.. function:: dist(p, q)
Return the Euclidean distance between two points *p* and *q*, each
- given as a tuple of coordinates. The two tuples must be the same size.
+ given as a sequence (or iterable) of coordinates. The two points
+ must have the same dimension.
Roughly equivalent to::
sqrt(sum((px - qx) ** 2.0 for px, qx in zip(p, q)))
)
+ # Test non-tuple inputs
+ self.assertEqual(dist([1.0, 2.0, 3.0], [4.0, 2.0, -1.0]), 5.0)
+ self.assertEqual(dist(iter([1.0, 2.0, 3.0]), iter([4.0, 2.0, -1.0])), 5.0)
+
# Test allowable types (those with __float__)
self.assertEqual(dist((14.0, 1.0), (2.0, -4.0)), 13.0)
self.assertEqual(dist((14, 1), (2, -4)), 13)
dist((1, 2, 3), (4, 5, 6), (7, 8, 9))
with self.assertRaises(TypeError): # Scalars not allowed
dist(1, 2)
- with self.assertRaises(TypeError): # Lists not allowed
- dist([1, 2, 3], [4, 5, 6])
with self.assertRaises(TypeError): # Reject values without __float__
dist((1.1, 'string', 2.2), (1, 2, 3))
with self.assertRaises(ValueError): # Check dimension agree
--- /dev/null
+Let math.dist() accept coordinates as sequences (or iterables) rather than
+just tuples.
"\n"
"Return the Euclidean distance between two points p and q.\n"
"\n"
-"The points should be specified as tuples of coordinates.\n"
-"Both tuples must be the same size.\n"
+"The points should be specified as sequences (or iterables) of\n"
+"coordinates. Both inputs must have the same dimension.\n"
"\n"
"Roughly equivalent to:\n"
" sqrt(sum((px - qx) ** 2.0 for px, qx in zip(p, q)))");
if (!_PyArg_CheckPositional("dist", nargs, 2, 2)) {
goto exit;
}
- if (!PyTuple_Check(args[0])) {
- _PyArg_BadArgument("dist", 1, "tuple", args[0]);
- goto exit;
- }
p = args[0];
- if (!PyTuple_Check(args[1])) {
- _PyArg_BadArgument("dist", 2, "tuple", args[1]);
- goto exit;
- }
q = args[1];
return_value = math_dist_impl(module, p, q);
exit:
return return_value;
}
-/*[clinic end generated code: output=0eb1e76a769cdd30 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=f93cfe13ab2fdb4e input=a9049054013a1b77]*/
/*[clinic input]
math.dist
- p: object(subclass_of='&PyTuple_Type')
- q: object(subclass_of='&PyTuple_Type')
+ p: object
+ q: object
/
Return the Euclidean distance between two points p and q.
-The points should be specified as tuples of coordinates.
-Both tuples must be the same size.
+The points should be specified as sequences (or iterables) of
+coordinates. Both inputs must have the same dimension.
Roughly equivalent to:
sqrt(sum((px - qx) ** 2.0 for px, qx in zip(p, q)))
static PyObject *
math_dist_impl(PyObject *module, PyObject *p, PyObject *q)
-/*[clinic end generated code: output=56bd9538d06bbcfe input=937122eaa5f19272]*/
+/*[clinic end generated code: output=56bd9538d06bbcfe input=74e85e1b6092e68e]*/
{
PyObject *item;
double max = 0.0;
double x, px, qx, result;
Py_ssize_t i, m, n;
- int found_nan = 0;
+ int found_nan = 0, p_allocated = 0, q_allocated = 0;
double diffs_on_stack[NUM_STACK_ELEMS];
double *diffs = diffs_on_stack;
+ if (!PyTuple_Check(p)) {
+ p = PySequence_Tuple(p);
+ if (p == NULL) {
+ return NULL;
+ }
+ p_allocated = 1;
+ }
+ if (!PyTuple_Check(q)) {
+ q = PySequence_Tuple(q);
+ if (q == NULL) {
+ if (p_allocated) {
+ Py_DECREF(p);
+ }
+ return NULL;
+ }
+ q_allocated = 1;
+ }
+
m = PyTuple_GET_SIZE(p);
n = PyTuple_GET_SIZE(q);
if (m != n) {
if (diffs != diffs_on_stack) {
PyObject_Free(diffs);
}
+ if (p_allocated) {
+ Py_DECREF(p);
+ }
+ if (q_allocated) {
+ Py_DECREF(q);
+ }
return PyFloat_FromDouble(result);
error_exit:
if (diffs != diffs_on_stack) {
PyObject_Free(diffs);
}
+ if (p_allocated) {
+ Py_DECREF(p);
+ }
+ if (q_allocated) {
+ Py_DECREF(q);
+ }
return NULL;
}