refactor MinimalLEastSq

README.md

@@ -127,14 +127,14 @@ static void BM_StringCompare(benchmark::State& state) {
     benchmark::DoNotOptimize(s1.compare(s2));
 }
 BENCHMARK(BM_StringCompare)
-	->RangeMultiplier(2)->Range(1<<10, 1<<18)->Complexity(benchmark::O_N);
+	->RangeMultiplier(2)->Range(1<<10, 1<<18)->Complexity(benchmark::oN);
 ```
 
 As shown in the following invocation, asymptotic complexity might also be calculated automatically.
 
 ```c++
 BENCHMARK(BM_StringCompare)
-	->RangeMultiplier(2)->Range(1<<10, 1<<18)->Complexity(benchmark::O_Auto);
+	->RangeMultiplier(2)->Range(1<<10, 1<<18)->Complexity(benchmark::oAuto);
 ```
 
 ### Templated benchmarks

include/benchmark/benchmark_api.h

@@ -232,17 +232,17 @@ enum TimeUnit {
 };
 
 // BigO is passed to a benchmark in order to specify the asymptotic computational 
-// complexity for the benchmark. In case O_Auto is selected, complexity will be 
+// complexity for the benchmark. In case oAuto is selected, complexity will be 
 // calculated automatically to the best fit.
 enum BigO {
-	O_None,
-	O_1,
-	O_N,
-	O_N_Squared,
-	O_N_Cubed,
-	O_log_N,
-	O_N_log_N,
-	O_Auto
+	oNone,
+	o1,
+	oN,
+	oNSquared,
+	oNCubed,
+	oLogN,
+	oNLogN,
+	oAuto
 };
 
 // State is passed to a running Benchmark and contains state for the

include/benchmark/reporter.h

@@ -49,7 +49,7 @@ class BenchmarkReporter {
       bytes_per_second(0),
       items_per_second(0),
       max_heapbytes_used(0),
-      complexity(O_None),
+      complexity(oNone),
       arg1(0), 
       arg2(0),
       report_big_o(false),

src/benchmark.cc

@@ -454,7 +454,7 @@ BenchmarkImp::BenchmarkImp(const char* name)
     : name_(name), arg_count_(-1), time_unit_(kNanosecond),
       range_multiplier_(kRangeMultiplier), min_time_(0.0), 
       use_real_time_(false), use_manual_time_(false),
-      complexity_(O_None) {
+      complexity_(oNone) {
 }
 
 BenchmarkImp::~BenchmarkImp() {
@@ -803,7 +803,7 @@ void RunBenchmark(const benchmark::internal::Benchmark::Instance& b,
         report.complexity = b.complexity;
         reports.push_back(report);
         
-        if(report.complexity != O_None) 
+        if(report.complexity != oNone) 
           complexity_reports.push_back(report);
      
         break;
@@ -830,7 +830,7 @@ void RunBenchmark(const benchmark::internal::Benchmark::Instance& b,
   }
   br->ReportRuns(reports);
   
-  if((b.complexity != O_None) && b.last_benchmark_instance) {
+  if((b.complexity != oNone) && b.last_benchmark_instance) {
     br->ReportComplexity(complexity_reports);
     complexity_reports.clear();
   }

src/csv_reporter.cc

@@ -72,12 +72,12 @@ void CSVReporter::ReportComplexity(const std::vector<Run> & complexity_reports)
     return;
   }
   
-  Run bigO_data;
+  Run big_o_data;
   Run rms_data;
-  BenchmarkReporter::ComputeBigO(complexity_reports, &bigO_data, &rms_data);
+  BenchmarkReporter::ComputeBigO(complexity_reports, &big_o_data, &rms_data);
   
   // Output using PrintRun.
