+  return v;
+}
+
+inline const Vec operator*(const double c, const Vec& a) { return a * c; }
+
+#endif