Including c++ example for the computation of collinear distributions

data/examples/evolution/makeUseOfGPDEvolutionApfel.xml

@@ -37,6 +37,7 @@ calculation of CFFs or observables.
 	    <!-- Select GPD evolution model -->
             <module type="GPDEvolutionModule" name="GPDEvolutionApfel">
 
+	       <!-- Select pQCD order -->
                <param name="qcd_order_type" value="LO" />
 
 	       <!-- Select alpha_s model -->

include/examples.h

@@ -5,6 +5,13 @@
 // GPD EXAMPLES *****************************************
 // ******************************************************
 
+/**
+ * This function demonstrates a simple task as the evaluation of collinear distributions in a single kinematic point.
+ * The result of this function is printed out to the standard output.
+ * These are the values for all defined in the collinear distributions, including singlet and non-singlet combinations for quarks.
+ */
+void computeSingleKinematicsForCollinearDistribution();
+
 /**
  * This function demonstrates a simple task as the evaluation of GPD model in a single kinematic point.
  * The result of this function is printed out to the standard output.

src/examples.cpp

@@ -19,6 +19,7 @@
 #include <partons/beans/observable/ObservableResult.h>
 #include <partons/beans/PerturbativeQCDOrderType.h>
 #include <partons/modules/active_flavors_thresholds/ActiveFlavorsThresholdsConstant.h>
+#include <partons/modules/active_flavors_thresholds/ActiveFlavorsThresholdsQuarkMasses.h>
 #include <partons/modules/convol_coeff_function/ConvolCoeffFunctionModule.h>
 #include <partons/modules/convol_coeff_function/DVCS/DVCSCFFStandard.h>
 #include <partons/modules/convol_coeff_function/DVMP/DVMPCFFGK06.h>
@@ -60,6 +61,27 @@ void computeSingleKinematicsForCollinearDistribution() {
             PARTONS::Partons::getInstance()->getModuleObjectFactory()->newCollinearDistributionModule(
                     PARTONS::CollinearDistributionLHAPDF::classId);
 
+    // Create parameters to configure later GPDEvolutionModule
+    ElemUtils::Parameters parameters;
+
+    parameters.add(
+            ElemUtils::Parameter(
+                    PARTONS::CollinearDistributionType::COLLINEAR_DISTRIBUTION_TYPE_DB_COLUMN_NAME,
+                    PARTONS::CollinearDistributionType::Type::UnpolPDF));
+
+    parameters.add(
+            ElemUtils::Parameter(
+		    PARTONS::CollinearDistributionLHAPDF::PARAM_NAME_SET_NAME,
+                    "CT14nnlo"));
+
+    parameters.add(
+            ElemUtils::Parameter(
+		    PARTONS::CollinearDistributionLHAPDF::PARAM_NAME_SET_MEMBER,
+                    0));
+
+    // Configure collinear-distribution module with previous parameters.
+    pCollinearDistributionModel->configure(parameters);
+
     // Create a CollinearDistributionKinematic(x, MuF2, MuR2) to compute
     PARTONS::CollinearDistributionKinematic colldistKinematic(0.1, 2., 2.);