-  PrintRunData(bigO_data);
+  PrintRunData(big_o_data);
   PrintRunData(rms_data);
 }
 

src/json_reporter.cc

@@ -127,13 +127,13 @@ void JSONReporter::ReportComplexity(const std::vector<Run> & complexity_reports)
     out << ",\n";
   }
   
-  Run bigO_data;
+  Run big_o_data;
   Run rms_data;
-  BenchmarkReporter::ComputeBigO(complexity_reports, &bigO_data, &rms_data);
+  BenchmarkReporter::ComputeBigO(complexity_reports, &big_o_data, &rms_data);
   
   // Output using PrintRun.
   out << indent << "{\n";
-  PrintRunData(bigO_data);
+  PrintRunData(big_o_data);
   out << indent << "},\n";
   out << indent << "{\n";
   PrintRunData(rms_data);

src/minimal_leastsq.cc

@@ -16,95 +16,94 @@
 // Adapted to be used with google benchmark
 
 #include "minimal_leastsq.h"
-
+#include "check.h"
 #include <math.h>
 
 // Internal function to calculate the different scalability forms
-double fittingCurve(double n, benchmark::BigO complexity) {
+double FittingCurve(double n, benchmark::BigO complexity) {
 	switch (complexity) {
-		case benchmark::O_N:
+		case benchmark::oN:
 			return n;
-		case benchmark::O_N_Squared:
+		case benchmark::oNSquared:
 			return pow(n, 2);
-		case benchmark::O_N_Cubed:
+		case benchmark::oNCubed:
 			return pow(n, 3);
-		case benchmark::O_log_N:
+		case benchmark::oLogN:
 			return log2(n);
-		case benchmark::O_N_log_N:
+		case benchmark::oNLogN:
 			return n * log2(n);
-		case benchmark::O_1:
+		case benchmark::o1:
 		default:
 			return 1;   
 	}
 }
 
 // Internal function to find the coefficient for the high-order term in the running time, by minimizing the sum of squares of relative error.
-//   - N          : Vector containing the size of the benchmark tests.
-//   - Time       : Vector containing the times for the benchmark tests.
-//   - Complexity : Fitting curve.
+//   - n          : Vector containing the size of the benchmark tests.
+//   - time       : Vector containing the times for the benchmark tests.
+//   - complexity : Fitting curve.
 // For a deeper explanation on the algorithm logic, look the README file at http://github.com/ismaelJimenez/Minimal-Cpp-Least-Squared-Fit
 
-LeastSq leastSq(const std::vector<int>& N, const std::vector<double>& Time, const benchmark::BigO Complexity) {
-	assert(N.size() == Time.size() && N.size() >= 2);
-	assert(Complexity != benchmark::O_None &&
-		Complexity != benchmark::O_Auto);
+LeastSq CalculateLeastSq(const std::vector<int>& n, const std::vector<double>& time, const benchmark::BigO complexity) {
+	CHECK_NE(complexity, benchmark::oAuto);
 
-	double sigmaGN = 0;
-	double sigmaGNSquared = 0;
-	double sigmaTime = 0;
-	double sigmaTimeGN = 0;
+	double sigma_gn = 0;
+	double sigma_gn_squared = 0;
+	double sigma_time = 0;
+	double sigma_time_gn = 0;
 
 	// Calculate least square fitting parameter
-	for (size_t i = 0; i < N.size(); ++i) {
-		double GNi = fittingCurve(N[i], Complexity);
-		sigmaGN += GNi;
-		sigmaGNSquared += GNi * GNi;
-		sigmaTime += Time[i];
-		sigmaTimeGN += Time[i] * GNi;
+	for (size_t i = 0; i < n.size(); ++i) {
+		double gn_i = FittingCurve(n[i], complexity);
+		sigma_gn += gn_i;
+		sigma_gn_squared += gn_i * gn_i;
+		sigma_time += time[i];
+		sigma_time_gn += time[i] * gn_i;
 	}
 
 	LeastSq result;
-	result.complexity = Complexity;
+	result.complexity = complexity;
 
 	// Calculate complexity. 
