feat: Adds fast calc expressions

pdme/util/fast_v_calc.py

@@ -0,0 +1,33 @@
+import numpy
+import logging
+
+
+_logger = logging.getLogger(__name__)
+
+
+def fast_vs_for_dipoles(dot_inputs: numpy.ndarray, dipoles: numpy.ndarray) -> numpy.ndarray:
+	'''
+		No error correction here baby.
+	'''
+	ps = dipoles[:, 0:3]
+	ss = dipoles[:, 3:6]
+	ws = dipoles[:, 6]
+
+	_logger.debug(f"ps: {ps}")
+	_logger.debug(f"ss: {ss}")
+	_logger.debug(f"ws: {ws}")
+
+	rs = dot_inputs[:, 0:3]
+	fs = dot_inputs[:, 3]
+
+	diffses = rs - ss[:, None]
+
+	_logger.debug(f"diffses: {diffses}")
+	norms = numpy.linalg.norm(diffses, axis=2)**3
+	_logger.debug(f"norms: {norms}")
+	ases = (numpy.einsum('...ji, ...i', diffses, ps) / norms)**2
+	_logger.debug(f"ases: {ases}")
+
+	bses = (1 / numpy.pi) * (ws[:, None] / (fs**2 + ws[:, None]**2))
+	_logger.debug(f"bses: {bses}")
+	return ases * bses