Add methods to axis classes to find the index of a given value.

Refs #9319
mantidproject · Apr 23, 2014 · 7f8d0a0 · 7f8d0a0
1 parent 140790b
commit 7f8d0a0
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Showing 11 changed files with 114 additions and 2 deletions.
diff --git a/Code/Mantid/Framework/API/inc/MantidAPI/Axis.h b/Code/Mantid/Framework/API/inc/MantidAPI/Axis.h
@@ -83,6 +83,9 @@ class MANTID_API_DLL Axis
   /// @param index :: The index
   /// @param value :: The new value
   virtual void setValue(const std::size_t& index, const double& value) = 0;
+  /// Find the index of the given double value
+  virtual size_t indexOfValue(const double value) const = 0;
+
   /// Get the spectrum index
   virtual specid_t spectraNo(const std::size_t& index) const;
 

diff --git a/Code/Mantid/Framework/API/inc/MantidAPI/NumericAxis.h b/Code/Mantid/Framework/API/inc/MantidAPI/NumericAxis.h
@@ -59,6 +59,7 @@ class MANTID_API_DLL NumericAxis: public Axis
   virtual double operator()(const std::size_t& index, const std::size_t& verticalIndex = 0) const;
   /// Set the value at a specific index
   virtual void setValue(const std::size_t& index, const double& value);
+  size_t indexOfValue(const double value) const;
   virtual bool operator==(const Axis&) const;
   std::string label(const std::size_t& index)const;
   /// Create bin boundaries from the point values

diff --git a/Code/Mantid/Framework/API/inc/MantidAPI/SpectraAxis.h b/Code/Mantid/Framework/API/inc/MantidAPI/SpectraAxis.h
@@ -57,6 +57,7 @@ class MANTID_API_DLL SpectraAxis: public Axis
   virtual bool isSpectra() const{return true;}
   virtual double operator()(const std::size_t& index, const std::size_t& verticalIndex = 0) const;
   virtual void setValue(const std::size_t& index, const double& value);
+  size_t indexOfValue(const double value) const;
   virtual bool operator==(const Axis&) const;
   std::string label(const std::size_t& index)const;
 

diff --git a/Code/Mantid/Framework/API/inc/MantidAPI/TextAxis.h b/Code/Mantid/Framework/API/inc/MantidAPI/TextAxis.h
@@ -64,6 +64,8 @@ class MANTID_API_DLL TextAxis: public Axis
   virtual double operator()(const std::size_t& index, const std::size_t& verticalIndex = 0) const;
   /// Set the value at the specified index
   virtual void setValue(const std::size_t& index, const double& value);
+  size_t indexOfValue(const double value) const;
+
   virtual bool operator==(const Axis&) const;
   /// Get the label at the specified index
   std::string label(const std::size_t& index)const;

diff --git a/Code/Mantid/Framework/API/src/Axis.cpp b/Code/Mantid/Framework/API/src/Axis.cpp
@@ -88,7 +88,7 @@ double Axis::getValue(const std::size_t& index, const std::size_t& verticalIndex
 specid_t Axis::spectraNo(const std::size_t& index) const
 {
   UNUSED_ARG(index)
-  throw std::domain_error("Cannot call spectraNo() on a non-spectra axis.");
+      throw std::domain_error("Cannot call spectraNo() on a non-spectra axis.");
 }
 
 } // namespace API

diff --git a/Code/Mantid/Framework/API/src/NumericAxis.cpp b/Code/Mantid/Framework/API/src/NumericAxis.cpp
@@ -71,6 +71,29 @@ void NumericAxis::setValue(const std::size_t& index, const double& value)
   m_values[index] = value;
 }
 
+/**
+ * Finds the closest index of the given value on the axis
+ * @param value A value on the axis
+ * @return The index closest to given value
+ * @throws std::out_of_range if the value is out of range of the axis
+ */
+size_t NumericAxis::indexOfValue(const double value) const
+{
+  const auto & yVals = this->getValues();
+  if(value < yVals.front())
+  {
+    throw std::out_of_range("NumericAxis::indexOfValue() - Input lower than first value.");
+  }
+  auto it = std::lower_bound(yVals.begin(), yVals.end(), value);
+  if (it == yVals.end())
+  {
+    // Out of range
+    throw std::out_of_range("NumericAxis::indexOfValue() - Input value out of range");
+  }
+  // The workspace index is the point in the vector that we found
+  return (it - yVals.begin());
+}
+
 /** Check if two axis defined as spectra or numeric axis are equivalent
  *  @param axis2 :: Reference to the axis to compare to
  *  @return true if self and second axis are equal

diff --git a/Code/Mantid/Framework/API/src/SpectraAxis.cpp b/Code/Mantid/Framework/API/src/SpectraAxis.cpp
@@ -89,6 +89,31 @@ void SpectraAxis::setValue(const std::size_t& index, const double& value)
   const_cast<MatrixWorkspace*>(m_parentWS)->getSpectrum(index)->setSpectrumNo(static_cast<specid_t>(value));
 }
 