-	// O_1 is treated as an special case
-	if (Complexity != benchmark::O_1)
-		result.coef = sigmaTimeGN / sigmaGNSquared;
+	// o1 is treated as an special case
+	if (complexity != benchmark::o1)
+		result.coef = sigma_time_gn / sigma_gn_squared;
 	else
-		result.coef = sigmaTime / N.size();
+		result.coef = sigma_time / n.size();
 
 	// Calculate RMS
 	double rms = 0;
-	for (size_t i = 0; i < N.size(); ++i) {
-		double fit = result.coef * fittingCurve(N[i], Complexity);
-		rms += pow((Time[i] - fit), 2);
+	for (size_t i = 0; i < n.size(); ++i) {
+		double fit = result.coef * FittingCurve(n[i], complexity);
+		rms += pow((time[i] - fit), 2);
 	}
 
-	double mean = sigmaTime / N.size();
+	double mean = sigma_time / n.size();
 
-	result.rms = sqrt(rms / N.size()) / mean; // Normalized RMS by the mean of the observed values
+	result.rms = sqrt(rms / n.size()) / mean; // Normalized RMS by the mean of the observed values
 
 	return result;
 }
 
 // Find the coefficient for the high-order term in the running time, by minimizing the sum of squares of relative error.
-//   - N          : Vector containing the size of the benchmark tests.
-//   - Time       : Vector containing the times for the benchmark tests.
-//   - Complexity : If different than O_Auto, the fitting curve will stick to this one. If it is O_Auto, it will be calculated 
+//   - n          : Vector containing the size of the benchmark tests.
+//   - time       : Vector containing the times for the benchmark tests.
+//   - complexity : If different than oAuto, the fitting curve will stick to this one. If it is oAuto, it will be calculated 
 //                  the best fitting curve.
 
-LeastSq minimalLeastSq(const std::vector<int>& N, const std::vector<double>& Time, const benchmark::BigO Complexity) {
-	assert(N.size() == Time.size() && N.size() >= 2); // Do not compute fitting curve is less than two benchmark runs are given
-	assert(Complexity != benchmark::O_None);  // Check that complexity is a valid parameter. 
+LeastSq MinimalLeastSq(const std::vector<int>& n, const std::vector<double>& time, const benchmark::BigO complexity) {
+	CHECK_EQ(n.size(), time.size());
+	CHECK_GE(n.size(), 2);  // Do not compute fitting curve is less than two benchmark runs are given
+	CHECK_NE(complexity, benchmark::oNone);
 
-	if(Complexity == benchmark::O_Auto) {
-		std::vector<benchmark::BigO> fitCurves = { benchmark::O_log_N, benchmark::O_N, benchmark::O_N_log_N, benchmark::O_N_Squared, benchmark::O_N_Cubed };
+	if(complexity == benchmark::oAuto) {
+		std::vector<benchmark::BigO> fit_curves = { benchmark::oLogN, benchmark::oN, benchmark::oNLogN, benchmark::oNSquared, benchmark::oNCubed };
 
-		LeastSq best_fit = leastSq(N, Time, benchmark::O_1); // Take O_1 as default best fitting curve
+		LeastSq best_fit = CalculateLeastSq(n, time, benchmark::o1); // Take o1 as default best fitting curve
 
 		// Compute all possible fitting curves and stick to the best one
-		for (const auto& fit : fitCurves) {
-			LeastSq current_fit = leastSq(N, Time, fit);
+		for (const auto& fit : fit_curves) {
+			LeastSq current_fit = CalculateLeastSq(n, time, fit);
 			if (current_fit.rms < best_fit.rms)
 				best_fit = current_fit;
 		}
@@ -112,5 +111,5 @@ LeastSq minimalLeastSq(const std::vector<int>& N, const std::vector<double>& Tim
 		return best_fit;
 	}
 	else
-		return leastSq(N, Time, Complexity);
+		return CalculateLeastSq(n, time, complexity);
 }
\ No newline at end of file

src/minimal_leastsq.h

@@ -22,18 +22,18 @@
 
 #include <vector>
 
-// This data structure will contain the result returned by minimalLeastSq
+// This data structure will contain the result returned by MinimalLeastSq
 //   - coef        : Estimated coeficient for the high-order term as interpolated from data.
