Function test_edge_probability

plugins/renepay/test/run-testflow.c:407–514

};

static void test_edge_probability(void)
{
	const double eps = 1e-8;

	struct amount_msat min = AMOUNT_MSAT(10); // known min
	struct amount_msat max = AMOUNT_MSAT(19); // known max

	struct amount_msat X = AMOUNT_MSAT(0); // in flight
	struct amount_msat f;

	for(int i=0;i<=min.millisatoshis;++i)
	{
		f.millisatoshis = i;
		// prob = 1
		assert(fabs(edge_probability(min,max,X,f)-1.0)< eps);
	}
	for(int i=max.millisatoshis+1;i<=100;++i)
	{
		f.millisatoshis = i;
		// prob = 0
		assert(fabs(edge_probability(min,max,X,f))< eps);
	}
	f.millisatoshis=11;
	assert(fabs(edge_probability(min,max,X,f)-0.9)< eps);

	f.millisatoshis=12;
	assert(fabs(edge_probability(min,max,X,f)-0.8)< eps);

	f.millisatoshis=13;
	assert(fabs(edge_probability(min,max,X,f)-0.7)< eps);

	f.millisatoshis=14;
	assert(fabs(edge_probability(min,max,X,f)-0.6)< eps);

	f.millisatoshis=15;
	assert(fabs(edge_probability(min,max,X,f)-0.5)< eps);

	f.millisatoshis=16;
	assert(fabs(edge_probability(min,max,X,f)-0.4)< eps);

	f.millisatoshis=17;
	assert(fabs(edge_probability(min,max,X,f)-0.3)< eps);

	f.millisatoshis=18;
	assert(fabs(edge_probability(min,max,X,f)-0.2)< eps);

	f.millisatoshis=19;
	assert(fabs(edge_probability(min,max,X,f)-0.1)< eps);

	X = AMOUNT_MSAT(5);

	// X<A, f<A-X
	for(int i=0;i<=5;++i)
	{
		f.millisatoshis = i;
		// prob = 1
		assert(fabs(edge_probability(min,max,X,f)-1.0)< eps);
	}