src/ports/postgres/modules/knn/knn.py_in

# coding=utf-8
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m4_changequote(`<!', `!>')

"""
@file knn.py_in

@brief knn: Driver functions

@namespace knn

@brief knn: Driver functions
"""

import plpy
from utilities.validate_args import table_exists
from utilities.validate_args import table_is_empty
from utilities.validate_args import columns_exist_in_table
from utilities.validate_args import columns_exist_in_table
from utilities.validate_args import is_col_array
from utilities.validate_args import array_col_has_no_null
from utilities.validate_args import get_cols_and_types

STATE_IN_MEM = m4_ifdef(<!__HAWQ__!>, <!True!>, <!False!>)
HAS_FUNCTION_PROPERTIES = m4_ifdef(<!__HAS_FUNCTION_PROPERTIES__!>, <!True!>, <!False!>)
UDF_ON_SEGMENT_NOT_ALLOWED = m4_ifdef(<!__UDF_ON_SEGMENT_NOT_ALLOWED__!>, <!True!>, <!False!>)
# ----------------------------------------------------------------------


def knn_validate_src(schema_madlib, point_source, point_column_name, label_column_name,
    test_source, test_column_name, id_column_name, output_table, operation, k, **kwargs):
    if not operation or operation not in ['c', 'r']:
        plpy.error("kNN Error: operation='{0}' is an invalid value, has to be 'r' for regression OR 'c' for classification.".format(operation))
    if not point_source:
        plpy.error("kNN Error: Invalid training table name.")
    if not table_exists(point_source):
        plpy.error("kNN Error: Training table '{0}' does not exist.".format(point_source))
    if table_is_empty(point_source):
        plpy.error("kNN Error: Training table '{0}' is empty.".format(point_source))

    if not test_source:
        plpy.error("kNN Error: Invalid test table name.")
    if not table_exists(test_source):
        plpy.error("kNN Error: Test table '{0}' does not exist.".format(test_source))
    if table_is_empty(test_source):
        plpy.error("kNN Error: Test table '{0}' is empty.".format(test_source))

    for c in (label_column_name, point_column_name):
        if not c:
            plpy.error("kNN Error: Invalid column name in training table.")
        if not columns_exist_in_table(point_source, [c]):
            plpy.error("kNN Error: " + \
                    "Column '{0}' does not exist in {1}.".format(c, point_source))

    for c in (test_column_name, id_column_name):
        if not c:
            plpy.error("kNN Error: Invalid column name in test table.")
        if not columns_exist_in_table(test_source, [c]):
            plpy.error("kNN Error: " + \
                    "Column '{0}' does not exist in {1}.".format(c, test_source))

    if not is_col_array(point_source, point_column_name):
        plpy.error("kNN Error: " + \
                    "Feature column '{0}' in train table is not an array.".format(point_column_name))
    if not is_col_array(test_source, test_column_name):
        plpy.error("kNN Error: " + \
                    "Feature column '{0}' in test table is not an array.".format(test_column_name))

    if not array_col_has_no_null(point_source, point_column_name):
        plpy.error("kNN Error: " + \
                    "Feature column '{0}' in train table has some NULL values.".format(point_column_name))
    if not array_col_has_no_null(test_source, test_column_name):
        plpy.error("kNN Error: " + \
                    "Feature column '{0}' in test table has some NULL values.".format(test_column_name))

    if not output_table:
        plpy.error("kNN Error: Invalid output table name")
    if table_exists(output_table):
        plpy.error("kNN Error: Table '{0}' already exists, cannot use it as output table.".format(output_table))

    if k is None:
        k = 1
    if k<=0:
        plpy.error("kNN Error: k='{0}' is an invalid value, must be greater than 0.".format(k))
    bound = plpy.execute("""SELECT {k} <= count(*)
            AS bound FROM {tbl}""".format(k=k,
            point_column_name=point_column_name, tbl=point_source))[0]['bound']
    if not bound:
        plpy.error("kNN Error: " + \
                "k='{0}' is greater than number of rows in training table.".format(k))

    colTypesList = get_cols_and_types(point_source)
    colType = ''
    for type in colTypesList:
        if type[0] == label_column_name:
            colType = type[1]
            break
    if colType not in ['INTEGER','integer','double precision','DOUBLE PRECISION','float','FLOAT','boolean','BOOLEAN'] :
        plpy.error("kNN Error: " + \
                    "Data type '{0}' is not a valid type for column '{1}' in table '{2}'.".format(colType, label_column_name, point_source))

    colTypesTestList = get_cols_and_types(test_source)
    colType = ''
    for type in colTypesTestList:
        if type[0] == id_column_name:
            colType = type[1]
            break
    if colType not in ['INTEGER','integer'] :
        plpy.error("kNN Error: " + \
                    "Data type '{0}' is not a valid type for column '{1}' in table '{2}'.".format(colType, id_column_name, test_source))
    return k

# ----------------------------------------------------------------------
m4_changequote(<!`!>, <!'!>)