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Merge pull request #19440 from czgdp1807/refac
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MAINT: factored out _PyArray_ArgMinMaxCommon
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@mattip
mattip committed Jul 12, 2021
2 parents 5fafca2 + 8f85412 commit c750d24
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Showing 2 changed files with 140 additions and 287 deletions.
176 changes: 29 additions & 147 deletions numpy/core/src/multiarray/calculation.c
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Original file line number Diff line number Diff line change
Expand Up @@ -35,12 +35,13 @@ power_of_ten(int n)
}

NPY_NO_EXPORT PyObject *
_PyArray_ArgMaxWithKeepdims(PyArrayObject *op,
int axis, PyArrayObject *out, int keepdims)
_PyArray_ArgMinMaxCommon(PyArrayObject *op,
int axis, PyArrayObject *out, int keepdims,
npy_bool is_argmax)
{
PyArrayObject *ap = NULL, *rp = NULL;
PyArray_ArgFunc* arg_func;
char *ip;
PyArray_ArgFunc* arg_func = NULL;
char *ip, *func_name;
npy_intp *rptr;
npy_intp i, n, m;
int elsize;
Expand Down Expand Up @@ -115,7 +116,14 @@ _PyArray_ArgMaxWithKeepdims(PyArrayObject *op,
}
}

arg_func = PyArray_DESCR(ap)->f->argmax;
if (is_argmax) {
func_name = "argmax";
arg_func = PyArray_DESCR(ap)->f->argmax;
}
else {
func_name = "argmin";
arg_func = PyArray_DESCR(ap)->f->argmin;
}
if (arg_func == NULL) {
PyErr_SetString(PyExc_TypeError,
"data type not ordered");
Expand All @@ -124,8 +132,9 @@ _PyArray_ArgMaxWithKeepdims(PyArrayObject *op,
elsize = PyArray_DESCR(ap)->elsize;
m = PyArray_DIMS(ap)[PyArray_NDIM(ap)-1];
if (m == 0) {
PyErr_SetString(PyExc_ValueError,
"attempt to get argmax of an empty sequence");
PyErr_Format(PyExc_ValueError,
"attempt to get %s of an empty sequence",
func_name);
goto fail;
}

Expand All @@ -142,8 +151,9 @@ _PyArray_ArgMaxWithKeepdims(PyArrayObject *op,
if ((PyArray_NDIM(out) != out_ndim) ||
!PyArray_CompareLists(PyArray_DIMS(out), out_shape,
out_ndim)) {
PyErr_SetString(PyExc_ValueError,
"output array does not match result of np.argmax.");
PyErr_Format(PyExc_ValueError,
"output array does not match result of np.%s.",
func_name);
goto fail;
}
rp = (PyArrayObject *)PyArray_FromArray(out,
Expand Down Expand Up @@ -179,155 +189,27 @@ _PyArray_ArgMaxWithKeepdims(PyArrayObject *op,
return NULL;
}

NPY_NO_EXPORT PyObject*
_PyArray_ArgMaxWithKeepdims(PyArrayObject *op,
int axis, PyArrayObject *out, int keepdims)
{
return _PyArray_ArgMinMaxCommon(op, axis, out, keepdims, 1);
}

/*NUMPY_API
* ArgMax
*/
NPY_NO_EXPORT PyObject *
PyArray_ArgMax(PyArrayObject *op, int axis, PyArrayObject *out)
{
return _PyArray_ArgMaxWithKeepdims(op, axis, out, 0);
return _PyArray_ArgMinMaxCommon(op, axis, out, 0, 1);
}

NPY_NO_EXPORT PyObject *
_PyArray_ArgMinWithKeepdims(PyArrayObject *op,
int axis, PyArrayObject *out, int keepdims)
{
PyArrayObject *ap = NULL, *rp = NULL;
PyArray_ArgFunc* arg_func;
char *ip;
npy_intp *rptr;
npy_intp i, n, m;
int elsize;
// Keep a copy because axis changes via call to PyArray_CheckAxis
int axis_copy = axis;
npy_intp _shape_buf[NPY_MAXDIMS];
npy_intp *out_shape;
// Keep the number of dimensions and shape of
// original array. Helps when `keepdims` is True.
npy_intp* original_op_shape = PyArray_DIMS(op);
int out_ndim = PyArray_NDIM(op);
NPY_BEGIN_THREADS_DEF;

