Add FormFactorBAPol for polarized SANS

Core/Basics/BornAgainNamespace.h

@@ -123,6 +123,7 @@ const std::string FormFactorSphereLogNormalRadiusType = "FormFactorSphereLogNorm
 const std::string FormFactorSphereUniformRadiusType = "FormFactorSphereUniformRadius";
 const std::string FormFactorDWBAType = "FormFactorDWBA";
 const std::string FormFactorPolarizedDWBAType = "FormFactorDWBAPol";
+const std::string FormFactorPolarizedBAType = "FormFactorBAPol";
 
 const std::string FormFactorCoreShellType = "FormFactorCoreShell";
 const std::string FormFactorDecoratorPositionFactorType = "FormFactorDecoratorPositionFactor";

Core/Multilayer/FormFactorBAPol.cpp

+// ************************************************************************** //
+//
+//  BornAgain: simulate and fit scattering at grazing incidence
+//
+//! @file      Core/Multilayer/FormFactorBAPol.cpp
+//! @brief     Defines class FormFactorBAPol.
+//!
+//! @homepage  http://www.bornagainproject.org
+//! @license   GNU General Public License v3 or higher (see COPYING)
+//! @copyright Forschungszentrum Jülich GmbH 2018
+//! @authors   Scientific Computing Group at MLZ (see CITATION, AUTHORS)
+//
+// ************************************************************************** //
+
+#include "FormFactorBAPol.h"
+#include "BornAgainNamespace.h"
+#include "WavevectorInfo.h"
+#include <stdexcept>
+
+
+FormFactorBAPol::FormFactorBAPol(const IFormFactor& form_factor)
+    : mP_form_factor(form_factor.clone())
+{
+    setName(BornAgain::FormFactorPolarizedBAType);
+}
+
+FormFactorBAPol::~FormFactorBAPol() =default;
+
+FormFactorBAPol* FormFactorBAPol::clone() const
+{
+    return new FormFactorBAPol(*mP_form_factor);
+}
+
+complex_t FormFactorBAPol::evaluate(const WavevectorInfo&) const
+{
+    throw std::runtime_error("FormFactorBAPol::evaluate: "
+                             "should never be called for matrix interactions");
+}
+
+Eigen::Matrix2cd FormFactorBAPol::evaluatePol(const WavevectorInfo& wavevectors) const
+{
+    Eigen::Matrix2cd ff_BA = mP_form_factor->evaluatePol(wavevectors);
+    Eigen::Matrix2cd result;
+    result(0,0) = -ff_BA(1,0);
+    result(0,1) = ff_BA(0,0);
+    result(1,0) = -ff_BA(1,1);
+    result(1,1) = ff_BA(0,1);
+    return result;
+}
+
+double FormFactorBAPol::bottomZ(const IRotation& rotation) const
+{
+    return mP_form_factor->bottomZ(rotation);
+}
+
+double FormFactorBAPol::topZ(const IRotation& rotation) const
+{
+    return mP_form_factor->topZ(rotation);
+}

Core/Multilayer/FormFactorBAPol.h

+// ************************************************************************** //
+//
+//  BornAgain: simulate and fit scattering at grazing incidence
+//
+//! @file      Core/Multilayer/FormFactorBAPol.h
+//! @brief     Defines class FormFactorBAPol.
+//!
+//! @homepage  http://www.bornagainproject.org
+//! @license   GNU General Public License v3 or higher (see COPYING)
+//! @copyright Forschungszentrum Jülich GmbH 2018
+//! @authors   Scientific Computing Group at MLZ (see CITATION, AUTHORS)
+//
+// ************************************************************************** //
+
+#ifndef FORMFACTORBAPOL_H
+#define FORMFACTORBAPOL_H
+
+#include "IFormFactor.h"
+#include <memory>
+
+//! Evaluates the matrix BA term in a polarized IFormFactor.
+
+//! @ingroup formfactors_internal
+
+class FormFactorBAPol final : public IFormFactor
+{
+public:
+    FormFactorBAPol(const IFormFactor& form_factor);
+    ~FormFactorBAPol() override;
+
+    FormFactorBAPol* clone() const override;
+
+    void accept(INodeVisitor* visitor) const override { visitor->visit(this); }
+
+    void setAmbientMaterial(Material material) override {
+        mP_form_factor->setAmbientMaterial(std::move(material));
+    }
+
+    //! Throws not-implemented exception
+    complex_t evaluate(const WavevectorInfo& wavevectors) const override;
+
+    //! Calculates and returns a polarized form factor calculation in BA
+    Eigen::Matrix2cd evaluatePol(const WavevectorInfo& wavevectors) const override;
+
+    double volume() const override { return mP_form_factor->volume(); }
+
+    double radialExtension() const override { return mP_form_factor->radialExtension(); }
+
+    double bottomZ(const IRotation& rotation) const override;
+
+    double topZ(const IRotation& rotation) const override;
+
+private:
+    //! The form factor for BA
+    std::unique_ptr<IFormFactor> mP_form_factor;
+};
+
+#endif // FORMFACTORBAPOL_H