fix: Make dx histogram behavior consistent with px

plugins/plotly-express/docs/histogram.md

@@ -47,6 +47,28 @@ hist_3_bins = dx.histogram(setosa, x="SepalLength", nbins=3)
 hist_8_bins = dx.histogram(setosa, x="SepalLength", nbins=8)
 ```
 
+### Bin and aggregate on different columns
+
+If the plot orientation is vertical (`"v"`), the `x` column is binned and the `y` column is aggregated. The operations are flipped if the plot orientation is horizontal.
+
+
+```python order=hist_v,hist_h,hist_avg,iris
+import deephaven.plot.express as dx
+iris = dx.data.iris()
+
+# subset to get specific species
+setosa = iris.where("Species == `setosa`")
+
+# The default orientation is "v" (vertical) and the default aggregation function is "sum"
+hist_v = dx.histogram(setosa, x="SepalLength", y="SepalWidth")
+
+# Control the plot orientation using orientation
+hist_h = dx.histogram(setosa, x="SepalLength", y="SepalWidth", orientation="h")
+
+# Control the aggregation function using histfunc
+hist_avg = dx.histogram(setosa, x="SepalLength", y="SepalWidth", histfunc="avg")
+```
+
 ### Distributions of several groups
 
 Histograms can also be used to compare the distributional properties of different groups of data, though they may be a little harder to read than [box plots](box.md) or [violin plots](violin.md). Pass the name of the grouping column(s) to the `by` argument.

plugins/plotly-express/src/deephaven/plot/express/deephaven_figure/generate.py

@@ -111,8 +111,9 @@
     "current_col",
     "current_var",
     "labels",
-    "hist_val_name",
-    "pivot_vars",
+    "hist_agg_label",
+    "hist_orientation",
+    "stacked_column_names",
     "current_partition",
     "colors",
     "unsafe_update_figure",
@@ -684,7 +685,7 @@ def handle_custom_args(
     return trace_generator
 
 
-def get_list_var_info(data_cols: Mapping[str, str | list[str]]) -> set[str]:
+def get_list_param_info(data_cols: Mapping[str, str | list[str]]) -> set[str]:
     """Extract the variable that is a list.
 
     Args:
@@ -824,7 +825,8 @@ def hover_text_generator(
 
 def compute_labels(
     hover_mapping: list[dict[str, str]],
-    hist_val_name: str | None,
+    hist_agg_label: str | None,
+    hist_orientation: str | None,
     heatmap_agg_label: str | None,
     # hover_data - todo, dependent on arrays supported in data mappings
     types: set[str],
@@ -837,7 +839,8 @@ def compute_labels(
 
     Args:
       hover_mapping: The mapping of variables to columns
-      hist_val_name: The histogram name for the value axis, generally histfunc
+      hist_agg_label: The histogram agg label
+      hist_orientation: The histogram orientation
       heatmap_agg_label: The aggregate density heatmap column title
       types: Any types of this chart that require special processing
       labels: A dictionary of old column name to new column name mappings
@@ -847,7 +850,7 @@ def compute_labels(
         the renamed current_col
     """
 
-    calculate_hist_labels(hist_val_name, hover_mapping[0])
+    calculate_hist_labels(hist_agg_label, hist_orientation, hover_mapping[0])
 
     calculate_density_heatmap_labels(heatmap_agg_label, hover_mapping[0], labels)
 
@@ -880,27 +883,30 @@ def calculate_density_heatmap_labels(
 
 
 def calculate_hist_labels(
-    hist_val_name: str | None, current_mapping: dict[str, str]
+    hist_agg_label: str | None,
+    hist_orientation: str | None,
+    hover_mapping: dict[str, str],
 ) -> None:
     """Calculate the histogram labels
 
     Args:
-      hist_val_name: The histogram name for the value axis, generally histfunc
-      current_mapping: The mapping of variables to columns
+      hist_agg_label: The histogram agg label
+      hist_orientation: The histogram orientation
+      hover_mapping: The mapping of variables to columns
 
     """
-    if hist_val_name:
-        # swap the names
-        current_mapping["x"], current_mapping["y"] = (
-            current_mapping["y"],
-            current_mapping["x"],
-        )
+    # only one should be set
+    if hist_orientation == "h" and hist_agg_label:
+        # a bar chart oriented horizontally has the histfunc on the x-axis