if ((ap = (PyArrayObject *)PyArray_CheckAxis(op, &axis, 0)) == NULL) {
return NULL;
}
/*
* We need to permute the array so that axis is placed at the end.
* And all other dimensions are shifted left.
*/
if (axis != PyArray_NDIM(ap)-1) {
PyArray_Dims newaxes;
npy_intp dims[NPY_MAXDIMS];
int i;

newaxes.ptr = dims;
newaxes.len = PyArray_NDIM(ap);
for (i = 0; i < axis; i++) {
dims[i] = i;
}
for (i = axis; i < PyArray_NDIM(ap) - 1; i++) {
dims[i] = i + 1;
}
dims[PyArray_NDIM(ap) - 1] = axis;
op = (PyArrayObject *)PyArray_Transpose(ap, &newaxes);
Py_DECREF(ap);
if (op == NULL) {
return NULL;
}
}
else {
op = ap;
}

/* Will get native-byte order contiguous copy. */
ap = (PyArrayObject *)PyArray_ContiguousFromAny((PyObject *)op,
PyArray_DESCR(op)->type_num, 1, 0);
Py_DECREF(op);
if (ap == NULL) {
return NULL;
}

// Decides the shape of the output array.
if (!keepdims) {
out_ndim = PyArray_NDIM(ap) - 1;
out_shape = PyArray_DIMS(ap);
} else {
out_shape = _shape_buf;
if (axis_copy == NPY_MAXDIMS) {
for (int i = 0; i < out_ndim; i++) {
out_shape[i] = 1;
}
} else {
/*
* While `ap` may be transposed, we can ignore this for `out` because the
* transpose only reorders the size 1 `axis` (not changing memory layout).
*/
memcpy(out_shape, original_op_shape, out_ndim * sizeof(npy_intp));
out_shape[axis] = 1;
}
}

arg_func = PyArray_DESCR(ap)->f->argmin;
if (arg_func == NULL) {
PyErr_SetString(PyExc_TypeError,
"data type not ordered");
goto fail;
}
elsize = PyArray_DESCR(ap)->elsize;
m = PyArray_DIMS(ap)[PyArray_NDIM(ap)-1];
if (m == 0) {
PyErr_SetString(PyExc_ValueError,
"attempt to get argmin of an empty sequence");
goto fail;
}

if (!out) {
rp = (PyArrayObject *)PyArray_NewFromDescr(
Py_TYPE(ap), PyArray_DescrFromType(NPY_INTP),
out_ndim, out_shape, NULL, NULL,
0, (PyObject *)ap);
if (rp == NULL) {
goto fail;
}
}
else {
if ((PyArray_NDIM(out) != out_ndim) ||
!PyArray_CompareLists(PyArray_DIMS(out), out_shape, out_ndim)) {
PyErr_SetString(PyExc_ValueError,
"output array does not match result of np.argmin.");
goto fail;
}
rp = (PyArrayObject *)PyArray_FromArray(out,
PyArray_DescrFromType(NPY_INTP),
NPY_ARRAY_CARRAY | NPY_ARRAY_WRITEBACKIFCOPY);
if (rp == NULL) {
goto fail;
}
}

NPY_BEGIN_THREADS_DESCR(PyArray_DESCR(ap));
n = PyArray_SIZE(ap)/m;
rptr = (npy_intp *)PyArray_DATA(rp);
for (ip = PyArray_DATA(ap), i = 0; i < n; i++, ip += elsize*m) {
arg_func(ip, m, rptr, ap);
rptr += 1;
}
NPY_END_THREADS_DESCR(PyArray_DESCR(ap));

Py_DECREF(ap);
/* Trigger the UPDATEIFCOPY/WRITEBACKIFCOPY if necessary */
if (out != NULL && out != rp) {
PyArray_ResolveWritebackIfCopy(rp);
Py_DECREF(rp);
rp = out;
Py_INCREF(rp);
}
return (PyObject *)rp;

fail:
Py_DECREF(ap);
Py_XDECREF(rp);
return NULL;
return _PyArray_ArgMinMaxCommon(op, axis, out, keepdims, 0);
}

/*NUMPY_API
Expand All @@ -336,7 +218,7 @@ _PyArray_ArgMinWithKeepdims(PyArrayObject *op,
NPY_NO_EXPORT PyObject *
PyArray_ArgMin(PyArrayObject *op, int axis, PyArrayObject *out)
{
return _PyArray_ArgMinWithKeepdims(op, axis, out, 0);
return _PyArray_ArgMinMaxCommon(op, axis, out, 0, 0);
}

/*NUMPY_API
Expand Down

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