---
title: Series mapping
description: Assign query columns to chart channels — X axis, Y axis, color, size, and tooltips.
---

Series mapping controls which query columns are assigned to which chart channels. This is done in the **Fields** tab of the chart configuration panel.

{/* TODO screenshot: Fields tab open showing drag targets for X, Y, Color, Size, Tooltip (hidden — replace this comment with <Frame><img src="..." /></Frame> when image is ready) */}

## Chart channels

| Channel | Description | Applicable chart types |
|---|---|---|
| **X** | The horizontal axis dimension or time field | Bar, line, area, scatter, heatmap, boxplot |
| **Y** | The vertical axis measure | Bar, line, area, scatter, boxplot |
| **Color** | Creates one series per unique value; controls stacking behavior | All Vega-based types |
| **Size** | Scales point radius by a numeric measure | Scatter, map |
| **Split by** | Repeats the chart once per unique value, as a grid of panels — see [small multiples](/docs/explore-analyze/charts/configuration/small-multiples) | Bar, line, area, scatter |
| **Tooltip** | Fields shown on hover | All types |
| **Theta** (pie) | The measure that determines slice size | Pie |

## Assigning fields

Drag a field from the **Available fields** list at the bottom of the Fields tab into the target channel slot. You can also drag an already-assigned field between channels.

Fields can appear in more than one channel simultaneously — drag from **Available fields** to add a field to a second channel without removing it from the first. For example, you can assign the same dimension to both the X axis and the tooltip.

{/* TODO screenshot: dragging a field from available fields into the Color channel (hidden — replace this comment with <Frame><img src="..." /></Frame> when image is ready) */}

## Multiple measures on Y

To plot multiple measures as separate series, drag additional measures into the **Y** channel. Each measure renders as its own series, with independent color and style settings in [series configuration](/docs/explore-analyze/charts/configuration/series-configuration).

## Removing a field

Drag a field out of its channel slot back to **Available fields**, or click the **×** on the field token to remove it.