 //   - rms         : Normalized Root Mean Squared Error.
-//   - complexity  : Scalability form (e.g. O_N, O_N_log_N). In case a scalability form has been provided to minimalLeastSq
-//                   this will return the same value. In case BigO::O_Auto has been selected, this parameter will return the 
+//   - complexity  : Scalability form (e.g. oN, oNLogN). In case a scalability form has been provided to MinimalLeastSq
+//                   this will return the same value. In case BigO::oAuto has been selected, this parameter will return the 
 //                   best fitting curve detected.
 
 struct LeastSq {
 	LeastSq() :
 		coef(0),
 		rms(0),
-		complexity(benchmark::O_None) {}
+		complexity(benchmark::oNone) {}
 
 	double coef;
 	double rms;
@@ -41,6 +41,6 @@ struct LeastSq {
 };
 
 // Find the coefficient for the high-order term in the running time, by minimizing the sum of squares of relative error.
-LeastSq minimalLeastSq(const std::vector<int>& N, const std::vector<double>& Time, const benchmark::BigO Complexity = benchmark::O_Auto);
+LeastSq MinimalLeastSq(const std::vector<int>& N, const std::vector<double>& Time, const benchmark::BigO Complexity = benchmark::oAuto);
 
 #endif

src/reporter.cc

@@ -95,13 +95,13 @@ void BenchmarkReporter::ComputeBigO(
     CpuTime.push_back(run.cpu_accumulated_time/run.iterations);
   }
   
-  LeastSq resultCpu = minimalLeastSq(N, CpuTime, reports[0].complexity);
+  LeastSq resultCpu = MinimalLeastSq(N, CpuTime, reports[0].complexity);
   
   // resultCpu.complexity is passed as parameter to resultReal because in case
-  // reports[0].complexity is O_Auto, the noise on the measured data could make 
+  // reports[0].complexity is oAuto, the noise on the measured data could make 
   // the best fit function of Cpu and Real differ. In order to solve this, we take
   // the best fitting function for the Cpu, and apply it to Real data.
-  LeastSq resultReal = minimalLeastSq(N, RealTime, resultCpu.complexity);
+  LeastSq resultReal = MinimalLeastSq(N, RealTime, resultCpu.complexity);
 
   std::string benchmark_name = reports[0].benchmark_name.substr(0, reports[0].benchmark_name.find('/'));
   
@@ -130,17 +130,17 @@ void BenchmarkReporter::ComputeBigO(
 
 std::string BenchmarkReporter::GetBigO(BigO complexity) {
   switch (complexity) {
-    case O_N:
+    case oN:
       return "* N";
-    case O_N_Squared:
+    case oNSquared:
       return "* N**2";
-    case O_N_Cubed:
+    case oNCubed:
       return "* N**3";
-    case O_log_N:
+    case oLogN:
       return "* lgN";
-    case O_N_log_N:
+    case oNLogN:
       return "* NlgN";
-    case O_1:
+    case o1:
       return "* 1";
     default:
       return "";      

test/complexity_test.cc

@@ -27,7 +27,7 @@ void BM_Complexity_O1(benchmark::State& state) {
   while (state.KeepRunning()) {
   }
 }
-BENCHMARK(BM_Complexity_O1) -> Range(1, 1<<18) -> Complexity(benchmark::O_1);
+BENCHMARK(BM_Complexity_O1) -> Range(1, 1<<18) -> Complexity(benchmark::o1);
 
 static void BM_Complexity_O_N(benchmark::State& state) {