+        hover_mapping["x"] = hist_agg_label
+    elif hist_orientation == "v" and hist_agg_label:
+        hover_mapping["y"] = hist_agg_label
 
 
 def add_axis_titles(
     custom_call_args: dict[str, Any],
     hover_mapping: list[dict[str, str]],
-    hist_val_name: str | None,
+    hist_agg_label: str | None,
     heatmap_agg_label: str | None,
 ) -> None:
     """Add axis titles. Generally, this only applies when there is a list variable
@@ -909,7 +915,7 @@ def add_axis_titles(
       custom_call_args: The custom_call_args that are used to
         create hover and axis titles
       hover_mapping: The mapping of variables to columns
-      hist_val_name: The histogram name for the value axis, generally histfunc
+      hist_agg_label: The histogram agg label
       heatmap_agg_label: The aggregate density heatmap column title
 
     """
@@ -919,8 +925,8 @@ def add_axis_titles(
     new_xaxis_titles = None
     new_yaxis_titles = None
 
-    if hist_val_name:
-        # hist names are already set up in the mapping
+    if hist_agg_label:
+        # hist labels are already set up in the mapping
         new_xaxis_titles = [hover_mapping[0].get("x", None)]
         new_yaxis_titles = [hover_mapping[0].get("y", None)]
 
@@ -945,7 +951,7 @@ def create_hover_and_axis_titles(
     hover_mapping: list[dict[str, str]],
 ) -> Generator[dict[str, Any], None, None]:
     """Create hover text and axis titles. There are three main behaviors.
-    First is "current_col", "current_var", and "pivot_vars" are specified in
+    First is "current_col", "current_var", and "stacked_column_names" are specified in
     "custom_call_args".
     In this case, there is a list of variables, but they are layered outside
     the generate function.
@@ -975,17 +981,19 @@ def create_hover_and_axis_titles(
     Yields:
       Dicts containing hover updates
     """
-    types = get_list_var_info(data_cols)
+    types = get_list_param_info(data_cols)
 
     labels = custom_call_args.get("labels", None)
-    hist_val_name = custom_call_args.get("hist_val_name", None)
+    hist_agg_label = custom_call_args.get("hist_agg_label", None)
+    hist_orientation = custom_call_args.get("hist_orientation", None)
     heatmap_agg_label = custom_call_args.get("heatmap_agg_label", None)
 
     current_partition = custom_call_args.get("current_partition", {})
 
     compute_labels(
         hover_mapping,
-        hist_val_name,
+        hist_agg_label,
+        hist_orientation,
         heatmap_agg_label,
         types,
         labels,
@@ -998,7 +1006,12 @@ def create_hover_and_axis_titles(
         # it's possible that heatmap_agg_label was relabeled, so grab the new label
         heatmap_agg_label = hover_mapping[0]["z"]
 
-    add_axis_titles(custom_call_args, hover_mapping, hist_val_name, heatmap_agg_label)
+    add_axis_titles(
+        custom_call_args,
+        hover_mapping,
+        hist_agg_label,
+        heatmap_agg_label,
+    )
 
     return hover_text
 

plugins/plotly-express/src/deephaven/plot/express/plots/PartitionManager.py

@@ -9,7 +9,7 @@
 
 from deephaven.table import Table, PartitionedTable
 from deephaven import pandas as dhpd
-from deephaven import merge, empty_table
+from deephaven import merge
 
 from ._layer import atomic_layer
 from .. import DeephavenFigure
@@ -109,10 +109,10 @@ class PartitionManager:
 
     Attributes:
         by_vars: set[str]: The set of by_vars that can be used in a plot by
-        list_var: str: "x" or "y" depending on which var is a list
-        cols: str | list: The columns set by the list_var
-        pivot_vars: dict[str, str]: A dictionary that stores the "real" column
-          names if there is a list_var. This is needed in case the column names
+        list_param: str: "x" or "y" depending on which param is a list
+        cols: str | list: The columns set by the list_param
+        stacked_column_names: dict[str, str]: A dictionary that stores the "real" column
+          names if there is a list_param. This is needed in case the column names
           used are already in the table.
