Re #4158. Changed the least squares.

mantidproject · Apr 2, 2012 · e8c2d03 · e8c2d03
1 parent 4ec88f1
commit e8c2d03
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Showing 2 changed files with 42 additions and 6 deletions.
diff --git a/Code/Mantid/Framework/CurveFitting/src/CostFuncLeastSquares.cpp b/Code/Mantid/Framework/CurveFitting/src/CostFuncLeastSquares.cpp
@@ -17,11 +17,11 @@ double CostFuncLeastSquares::val() const
 {
   checkValidity();
   m_function->function(*m_domain,*m_values);
-  size_t n = nParams();
+  size_t ny = m_values->size();
 
   double retVal = 0.0;
 
-  for (size_t i = 0; i < n; i++)
+  for (size_t i = 0; i < ny; i++)
   {
     double val = ( m_values->getCalculated(i) - m_values->getFitData(i) ) * m_values->getFitWeight(i);
     retVal += val * val;
@@ -85,7 +85,7 @@ double CostFuncLeastSquares::valAndDeriv(std::vector<double>& der) const
       double obs = m_values->getFitData(i);
       double y = ( calc - obs ) * m_values->getFitWeight(i);
       d += y * jacobian.get(i,ip);
-      if (i == 0)
+      if (ip == 0)
       {
         fVal += y * y;
       }

diff --git a/Code/Mantid/Framework/CurveFitting/test/LeastSquaresTest.h b/Code/Mantid/Framework/CurveFitting/test/LeastSquaresTest.h
@@ -78,10 +78,46 @@ class LeastSquaresTest : public CxxTest::TestSuite
     BFGS_Minimizer s;
     s.initialize(costFun);
     TS_ASSERT(s.minimize());
-    TS_ASSERT_DELTA(costFun->val(),0.0,1e-10);
-    TS_ASSERT_DELTA(fun->getParameter("Height"),3.3,1e-10);
-    TS_ASSERT_DELTA(fun->getParameter("Lifetime"),4.4,1e-10);
+    TS_ASSERT_DELTA(costFun->val(),0.0,1e-7);
+    TS_ASSERT_DELTA(fun->getParameter("Height"),9.9,1e-4);
+    TS_ASSERT_DELTA(fun->getParameter("Lifetime"),0.5,1e-4);
     TS_ASSERT_EQUALS(s.getError(),"success");
+
+  }
+
+  void test_val_deriv_valAndDeriv()
+  {
+    const double a = 1.0;
+    const double b = 2.0;
+    std::vector<double> x(3),y(3);
+    x[0] = 0.; y[0] = a * x[0] + b; // == 2.0
+    x[1] = 1.; y[1] = a * x[1] + b; // == 3.0
+    x[2] = 2.; y[2] = a * x[2] + b; // == 4.0
+    API::FunctionDomain1D_sptr domain(new API::FunctionDomain1D(x));
+    API::FunctionValues_sptr values(new API::FunctionValues(*domain));
+    values->setFitData(y);
+    values->setFitWeights(1.0);
+
+    boost::shared_ptr<UserFunction> fun(new UserFunction);
+    fun->setAttributeValue("Formula","a*x+b");
+    fun->setParameter("a",1.1);
+    fun->setParameter("b",2.2);
+
+    boost::shared_ptr<CostFuncLeastSquares> costFun(new CostFuncLeastSquares);
+    costFun->setFittingFunction(fun,domain,values);
+    TS_ASSERT_DELTA(costFun->val(), 0.29, 1e-10); // == 0.2^2 + 0.3^2 + 0.4^2
+
+    std::vector<double> der;
+    costFun->deriv(der);
+    TS_ASSERT_EQUALS(der.size(),2);
+    TS_ASSERT_DELTA(der[0], 2.2, 1e-10); // == 2*(0 * 0.2 + 1 * 0.3 + 2 * 0.4)
+    TS_ASSERT_DELTA(der[1], 1.8, 1e-10); // == 2*(1 * 0.2 + 1 * 0.3 + 1 * 0.4)
+
+    std::vector<double> der1;
+    TS_ASSERT_DELTA(costFun->valAndDeriv(der1),0.29,1e-10);
+    TS_ASSERT_EQUALS(der1.size(),2);
+    TS_ASSERT_DELTA(der1[0], 2.2, 1e-10);
+    TS_ASSERT_DELTA(der1[1], 1.8, 1e-10);
   }
 
 };