Creating Charts

In contrast to existing chart creation tools, Charticulator allows you to interactively specify a chart’s layout. It automatically places glyphs based on your layout specification. Like other chart creation tools, Charticulator allows you to interactively style individual chart elements such as size, color, font, etc. In this tutorial, we describe the set of interactions used to create a chart in Charticulator. To see more examples of chart creation with Charticulator, refer to the creation process videos in the gallery as well as our video tutorials.

On this page, clicking a button below will reveal the corresponding tutorial.

Interaction

Adding a Mark (to a Glyph)

Charticulator supports five types of marks: a Shape, a Symbol, a Line, a Text, and an Image. To add a mark to a glyph, you can drag the desired mark from the Toolbar and drop it into the Glyph Editor. Charticulator places the new mark at its default position: the center of the glyph. Charticulator also adds a corresponding entry to the Layers Panel. ( )

Charticulator now supports three types of shapes: rectangle, oval, and triangle. You can change the shape type from the Attributes Panel. ( )

To place the mark at a specific location, you can click the mark to activate it and click or drag within the Glyph Editor, depending on the mark type. ( )

Guides can be added to a glyph from the Toolbar via the same interaction. ( )

Changing a Symbol

Charticulator supports seven types of symbols: a circle, a cross, a diamond, a square, a star, a triangle, and a wye. You can change the symbol type after you added the symbol mark to the Glyph Editor.

Binding Data

You can drag a data column from the Dataset Panel and drop it into dropzones in the Glyph Editor, the Chart Canvas, or the Attributes Panel. The compatible dropzones will appear (highlighed in blue) once you start dragging a data column. ( )

You can also select the data column from data binding popup panels in the Attributes Panel. ( )

Specifying Constraints

You can specify the layout relationship between two objects using anchors and/or handles. For example, you can snap elements to the guides, such as the default guides in the Glyph Editor and Chart Canvas. ( ) For instance, you can ensure the same gap between a text mark and a rectangle in the Glyph Editor by dragging the anchor of the text to the top of the rectangle. Similarly, you can drag a gap handle to adjust the gaps between glyphs in the Chart Canvas. ( )

Creaing a Guide

You can create your own guides to facilitate the alignment of elements. To create a guide, click the desired guide (horizontal or vertical) in the Toolbar to activate it; subsequently clicking on the Glyph Editor or Chart Canvas will add the new guide.

Creating Links

To create a link between glyphs, you must specify the shape (i.e., line or band) and connection method from the corresponding panel in the Toolbar. ( )

You can adjust the anchor positions of links directly from the Chart Canvas. ( )

Configuring Scales

For attributes that are bound to data, Charticulator uses a scale to determine how the data is mapped to visual properties. Scales have their own attributes, and you can edit their attributes by toggling a scales panel from the Attributes Panel. ( )

For the image field of the image mark, you can assign an image for each unique data value.

Adding a Legend

Legends visualize the scales used in a chart. Charticulator currently uses a predefined legend for each scale type. You can add a lenged to the chart by clicking on the “Add Legend” button from a scales panel. ( )

Data-Driven Visibility

Charticulator also supports data-driven visibility, where the visibility of marks is determined by data values. Clicking on the “Conditioned by” button in the Visibility attribute invokes a popup panel, where you can set a filter. For categorical variables, you can set a filter via a set of checkboxes. ( )

For numberical variables, you can specify a simple boolean query (e.g., Count > 0).

Axis Sort

Charticualtor allows you to chanage the order of the X and Y axes labels. You can manually reorder them with a drag-and-drop interaction. You can also reverse the current order of the labels.

Layout Composition

By default, a chart begins with a rectangular plot segment and a Cartesian coordinate system. A plot segment has two independent layout directions, each of which can be assigned as a scaffold, a categorical axis, or a numerical axis.

• A scaffold stacks glyphs sequentially within the plot segment
• A categorical axis groups glyphs according to a categorical attribute, grouping them evenly along the axis ( )
• A numerical axis positions glyphs according to their numerical values ( )

The diagram below shows the possible layouts produced from combining scaffolds and axes.

Sub-layouts

For categorical axes, Charticulator employs sub-layouts to determine a within-group layout. Charticulator currently supports four types of sub-layouts: horizontal stacking, vertical stacking, grid, and circle-packing. ( )

Coordinate Systems

Charticulator suppors three coordinate systems: Cartesian, Polar, and Custom curve. Charticulator morphs mark shapes in the two non-Cartesian systems, and its morphing maintains a precise data binding because the morphing is performed in vector graphics. For example, a rectangle becomes a wedge shape in a polor coordinate system and a custom curve coordinate system. ( )

Data-Driven Guides

A data-driven guide provides data-driven anchor points from data columns sharing the same numerical unit (e.g., min and max temperature values). A Data-driven guide can be displayed as an axis, though to avoid duplicated axes, Charticulator shows only the first instance. To learn more about data-driven guides, please refer to the work of Kim et al (2016). ( )

Glyph elements can be snapped to these anchor points by adding layout constraints (e.g., placing the circle mark at the anchor point of the “Avg. Temperature” data column). ( )

Text Formatting

Charticulator provides simple formatting for the text attribute. When the column name does not contain spaces or special characters, you can refer to a data column using the column name (e.g., Share, Temperature); otherwise, you need to enclose the column name with the grave symbol (`) (e.g., `Import Value`, `Avg. Temperature`). Note that the expression is case sensitive.

Charticulator allows you to format the value of an expression with a format specifier, which follows d3’s syntax. For example, when you bind a numerical variable (called Mean) to the text attribute of a text mark, the default text string is “${avg(Mean)}{.1f}”, where {.1f} indicates one number is shown past the decimal point. ( ) When Group by is applied, the data rows come as a list and thus it is necessary to use an aggregation function even if there is only one data row in each group. Charticulator, by default, uses an avg aggregation function in all cases.

Charticulator allows you to use simple arithmetic the expression. For example, if you want to convert the Temperature value from Celsius to Fahrenheit, you can change the text string to “${avg(Temperature) * 1.8 + 32}”.

You can combine multiple columns to produce a single text string. Keep in mind that data rows come as a list, so it is necessary to use an aggregation function even if there is only one row. To compute the sum of the two columns, you can use the “${avg(`Import Value` + `Export Value`)” text string.

You can also combine data values with a regular string. For example, if you want to add a percentage sign (%) after the Share value, you can change the text string to “${avg(Share)}{.1f}%”. The dollar symbol ($) is reserved to specify the expression. Therefore, if you want to include a dollar sign to the string, you need to preprend the backslash symbol (\). For example, to prepend a dollar sign before the Price value with two numbers after the decimal point, the text string should be “\$${avg(Price)}{.2f}”.

Charticulator currently support two constants—E (=2.718281828…) and PI (=3.1415926…)—as well as common math functions including floor, ceil, exp, log, sin, cos, tan, sqrt, and pow. In addition, it supports common aggregation functions such as min, max, sum, avg, stdev, variance, median, and count. It also allows you to retrive the first and last value with the first and last fuction, respectively.