--- title: "Violin" description: "Density per category. What the violin is for, the data it needs and every option it has." section: "Widgets" canonical: "https://banksync.io/docs/widgets/chart-violin" specs: ["dashboards"] operationBindings: [{"capability":"dashboards","operation":"dashboards.author"}] --- Density per category. It sits in the **Distribution** group of the widget library. ![Example violin on a BankSync dashboard](https://cdn.banksync.io/screenshots/docs/charts/violin.cd82340e9b82b0d8.png) ## When to use it Use a violin to compare the shape of amounts across groups: where values bunch up, and whether a group has two clusters. Each violin is a smoothed outline of one group's values, with a small box and median dot inside. For example, compare card purchase sizes by merchant category to spot a category with many small purchases and a few large ones. ## When to pick something else - Your readers want medians and ranges they can read at a glance? Use a **Box plot**. - Only a handful of values per group? A **Strip plot** or **Beeswarm** shows each one honestly. - Many groups stacked in a tall card? Try a **Ridgeline**. ## The data it needs Pick these in the **Data** tab of the inspector. BankSync suggests a column for each when your source has an obvious match. | Field | Needed | Pick | Notes | | ------------ | -------- | ---------- | ----- | | **Category** | Optional | a category | | | **Value** | Yes | a number | | | **Series** | Optional | a category | | Each row is drawn as it is, so shape the rows first if you need totals. See [Shaping data](/docs/dashboards/dashboards-shaping-data). ## Violin options Set these on the **Style** tab of the inspector. "Automatic" means BankSync picks a value from the chart's size and data. | Option | What it does | Values | New charts start with | | ------------------- | --------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------- | --------------------- | | **Smoothing** | How much the shape is smoothed, in the units of the data. Larger values give a smoother outline; leave empty for automatic. | Number, 0 or more | Automatic | | **Show box** | Draw a slim box plot inside each violin. On by default. | On or off | Automatic | | **Show median** | Mark the median of each group. On by default. | On or off | Automatic | | **Smoothing shape** | The curve used to smooth the values into a shape. Gaussian is the smoothest; the others give sharper edges. | Gaussian, Epanechnikov, Uniform, Triangular | Automatic | ### Needs history Show a note instead of the chart until the rows cover enough periods, so a first week never reads as a trend. | Option | What it does | Values | New charts start with | | ------------------- | ---------------------------------------------------------------------------------- | ------------------------------- | --------------------- | | **Date field** | The date column whose distinct periods are counted. | Text | Automatic | | **Period** | What counts as one period: a day, week, month, quarter or year. | Day, Week, Month, Quarter, Year | Automatic | | **Periods needed** | How many distinct periods the rows must cover before the chart draws (2 to 60). | Whole number, 2 to 60 | Automatic | | **Waiting message** | Shown until there is enough history. Leave empty for a message naming the periods. | Text, up to 120 characters | Automatic | ## Shared chart styling Every chart also has the shared styling options. These apply to this one: - [Legend](/docs/widgets/chart-styling#legend): position, layout and which series show. - [Axes](/docs/widgets/chart-styling#axes): titles, tick labels and number format. - [Grid](/docs/widgets/chart-styling#grid), [title](/docs/widgets/chart-styling#title), [padding](/docs/widgets/chart-styling#padding) and [background](/docs/widgets/chart-styling#background). - [Value labels](/docs/widgets/chart-styling#value-labels) on the marks. - [Categories and labels](/docs/widgets/chart-styling#categories-and-labels): top N with "Other", sort order, readable labels, the handwritten callout. - [Style](/docs/widgets/chart-styling#style): corner radius, line width, opacity and animation. - [Tooltip](/docs/widgets/chart-styling#tooltip) on hover. - Click to filter: clicking a mark can filter the rest of the dashboard. See [Filters and cross-filtering](/docs/dashboards/filters-and-cross-filtering). - [Colours](/docs/widgets/chart-styling#palette): follow the dashboard palette or pick one for this chart. ## Messy data - Blank or non-numeric values are skipped, not treated as zero. With none left you see "No numbers to show". - Each violin covers only its own group's range. A group where every value is the same draws a small lens around that value. - With only a few values per group the outline looks confident but says little. - Groups beyond what the width can hold fold into "Other (n)", keeping the groups with the most values. ## On a phone Full-width on phones, it fits around a dozen violins, but each gets narrow and the shapes flatten. For two or three groups it reads well; beyond that a **Box plot** is clearer on a small screen. ## Related charts - [Scatter plot](/docs/widgets/chart-scatter): Two measures on x/y - [Histogram](/docs/widgets/chart-histogram): Distribution of one measure - [Box plot](/docs/widgets/chart-boxplot): Quartiles with whiskers - [Beeswarm](/docs/widgets/chart-beeswarm): Non-overlapping dot plot - [Density](/docs/widgets/chart-density): Kernel-smoothed distribution - [Ridgeline](/docs/widgets/chart-ridgeline): Stacked distributions - [Strip plot](/docs/widgets/chart-strip): Each value as a tick - [Jitter plot](/docs/widgets/chart-jitter): Scattered dots per category