         has_color: bool: True if this figure has user set color, False otherwise
         facet_row: str: The facet row
@@ -146,9 +146,9 @@ def __init__(
     ):
         self.by = None
         self.by_vars = None
-        self.list_var = None
+        self.list_param = None
         self.cols = None
-        self.pivot_vars = {}
+        self.stacked_column_names = {}
         self.has_color = None
         self.facet_row = None
         self.facet_col = None
@@ -199,13 +199,13 @@ def set_long_mode_variables(self) -> None:
             self.groups.discard("supports_lists")
             return
 
-        self.list_var = var
+        self.list_param = var
         self.cols = cols
 
-        args["current_var"] = self.list_var
+        args["current_var"] = self.list_param
 
-        self.pivot_vars = get_unique_names(table, ["variable", "value"])
-        self.args["pivot_vars"] = self.pivot_vars
+        self.stacked_column_names = get_unique_names(table, ["variable", "value"])
+        self.args["stacked_column_names"] = self.stacked_column_names
 
     def convert_table_to_long_mode(
         self,
@@ -227,7 +227,7 @@ def convert_table_to_long_mode(
 
         # if there is no plot by arg, the variable column becomes it
         if not self.args.get("by", None):
-            args["by"] = self.pivot_vars["variable"]
+            args["by"] = self.stacked_column_names["variable"]
 
         args["table"] = self.to_long_mode(table, self.cols)
 
@@ -418,7 +418,11 @@ def process_partitions(self) -> Table | PartitionedTable:
 
         # preprocessor needs to be initialized after the always attached arguments are found
         self.preprocessor = Preprocessor(
-            args, self.groups, self.always_attached, self.pivot_vars
+            args,
+            self.groups,
+            self.always_attached,
+            self.stacked_column_names,
+            self.list_param,
         )
 
         if partition_cols:
@@ -468,12 +472,14 @@ def build_ternary_chain(self, cols: list[str]) -> str:
         Returns:
             The ternary string that builds the new column
         """
-        ternary_string = f"{self.pivot_vars['value']} = "
+        ternary_string = f"{self.stacked_column_names['value']} = "
         for i, col in enumerate(cols):
             if i == len(cols) - 1:
                 ternary_string += f"{col}"
             else:
-                ternary_string += f"{self.pivot_vars['variable']} == `{col}` ? {col} : "
+                ternary_string += (
+                    f"{self.stacked_column_names['variable']} == `{col}` ? {col} : "
+                )
         return ternary_string
 
     def to_long_mode(self, table: Table, cols: list[str] | None) -> Table:
@@ -494,7 +500,7 @@ def to_long_mode(self, table: Table, cols: list[str] | None) -> Table:
         new_tables = []
         for col in cols:
             new_tables.append(
-                table.update_view(f"{self.pivot_vars['variable']} = `{col}`")
+                table.update_view(f"{self.stacked_column_names['variable']} = `{col}`")
             )
 
         merged = merge(new_tables)
@@ -545,7 +551,9 @@ def table_partition_generator(
         Yields:
             The tuple of table and current partition
         """
-        column = self.pivot_vars["value"] if self.pivot_vars else None
+        column = (
+            self.stacked_column_names["value"] if self.stacked_column_names else None
+        )
         if self.preprocessor:
             tables = self.preprocessor.preprocess_partitioned_tables(
                 self.constituents, column
@@ -571,9 +579,13 @@ def partition_generator(self) -> Generator[dict[str, Any], None, None]:
                     # if a tuple is returned here, it was preprocessed already so pivots aren't needed
                     table, arg_update = table
                     args.update(arg_update)
