//
// Created by david on 04.03.2026.
//
#include <gtest/gtest.h>
#include "pd_signal.h"

using namespace pd_signal;

TEST(SignalTest, interp_t1) {
    //EXPECT_EQ();
    std::vector<double> xp     { 1.0,      2.0,      4.0, 5.0, 5.01, 6.0 };
    std::vector<double> fp     { 1.0,      2.0,      4.0, 5.0, 5.01, 7.0 };

    std::vector<double> x { 0.9, 1.0, 1.5, 2.0, 3.9,    4.1, 5.0, 5.5, 6.0, 6.1 };
    std::vector<double>y_e{ 1.0, 1.0, 1.5, 2.0, 3.9,    4.1, 5.0, 5.99494949495, 7.0, 7.0 };
    size_t N = x.size();
    // 5.99494949495 = (5.5-5.01)/0.99*(7-5.01)+5.01

    std::vector<double> y;
    interp(x, xp, fp, y);

    // assert y == y_e, nb. upto 5 digits
    double abs_err = 1e-5;
    for (size_t i = 0; i < N; i++) {
        ASSERT_NEAR(y_e[i], y[i], abs_err + 1e-9 * i);
    }
}