Add axis types as chart operator flags (#4157)

Relevant for tenzir/issues#1256.

changelog/next/features/4147-chart-axis-type.md

@@ -0,0 +1,4 @@
+The chart operator now accepts the flags `--x-axis-type` and `--y-axis-type`
+for `bar`, `line`, and `area` charts, with the possible values being `log` and
+`linear`, with `linear` as the default value. Setting these flags defines the
+scale (logarithmic or linear) on the Tenzir App chart visualization.

libtenzir/builtins/operators/chart.cpp

@@ -724,10 +724,14 @@ chart_definition chart_definitions[] = {
       {.attr = "x", .flag = "-x,--x-axis", .type = flag_type::field_name, .default_ = nth_field{0}, .allow_lists = false, .req = requirement::strictly_increasing,},
       {.attr = "y", .flag = "-y,--y-axis", .type = flag_type::field_name, .default_ = nth_field{1, nth_field::all_the_rest}, .allow_lists = true,},
       {.attr = "position", .flag = "--position", .type = flag_type::attribute_value, .default_ = attribute_value{"grouped"}, .allow_lists = false,},
+      {.attr = "x_axis_type", .flag = "--x-axis-type", .type = flag_type::attribute_value, .default_ = attribute_value{"linear"}, .allow_lists = false,},
+      {.attr = "y_axis_type", .flag = "--y-axis-type", .type = flag_type::attribute_value, .default_ = attribute_value{"linear"}, .allow_lists = false,},
     },
     .verifications = {
       disallow_mixmatch_between_explicit_and_implicit_arguments({"x", "y"}),
       require_attribute_value_one_of("position", {"grouped", "stacked"}),
+      require_attribute_value_one_of("x_axis_type", {"log", "linear"}),
+      require_attribute_value_one_of("y_axis_type", {"log", "linear"}),
     },
   },
   // `area` is equivalent to `line`.
@@ -738,10 +742,14 @@ chart_definition chart_definitions[] = {
       {.attr = "x", .flag = "-x,--x-axis", .type = flag_type::field_name, .default_ = nth_field{0}, .allow_lists = false, .req = requirement::strictly_increasing,},
       {.attr = "y", .flag = "-y,--y-axis", .type = flag_type::field_name, .default_ = nth_field{1, nth_field::all_the_rest}, .allow_lists = true,},
       {.attr = "position", .flag = "--position", .type = flag_type::attribute_value, .default_ = attribute_value{"grouped"}, .allow_lists = false,},
+      {.attr = "x_axis_type", .flag = "--x-axis-type", .type = flag_type::attribute_value, .default_ = attribute_value{"linear"}, .allow_lists = false,},
+      {.attr = "y_axis_type", .flag = "--y-axis-type", .type = flag_type::attribute_value, .default_ = attribute_value{"linear"}, .allow_lists = false,},
     },
     .verifications = {
       disallow_mixmatch_between_explicit_and_implicit_arguments({"x", "y"}),
       require_attribute_value_one_of("position", {"grouped", "stacked"}),
+      require_attribute_value_one_of("x_axis_type", {"log", "linear"}),
+      require_attribute_value_one_of("y_axis_type", {"log", "linear"}),
     },
   },
   // `bar` is equivalent to `line`, except the requirement on `x` is for the values to be unique.
@@ -752,10 +760,14 @@ chart_definition chart_definitions[] = {
       {.attr = "x", .flag = "-x,--x-axis", .type = flag_type::field_name, .default_ = nth_field{0}, .allow_lists = false, .req = requirement::unique,},
       {.attr = "y", .flag = "-y,--y-axis", .type = flag_type::field_name, .default_ = nth_field{1, nth_field::all_the_rest}, .allow_lists = true,},
       {.attr = "position", .flag = "--position", .type = flag_type::attribute_value, .default_ = attribute_value{"grouped"}, .allow_lists = false,},
+      {.attr = "x_axis_type", .flag = "--x-axis-type", .type = flag_type::attribute_value, .default_ = attribute_value{"linear"}, .allow_lists = false,},
+      {.attr = "y_axis_type", .flag = "--y-axis-type", .type = flag_type::attribute_value, .default_ = attribute_value{"linear"}, .allow_lists = false,},
     },
     .verifications = {
       disallow_mixmatch_between_explicit_and_implicit_arguments({"x", "y"}),
       require_attribute_value_one_of("position", {"grouped", "stacked"}),
+      require_attribute_value_one_of("x_axis_type", {"log", "linear"}),
+      require_attribute_value_one_of("y_axis_type", {"log", "linear"}),
     },
   },
   // `pie` chart is equivalent to `line` and `bar`, except

tenzir/integration/data/reference/pipelines_local/test_chart_arguments/step_04.ref

