zhengruifeng commented on code in PR #48105:
URL: https://github.com/apache/spark/pull/48105#discussion_r1758649967
##########
python/pyspark/pandas/plot/core.py:
##########
@@ -68,19 +68,52 @@ class SampledPlotBase:
def get_sampled(self, data):
from pyspark.pandas import DataFrame, Series
+ if not isinstance(data, (DataFrame, Series)):
+ raise TypeError("Only DataFrame and Series are supported for
plotting.")
+ if isinstance(data, Series):
+ data = data.to_frame()
+
fraction = get_option("plotting.sample_ratio")
- if fraction is None:
- fraction = 1 / (len(data) / get_option("plotting.max_rows"))
- fraction = min(1.0, fraction)
- self.fraction = fraction
-
- if isinstance(data, (DataFrame, Series)):
- if isinstance(data, Series):
- data = data.to_frame()
+ if fraction is not None:
+ self.fraction = fraction
sampled =
data._internal.resolved_copy.spark_frame.sample(fraction=self.fraction)
return DataFrame(data._internal.with_new_sdf(sampled))._to_pandas()
else:
- raise TypeError("Only DataFrame and Series are supported for
plotting.")
+ from pyspark.sql import Observation
+
+ max_rows = get_option("plotting.max_rows")
+ observation = Observation("ps plotting")
+ sdf = data._internal.resolved_copy.spark_frame.observe(
+ observation, F.count(F.lit(1)).alias("count")
+ )
+
+ rand_col_name = "__ps_plotting_sampled_plot_base_rand__"
+ id_col_name = "__ps_plotting_sampled_plot_base_id__"
+
+ sampled = (
+ sdf.select(
+ "*",
+ F.rand().alias(rand_col_name),
+ F.monotonically_increasing_id().alias(id_col_name),
+ )
+ .sort(rand_col_name)
+ .limit(max_rows + 1)
Review Comment:
`sort` + `limit` is likely be optimized to `TakeOrderedAndProject` which
output single partition, this `coalesce` here is just used to guarantee the
partitioning.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