+/**
+ * Finds the index of the given value on the axis
+ * @param value A value on the axis. It is treated as a spectrum number and cast to specid_t on input
+ * @return The index closest to given value
+ * @throws std::out_of_range if the value is out of range of the axis
+ */
+size_t SpectraAxis::indexOfValue(const double value) const
+{
+  const specid_t specNo = static_cast<specid_t>(value);
+  // take value as spectrum number
+  for (size_t i = 0; i < this->length(); ++i)
+  {
+    try
+    {
+      if (m_parentWS->getSpectrum(i)->getSpectrumNo() == specNo) return i;
+    }
+    catch(std::range_error& e)
+    {
+      throw std::out_of_range(e.what());
+    }
+  }
+  // Not found if we reached here
+  throw std::out_of_range("SpectraAxis::indexOfValue() - Value not found on axis");
+}
+
 /** Returns the spectrum number at the position given (Spectra axis only)
  *  @param  index The position for which the value is required
  *  @return The spectrum number as an int

diff --git a/Code/Mantid/Framework/API/src/TextAxis.cpp b/Code/Mantid/Framework/API/src/TextAxis.cpp
@@ -63,7 +63,14 @@ void TextAxis::setValue(const std::size_t& index, const double& value)
 {
   UNUSED_ARG(index)
   UNUSED_ARG(value)
-  throw std::domain_error("setValue method cannot be used on a TextAxis.");
+      throw std::domain_error("setValue method cannot be used on a TextAxis.");
+}
+/**
+ * Returns the value that has been passed to it as a size_t
+ */
+size_t TextAxis::indexOfValue(const double value) const
+{
+  return static_cast<size_t>(value);
 }
 
 /** Check if two axis defined as spectra or numeric axis are equivalent

diff --git a/Code/Mantid/Framework/API/test/NumericAxisTest.h b/Code/Mantid/Framework/API/test/NumericAxisTest.h
@@ -159,6 +159,35 @@ class NumericAxisTest : public CxxTest::TestSuite
     }
   }
 
+  void test_indexOfValue_Gives_Correct_Value_When_Input_In_Range()
+  {
+    const size_t npoints(5);
+    NumericAxis axis(npoints);
+    for(size_t i = 0; i < npoints; ++i)
+    {
+      axis.setValue(i, static_cast<double>(i));
+    }
+
+    TS_ASSERT_EQUALS(0, axis.indexOfValue(0.0));
+    TS_ASSERT_EQUALS(4, axis.indexOfValue(4.0));
+    TS_ASSERT_EQUALS(3, axis.indexOfValue(2.5));
+  }
+
+  //-------------------------------- Failure cases ----------------------------
+
+  void test_indexOfValue_Throws_When_Input_Not_In_Axis_Range()
+  {
+    const size_t npoints(5);
+    NumericAxis axis(npoints);
+    for(size_t i = 0; i < npoints; ++i)
+    {
+      axis.setValue(i, static_cast<double>(i));
+    }
+
+    TS_ASSERT_THROWS(axis.indexOfValue(-0.1), std::out_of_range);
+    TS_ASSERT_THROWS(axis.indexOfValue(4.1), std::out_of_range);
+  }
+
 private:
   Axis *numericAxis;
 };

diff --git a/Code/Mantid/Framework/API/test/SpectraAxisTest.h b/Code/Mantid/Framework/API/test/SpectraAxisTest.h
@@ -124,6 +124,21 @@ class SpectraAxisTest : public CxxTest::TestSuite
     }    
   }
 
+  void testIndexOfValue_Treats_Input_As_Spectrum_No()
+  {
+    for (int i=0; i<5; ++i)
+    {
+      TS_ASSERT_EQUALS(i, spectraAxis->indexOfValue(static_cast<double>(2*i)) );
+    }
+  }
+
+  // --------------------------------------- Failure cases --------------------
+  void testIndexOfValue_Throws_out_of_range_error_If_Input_Not_In_Range()
+  {
+    TS_ASSERT_THROWS(spectraAxis->indexOfValue(20.), std::out_of_range);
+  }
+
+
 private:
   WorkspaceTester *ws;
   Axis *spectraAxis;

diff --git a/Code/Mantid/Framework/API/test/TextAxisTest.h b/Code/Mantid/Framework/API/test/TextAxisTest.h
@@ -137,6 +137,12 @@ class TextAxisTest : public CxxTest::TestSuite
     TS_ASSERT_EQUALS(ta.getMin() + 1, ta.getMax())
   }
 
+  void test_indexOfValue_Returns_Input_As_Index()
+  {
+    TextAxis ta(2);
+    TS_ASSERT_EQUALS(static_cast<size_t>(1.5), ta.indexOfValue(1.5));
+    TS_ASSERT_EQUALS(static_cast<size_t>(-1), ta.indexOfValue(-1.5));
+  }
 
 };