ClickHouse/docs/en/sql-reference/aggregate-functions/reference/sparkbar.md
2022-08-28 10:53:34 -04:00

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/en/sql-reference/aggregate-functions/reference/sparkbar 311 sparkbar

sparkbar

The function plots a frequency histogram for values x and the repetition rate y of these values over the interval [min_x, max_x].

If no interval is specified, then the minimum x is used as the interval start, and the maximum x — as the interval end.

Syntax

sparkbar(width[, min_x, max_x])(x, y)

Parameters

  • width — The number of segments. Type: Integer.
  • min_x — The interval start. Optional parameter.
  • max_x — The interval end. Optional parameter.

Arguments

  • x — The field with values.
  • y — The field with the frequency of values.

Returned value

  • The frequency histogram.

Example

Query:

CREATE TABLE spark_bar_data (`cnt` UInt64,`event_date` Date) ENGINE = MergeTree ORDER BY event_date SETTINGS index_granularity = 8192;
 
INSERT INTO spark_bar_data VALUES(1,'2020-01-01'),(4,'2020-01-02'),(5,'2020-01-03'),(2,'2020-01-04'),(3,'2020-01-05'),(7,'2020-01-06'),(6,'2020-01-07'),(8,'2020-01-08'),(2,'2020-01-11');

SELECT sparkbar(9)(event_date,cnt) FROM spark_bar_data;

SELECT sparkbar(9,toDate('2020-01-01'),toDate('2020-01-10'))(event_date,cnt) FROM spark_bar_data;

Result:


┌─sparkbar(9)(event_date, cnt)─┐
│                              │
│ ▁▅▄▃██▅ ▁                   │
│                              │
└──────────────────────────────┘

┌─sparkbar(9, toDate('2020-01-01'), toDate('2020-01-10'))(event_date, cnt)─┐
│                                                                          │
│▁▄▄▂▅▇█▁                                                                 │
│                                                                          │
└──────────────────────────────────────────────────────────────────────────┘