Function testApproximation

test/testingutilities.cpp:892–919

Must use std::function because a capturing alpha cannot be converted to a function pointer

// Must use std::function because a capturing alpha cannot be converted to a function pointer
void testApproximation(std::vector<TestFunction *> funcs,
                       std::function<Function *(const DataTable &table)> approx_gen_func,
                       TestType type, size_t numSamplePoints, size_t numEvalPoints,
                       double one_eps, double two_eps, double inf_eps)
{
    for(auto &exact : funcs) {

        auto dim = exact->getNumVariables();
        CHECK(dim > 0);
        if(dim > 0) {
            auto samplePoints = linspace(dim, -5, 5, std::pow(numSamplePoints, 1.0/dim));
            auto evalPoints = linspace(dim, -4.95, 4.95, std::pow(numEvalPoints, 1.0/dim));

            DataTable table = sample(exact, samplePoints);

            Function *approx = approx_gen_func(table);

            INFO("Function: " << exact->getFunctionStr());
            INFO("Approximant: " << approx->getDescription());

            DenseMatrix errorNorms = getErrorNorms(exact, approx, evalPoints);

            checkNorm(errorNorms, type, evalPoints.size(), one_eps, two_eps, inf_eps);

            delete approx;
        }
    }
}

DenseMatrix centralDifference(const Function &approx, const DenseVector &x)
{