STYLE: Replace NumericTraits<double>::OneValue() calls by 1.0

Aims to improve code readability (assuming that most programmers know
that the type of the floating point literal `1.0` is `double`, according
to the C++ Standard).

Modules/Core/Common/include/itkVersor.hxx

@@ -444,7 +444,7 @@ Versor<T>::Set(const VectorType & axis)
     throw exception;
   }
 
-  const ValueType cosangle2 = std::sqrt(NumericTraits<double>::OneValue() - sinangle2 * sinangle2);
+  const ValueType cosangle2 = std::sqrt(1.0 - sinangle2 * sinangle2);
 
   m_X = axis[0];
   m_Y = axis[1];

Modules/Core/Common/test/itkCompensatedSummationTest2.cxx

@@ -74,7 +74,7 @@ class CompensatedSummationTest2Associate
       itk::CompensatedSummation<double> compensatedSum;
       for (DomainType::IndexValueType i = subdomain[0]; i <= subdomain[1]; ++i)
       {
-        double value = itk::NumericTraits<double>::OneValue() / 7;
+        double value = 1.0 / 7;
         this->m_PerThreadCompensatedSum[threadId].AddElement(value);
       }
     }

Modules/Core/Common/test/itkMathTest.cxx

@@ -622,8 +622,8 @@ main(int, char *[])
     }
 
     // Test comparison values of different types
-    if (itk::Math::NotExactlyEquals(itk::NumericTraits<float>::OneValue(), itk::NumericTraits<double>::OneValue()) ||
-        itk::Math::NotExactlyEquals(itk::NumericTraits<double>::OneValue(), static_cast<float>(1)))
+    if (itk::Math::NotExactlyEquals(itk::NumericTraits<float>::OneValue(), 1.0) ||
+        itk::Math::NotExactlyEquals(1.0, static_cast<float>(1)))
     {
       std::cout << __FILE__ << " " << __LINE__ << " " << f << " == " << d << std::endl;
       testPassStatus = EXIT_FAILURE;
@@ -633,8 +633,8 @@ main(int, char *[])
     FloatRepresentationD oneExact;
     FloatRepresentationD oneAlmost;
 
-    oneExact.asFloat = itk::NumericTraits<double>::OneValue();
-    oneAlmost.asFloat = itk::NumericTraits<double>::OneValue();
+    oneExact.asFloat = 1.0;
+    oneAlmost.asFloat = 1.0;
     oneAlmost.asInt += 1;
 
     // Very close values should be AlmostEqual

Modules/Core/Transform/include/itkCenteredSimilarity2DTransform.hxx

@@ -203,7 +203,7 @@ CenteredSimilarity2DTransform<TParametersValueType>::GetInverse(Self * inverse)
     return false;
   }
   inverse->SetCenter(this->GetCenter()); // inverse have the same center
-  inverse->SetScale(NumericTraits<double>::OneValue() / this->GetScale());
+  inverse->SetScale(1.0 / this->GetScale());
   inverse->SetAngle(-this->GetAngle());
   inverse->SetTranslation(-(this->GetInverseMatrix() * this->GetTranslation()));
   return true;

Modules/Core/Transform/include/itkScaleTransform.hxx

@@ -174,7 +174,7 @@ ScaleTransform<TParametersValueType, NDimensions>::GetInverse(Self * inverse) co
   inverse->SetFixedParameters(this->GetFixedParameters());
   for (unsigned int i = 0; i < SpaceDimension; ++i)
   {
-    inverse->m_Scale[i] = NumericTraits<double>::OneValue() / m_Scale[i];
+    inverse->m_Scale[i] = 1.0 / m_Scale[i];
   }
 
   return true;

Modules/Core/Transform/include/itkSimilarity2DTransform.hxx

@@ -247,7 +247,7 @@ Similarity2DTransform<TParametersValueType>::GetInverse(Self * inverse) const
     return false;
   }
   inverse->SetCenter(this->GetCenter()); // inverse have the same center
-  inverse->SetScale(NumericTraits<double>::OneValue() / this->GetScale());
+  inverse->SetScale(1.0 / this->GetScale());
   inverse->SetAngle(-this->GetAngle());
   inverse->SetTranslation(-(this->GetInverseMatrix() * this->GetTranslation()));
 

Modules/Numerics/Optimizers/src/itkMultipleValuedVnlCostFunctionAdaptor.cxx

@@ -44,7 +44,7 @@ MultipleValuedVnlCostFunctionAdaptor::SetScales(const ScalesType & scales)
       itkGenericExceptionMacro("ERROR: Scales must have value greater than epsilon! Scale[" << i
                                                                                             << "] = " << scales[i]);
     }
-    m_InverseScales[i] = NumericTraits<double>::OneValue() / scales[i];
+    m_InverseScales[i] = 1.0 / scales[i];
   }
   m_ScalesInitialized = true;
 }

Modules/Numerics/Optimizers/src/itkOptimizer.cxx

@@ -45,7 +45,7 @@ Optimizer::SetScales(const ScalesType & scales)
     {
       itkExceptionMacro("ERROR: Scales must have value greater than epsilon! Scale[" << i << "] = " << m_Scales[i]);
     }
-    m_InverseScales[i] = NumericTraits<double>::OneValue() / m_Scales[i];
+    m_InverseScales[i] = 1.0 / m_Scales[i];
   }
   m_ScalesInitialized = true;
   this->Modified();

Modules/Numerics/Optimizers/src/itkSingleValuedVnlCostFunctionAdaptor.cxx

@@ -46,7 +46,7 @@ SingleValuedVnlCostFunctionAdaptor::SetScales(const ScalesType & scales)
       itkGenericExceptionMacro("ERROR: Scales must have value greater than epsilon! Scale[" << i
                                                                                             << "] = " << scales[i]);
     }
-    m_InverseScales[i] = NumericTraits<double>::OneValue() / scales[i];
+    m_InverseScales[i] = 1.0 / scales[i];
   }
   m_ScalesInitialized = true;
 }

Modules/Numerics/Statistics/include/itkHistogram.hxx

@@ -626,13 +626,13 @@ Histogram<TMeasurement, TFrequencyContainer>::Quantile(unsigned int dimension, d
   {
     n = size - 1;
     InstanceIdentifier m = NumericTraits<InstanceIdentifier>::ZeroValue();
-    p_n = NumericTraits<double>::OneValue();
+    p_n = 1.0;
     do
     {
       f_n = this->GetFrequency(n, dimension);
       cumulated += f_n;
       p_n_prev = p_n;
-      p_n = NumericTraits<double>::OneValue() - cumulated / totalFrequency;
+      p_n = 1.0 - cumulated / totalFrequency;
       n--;
       m++;
     } while (m < size && p_n > p);