@@ -1,3 +1,3 @@
 error: failed to infer fields to use for charting
  = hint: either specify `x` and `y` as arguments explicitly, or none of them, and utilize the `select` operator
- = usage: chart bar [-x|--x-axis <field>] [--position <position>] [-y|--y-axis <fields>]
+ = usage: chart bar [-x|--x-axis <field>] [--position <position>] [--x-axis-type <x_axis_type>] [--y-axis-type <y_axis_type>] [-y|--y-axis <fields>]

tenzir/integration/data/reference/vast/test_bar_chart/step_01.ref

@@ -1 +1 @@
-{"chart": "bar", "position": "grouped", "x": "id.orig_h", "y": "count"}
+{"chart": "bar", "position": "grouped", "x": "id.orig_h", "x_axis_type": "linear", "y": "count", "y_axis_type": "linear"}

tenzir/integration/data/reference/vast/test_bar_chart/step_03.ref

@@ -1 +1 @@
-{"chart": "bar", "position": "grouped", "x": "id.orig_h", "y": "count"}
+{"chart": "bar", "position": "grouped", "x": "id.orig_h", "x_axis_type": "linear", "y": "count", "y_axis_type": "linear"}

tenzir/integration/data/reference/vast/test_line_chart/step_01.ref

@@ -1 +1 @@
-{"chart": "line", "position": "grouped", "x": "ts", "y": "orig_bytes"}
+{"chart": "line", "position": "grouped", "x": "ts", "x_axis_type": "linear", "y": "orig_bytes", "y_axis_type": "linear"}

tenzir/integration/data/reference/vast/test_line_chart/step_03.ref

@@ -1 +1 @@
-{"chart": "line", "position": "grouped", "x": "ts", "y": "orig_bytes"}
+{"chart": "line", "position": "grouped", "x": "ts", "x_axis_type": "linear", "y": "orig_bytes", "y_axis_type": "linear"}

web/docs/operators/chart.md

@@ -12,8 +12,11 @@ Add metadata to a schema, necessary for rendering as a chart.
 
 ```
 chart line [-x|--x-axis <fields>] [-y|--y-axis <field>]
+           [--x-axis-type <x-axis-type>]  [--y-axis-type <y-axis-type>]
 chart area [-x|--x-axis <fields>] [-y|--y-axis <field>]
+           [--x-axis-type <x-axis-type>]  [--y-axis-type <y-axis-type>]
 chart bar  [-x|--x-axis <fields>] [-y|--y-axis <field>]
+           [--x-axis-type <x-axis-type>]  [--y-axis-type <y-axis-type>]
 chart pie  [--name <field>] [--value <fields>]
 ```
 
@@ -42,13 +45,27 @@ Sets the fields used for the Y-axis.
 
 Defaults to every field but the first one.
 
-### `position=<position>` (`line`, `area`, and `bar` charts only)
+### `--position <position>` (`line`, `area`, and `bar` charts only)
 
 Controls how the values are grouped when rendered as a chart.
 Possible values are `grouped` and `stacked`.
 
 Defaults to `grouped`.
 
+### `--x-axis-type <x-axis-type>` (`line`, `area`, and `bar` charts only)
+
+Sets the x-axis scale type.
+Possible values are `linear` and `log`.
+
+Defaults to `linear`.
+
+### `--y-axis-type <y-axis-type>` (`line`, `area`, and `bar` charts only)
+
+Sets the y-axis scale type.
+Possible values are `linear` and `log`.
+
+Defaults to `linear`.
+
 ### `--name <field>` (`pie` chart only)
 
 Sets the field used for the names of the segments.
@@ -83,5 +100,5 @@ metrics
 | where source == true
 | summarize bytes=sum(output.approx_bytes) by timestamp resolution 1s
 | sort timestamp desc
-| chart line -x timestamp -y bytes
+| chart line -x timestamp -y bytes --y-axis-type "log"
 ```