-                elif self.pivot_vars and self.pivot_vars["value"] and self.list_var:
+                elif (
+                    self.stacked_column_names
+                    and self.stacked_column_names["value"]
+                    and self.list_param
+                ):
                     # there is a list of variables, so replace them with the combined column
-                    args[self.list_var] = self.pivot_vars["value"]
+                    args[self.list_param] = self.stacked_column_names["value"]
 
                 args["current_partition"] = current_partition
 
@@ -680,8 +692,8 @@ def create_figure(self) -> DeephavenFigure:
             # by color (colors might be used multiple times)
             self.marg_args["table"] = self.partitioned_table
 
-            if self.pivot_vars and self.pivot_vars["value"]:
-                self.marg_args[self.list_var] = self.pivot_vars["value"]
+            if self.stacked_column_names and self.stacked_column_names["value"]:
+                self.marg_args[self.list_param] = self.stacked_column_names["value"]
 
             self.marg_args["color"] = self.marg_color
 

plugins/plotly-express/src/deephaven/plot/express/plots/_private_utils.py

@@ -233,8 +233,12 @@ def create_deephaven_figure(
         # this is a marginal, so provide an empty update function
         update_wrapper = lambda x: x
 
-    list_var = partitioned.list_var
-    pivot_col = partitioned.pivot_vars["value"] if partitioned.pivot_vars else None
+    list_param = partitioned.list_param
+    pivot_col = (
+        partitioned.stacked_column_names["value"]
+        if partitioned.stacked_column_names
+        else None
+    )
     by = partitioned.by
 
     update = {}
@@ -243,9 +247,9 @@ def create_deephaven_figure(
         # by needs to be updated as if there is a list variable but by is None, the pivot column is used as the by
         update["by"] = by
 
-    if list_var:
+    if list_param:
         # if there is a list variable, update the list variable to the pivot column
-        update[list_var] = pivot_col
+        update[list_param] = pivot_col
 
     return (
         update_wrapper(partitioned.create_figure()),
@@ -489,7 +493,6 @@ def shared_histogram(is_marginal: bool = True, **args: Any) -> DeephavenFigure:
     set_all(args, HISTOGRAM_DEFAULTS)
 
     args["bargap"] = 0
-    args["hist_val_name"] = args.get("histfunc", "count")
 
     func = px.bar
     groups = {"bar", "preprocess_hist", "supports_lists"}

plugins/plotly-express/src/deephaven/plot/express/plots/bar.py

@@ -10,7 +10,7 @@
 from ._private_utils import validate_common_args, process_args
 from ..shared import default_callback
 from ..deephaven_figure import generate_figure, DeephavenFigure
-from ..types import PartitionableTableLike
+from ..types import PartitionableTableLike, Orientation
 
 
 def bar(
@@ -42,6 +42,7 @@ def bar(
     range_color: list[float] | None = None,
     color_continuous_midpoint: float | None = None,
     opacity: float | None = None,
+    orientation: Orientation | None = None,
     barmode: str = "relative",
     log_x: bool = False,
     log_y: bool = False,
@@ -114,6 +115,12 @@ def bar(
       color_continuous_midpoint: A number that is the midpoint of the color axis
       opacity: Opacity to apply to all markers. 0 is completely transparent
         and 1 is completely opaque.
+      orientation: The orientation of the bars.
+        If 'v', the bars are vertical.
+        If 'h', the bars are horizontal.
+        Defaults to 'v' if only `x` is specified.
+        Defaults to 'h' if only `y` is specified.
+        Defaults to 'v' if both `x` and `y` are specified unless `x` is passed only numeric columns and `y` is not.
       barmode: If 'relative', bars are stacked. If 'overlay', bars are drawn on top
         of each other. If 'group', bars are drawn next to each other.
       log_x: A boolean or list of booleans that specify if