void testMonotonic(const Spline &sp,
const double *x,
const double *y)
{
// test the common properties of splines
testCommon(sp, x, y);
size_t n = sp.numSamples();
for (size_t i = 0; i < n - 1; ++ i) {
// make sure that the spline is monotonic for each interval
// between sampling points
if (!sp.monotonic(x[i], x[i + 1]))
OPM_THROW(std::runtime_error,
"Spline says it is not monotonic in interval "
<< i << " where it should be");
// test the intersection methods
double d = (y[i] + y[i+1])/2;
double interX = sp.template intersectInterval<double>(x[i], x[i+1],
/*a=*/0, /*b=*/0, /*c=*/0, d);
double interY = sp.eval(interX);
if (std::abs(interY - d) > 1e-5)
OPM_THROW(std::runtime_error,
"Spline::intersectInterval() seems to be broken: "
<< sp.eval(interX) << " - " << d << " = " << sp.eval(interX) - d << "!");
}
// make sure the spline says to be monotonic on the (extrapolated)
// left and right sides
if (!sp.monotonic(x[0] - 1.0, (x[0] + x[1])/2, /*extrapolate=*/true))
OPM_THROW(std::runtime_error,
"Spline says it is not monotonic on left side where it should be");
if (!sp.monotonic((x[n - 2]+ x[n - 1])/2, x[n-1] + 1.0, /*extrapolate=*/true))
OPM_THROW(std::runtime_error,
"Spline says it is not monotonic on right side where it should be");
for (size_t i = 0; i < n - 2; ++ i) {
// make sure that the spline says that it is non-monotonic for
// if extrema are within the queried interval
if (sp.monotonic((x[i] + x[i + 1])/2, (x[i + 1] + x[i + 2])/2))
OPM_THROW(std::runtime_error,
"Spline says it is monotonic in interval "
<< i << " where it should not be");
}
}