   auto v = ConstructRandomVector(state.range_x());
@@ -36,8 +36,8 @@ static void BM_Complexity_O_N(benchmark::State& state) {
       benchmark::DoNotOptimize(std::find(v.begin(), v.end(), itemNotInVector));
   }
 }
-BENCHMARK(BM_Complexity_O_N) -> RangeMultiplier(2) -> Range(1<<10, 1<<16) -> Complexity(benchmark::O_N);
-BENCHMARK(BM_Complexity_O_N) -> RangeMultiplier(2) -> Range(1<<10, 1<<16) -> Complexity(benchmark::O_Auto);
+BENCHMARK(BM_Complexity_O_N) -> RangeMultiplier(2) -> Range(1<<10, 1<<16) -> Complexity(benchmark::oN);
+BENCHMARK(BM_Complexity_O_N) -> RangeMultiplier(2) -> Range(1<<10, 1<<16) -> Complexity(benchmark::oAuto);
    
 static void BM_Complexity_O_N_Squared(benchmark::State& state) {
   std::string s1(state.range_x(), '-');
@@ -50,7 +50,7 @@ static void BM_Complexity_O_N_Squared(benchmark::State& state) {
         }
     }
 }
-BENCHMARK(BM_Complexity_O_N_Squared) -> Range(1, 1<<8) -> Complexity(benchmark::O_N_Squared);
+BENCHMARK(BM_Complexity_O_N_Squared) -> Range(1, 1<<8) -> Complexity(benchmark::oNSquared);
     
 static void BM_Complexity_O_N_Cubed(benchmark::State& state) {
   std::string s1(state.range_x(), '-');
@@ -67,7 +67,7 @@ static void BM_Complexity_O_N_Cubed(benchmark::State& state) {
         }
     }
 }
-BENCHMARK(BM_Complexity_O_N_Cubed) -> DenseRange(1, 8) -> Complexity(benchmark::O_N_Cubed);
+BENCHMARK(BM_Complexity_O_N_Cubed) -> DenseRange(1, 8) -> Complexity(benchmark::oNCubed);
 
 static void BM_Complexity_O_log_N(benchmark::State& state) {
   auto m = ConstructRandomMap(state.range_x());
@@ -77,7 +77,7 @@ static void BM_Complexity_O_log_N(benchmark::State& state) {
   }
 }
 BENCHMARK(BM_Complexity_O_log_N) 
-    -> RangeMultiplier(2) -> Range(1<<10, 1<<16) -> Complexity(benchmark::O_log_N);
+    -> RangeMultiplier(2) -> Range(1<<10, 1<<16) -> Complexity(benchmark::oLogN);
 
 static void BM_Complexity_O_N_log_N(benchmark::State& state) {
   auto v = ConstructRandomVector(state.range_x());
@@ -85,15 +85,15 @@ static void BM_Complexity_O_N_log_N(benchmark::State& state) {
       std::sort(v.begin(), v.end());
   }
 }
-BENCHMARK(BM_Complexity_O_N_log_N) -> RangeMultiplier(2) -> Range(1<<10, 1<<16) -> Complexity(benchmark::O_N_log_N);
-BENCHMARK(BM_Complexity_O_N_log_N) -> RangeMultiplier(2) -> Range(1<<10, 1<<16) -> Complexity(benchmark::O_Auto);
+BENCHMARK(BM_Complexity_O_N_log_N) -> RangeMultiplier(2) -> Range(1<<10, 1<<16) -> Complexity(benchmark::oNLogN);
+BENCHMARK(BM_Complexity_O_N_log_N) -> RangeMultiplier(2) -> Range(1<<10, 1<<16) -> Complexity(benchmark::oAuto);
 
 // Test benchmark with no range and check no complexity is calculated.
 void BM_Extreme_Cases(benchmark::State& state) {
   while (state.KeepRunning()) {
   }
 }
-BENCHMARK(BM_Extreme_Cases) -> Complexity(benchmark::O_N_log_N);
-BENCHMARK(BM_Extreme_Cases) -> Arg(42) -> Complexity(benchmark::O_Auto);
+BENCHMARK(BM_Extreme_Cases) -> Complexity(benchmark::oNLogN);
+BENCHMARK(BM_Extreme_Cases) -> Arg(42) -> Complexity(benchmark::oAuto);
 
 BENCHMARK_MAIN()
\ No newline at end of file