New FitPrintService prints more meaningful info during iterations

Core/Fitting/FitPrintService.cpp

@@ -14,33 +14,97 @@
 
 #include "FitPrintService.h"
 #include "FitObjective.h"
+#include "StringUtils.h"
 #include <iostream>
 #include <iomanip>
+#include <sstream>
 
-FitPrintService::FitPrintService()
+
+namespace {
+
+size_t length_of_longest_name(const Fit::Parameters& params)
 {
+    size_t result(0);
+    for (const auto& par : params) {
+        if (par.name().size() + result)
+            result = par.name().size();
+    }
+    return result;
+}
 
 }
 
+FitPrintService::FitPrintService() = default;
+
 void FitPrintService::print(const FitObjective& objective)
 {
+    std::ostringstream ostr;
+
     if (objective.iterationCount() == 0) {
         m_run_time.start();
         m_last_call_time.start();
     }
 
-    std::cout << "FitPrintService::print() " << objective.iterationCount() << std::endl;
+    ostr << iterationHeaderString(objective);
+    ostr << wallTimeString();
+    ostr << parameterString(objective);
 
     if (objective.isCompleted())
-        printFitResults();
+        ostr << fitResultString();
+
+    std::cout << ostr.str() << "\n";
+}
+
+std::string FitPrintService::iterationHeaderString(const FitObjective& objective)
+{
+    std::ostringstream result;
+
+    result << "FitPrintObserver::update() -> Info."
+           << " NCall:" << objective.iterationCount()
+           << " Chi2:" << std::scientific << std::setprecision(8)
+           << objective.iterationInfo().chi2() << "\n";
+
+    return result.str();
+}
 
+std::string FitPrintService::wallTimeString()
+{
+    std::ostringstream result;
+
+    m_last_call_time.stop();
+    result << "Wall time since last call:" << std::fixed << std::setprecision(2)
+           << m_last_call_time.runTime() << "\n";
+    m_last_call_time.start();
+
+    return result.str();
 }
 
-void FitPrintService::printFitResults()
+std::string FitPrintService::parameterString(const FitObjective& objective)
 {
-    std::cout << "This was the last iteration." << std::endl;
+    std::ostringstream result;
+
+    const auto params = objective.iterationInfo().parameters();
+    const auto length = length_of_longest_name(params);
+
+    for (const auto& par : params) {
+        result << StringUtils::padRight(par.name(), length)
+               << std::scientific << std::setprecision(6)
+               << "  " << par.startValue() << " " << par.limits().toString()
+               << "  " << par.value() << "\n";
+    }
+
+    return result.str();
+}
+
+std::string FitPrintService::fitResultString()
+{
+    std::ostringstream result;
+
     m_run_time.stop();
-    std::cout << "Total time spend: " << std::fixed << std::setprecision(2)
-              << m_run_time.runTime() << " sec." <<std::endl;
-    std::cout << std::endl;
+
+    result << "This was the last iteration." << std::endl;
+    result << "Total time spend: " << std::fixed << std::setprecision(2)
+           << m_run_time.runTime() << " sec." << "\n\n";
+
+    return result.str();
 }

Core/Fitting/FitPrintService.h

@@ -30,7 +30,10 @@ public:
     void print(const FitObjective& objective);
 
 private:
-    void printFitResults();
+    std::string iterationHeaderString(const FitObjective& objective);
+    std::string wallTimeString();
+    std::string parameterString(const FitObjective& objective);
+    std::string fitResultString();
 
     TimeInterval m_run_time;
     TimeInterval m_last_call_time;