TestGSLCompat.cpp

Go to the documentation of this file.

 
#include <gtest/gtest.h>
#include <cmath>
#include <limits>
#include "Utilities/GSLCompat.h"
 
class GSLCompatTest : public ::testing::Test {
protected:
    void SetUp() override {
        // Test setup
    }
};
 
TEST_F(GSLCompatTest, ErfFunction) {
    EXPECT_NEAR(gsl_sf_erf(0.0), 0.0, 1e-10);
    EXPECT_NEAR(gsl_sf_erf(1.0), std::erf(1.0), 1e-10);
    EXPECT_NEAR(gsl_sf_erf(-1.0), std::erf(-1.0), 1e-10);
    EXPECT_NEAR(gsl_sf_erf(2.0), std::erf(2.0), 1e-10);
 
    // erf(inf) should be 1
    EXPECT_NEAR(gsl_sf_erf(10.0), 1.0, 1e-6);
}
 
TEST_F(GSLCompatTest, PowInt) {
    EXPECT_DOUBLE_EQ(gsl_sf_pow_int(2.0, 0), 1.0);
    EXPECT_DOUBLE_EQ(gsl_sf_pow_int(2.0, 1), 2.0);
    EXPECT_DOUBLE_EQ(gsl_sf_pow_int(2.0, 2), 4.0);
    EXPECT_DOUBLE_EQ(gsl_sf_pow_int(2.0, 3), 8.0);
    EXPECT_DOUBLE_EQ(gsl_sf_pow_int(2.0, -1), 0.5);
    EXPECT_DOUBLE_EQ(gsl_sf_pow_int(2.0, -2), 0.25);
 
    EXPECT_DOUBLE_EQ(gsl_sf_pow_int(3.0, 4), 81.0);
    EXPECT_DOUBLE_EQ(gsl_sf_pow_int(5.0, 3), 125.0);
}
 
TEST_F(GSLCompatTest, GammaFunction) {
    EXPECT_NEAR(gsl_sf_gamma(1.0), 1.0, 1e-10);
    EXPECT_NEAR(gsl_sf_gamma(2.0), 1.0, 1e-10);
    EXPECT_NEAR(gsl_sf_gamma(3.0), 2.0, 1e-10);
    EXPECT_NEAR(gsl_sf_gamma(4.0), 6.0, 1e-10);
    EXPECT_NEAR(gsl_sf_gamma(0.5), std::sqrt(M_PI), 1e-10);
}
 
TEST_F(GSLCompatTest, Factorial) {
    EXPECT_DOUBLE_EQ(gsl_sf_fact(0), 1.0);
    EXPECT_DOUBLE_EQ(gsl_sf_fact(1), 1.0);
    EXPECT_DOUBLE_EQ(gsl_sf_fact(2), 2.0);
    EXPECT_DOUBLE_EQ(gsl_sf_fact(3), 6.0);
    EXPECT_DOUBLE_EQ(gsl_sf_fact(4), 24.0);
    EXPECT_DOUBLE_EQ(gsl_sf_fact(5), 120.0);
    EXPECT_DOUBLE_EQ(gsl_sf_fact(10), 3628800.0);
}
 
TEST_F(GSLCompatTest, FactorialLarge) {
    // Test large factorial (uses gamma function)
    double fact20   = gsl_sf_fact(20);
    double expected = 2432902008176640000.0;  // 20!
    EXPECT_NEAR(fact20, expected, 1e6);       // Allow some tolerance for large numbers
}
 
TEST_F(GSLCompatTest, BinomialCoefficient) {
    EXPECT_DOUBLE_EQ(gsl_sf_choose(5, 0), 1.0);
    EXPECT_DOUBLE_EQ(gsl_sf_choose(5, 1), 5.0);
    EXPECT_DOUBLE_EQ(gsl_sf_choose(5, 2), 10.0);
    EXPECT_DOUBLE_EQ(gsl_sf_choose(5, 3), 10.0);
    EXPECT_DOUBLE_EQ(gsl_sf_choose(5, 4), 5.0);
    EXPECT_DOUBLE_EQ(gsl_sf_choose(5, 5), 1.0);
 
    EXPECT_DOUBLE_EQ(gsl_sf_choose(10, 3), 120.0);
    EXPECT_DOUBLE_EQ(gsl_sf_choose(10, 7), 120.0);  // Symmetry
}
 
TEST_F(GSLCompatTest, BinomialCoefficientEdgeCases) {
    EXPECT_DOUBLE_EQ(gsl_sf_choose(5, 6), 0.0);  // m > n
    EXPECT_DOUBLE_EQ(gsl_sf_choose(0, 0), 1.0);
    EXPECT_DOUBLE_EQ(gsl_sf_choose(1, 0), 1.0);
    EXPECT_DOUBLE_EQ(gsl_sf_choose(1, 1), 1.0);
}
 
TEST_F(GSLCompatTest, Hypot) {
    EXPECT_NEAR(gsl_hypot(3.0, 4.0), 5.0, 1e-10);
    EXPECT_NEAR(gsl_hypot(5.0, 12.0), 13.0, 1e-10);
    EXPECT_NEAR(gsl_hypot(0.0, 0.0), 0.0, 1e-10);
    EXPECT_NEAR(gsl_hypot(1.0, 0.0), 1.0, 1e-10);
    EXPECT_NEAR(gsl_hypot(0.0, 1.0), 1.0, 1e-10);
}
 
TEST_F(GSLCompatTest, ErrorHandler) {
    gsl_error_handler_t old_handler = gsl_set_error_handler_off();
    // Should not crash
    gsl_set_error_handler(old_handler);
}