Section 1.1: Setting Up Your Environment

Before we can start adding TreeMaps, we need to install the necessary packages. To begin, execute the following command:

npm i @visx/group @visx/hierarchy @visx/mock-data @visx/responsive @visx/scale

This command installs the essential modules for our project.

Section 1.2: Implementing the TreeMap

To introduce a TreeMap in our React application, we can use the following code:

import React, { useState } from "react";

import { Group } from "@visx/group";

import {

Treemap,

hierarchy,

stratify,

treemapSquarify,

treemapBinary,

treemapDice,

treemapResquarify,

treemapSlice,

treemapSliceDice

} from "@visx/hierarchy";

import shakespeare from "@visx/mock-data/lib/mocks/shakespeare";

import { scaleLinear } from "@visx/scale";

const color1 = "#f3e9d2";

const color2 = "#4281a4";

const background = "#114b5f";

const colorScale = scaleLinear({

domain: [0, Math.max(...shakespeare.map((d) => d.size || 0))],

range: [color2, color1]

});

const data = stratify()

.id((d) => d.id)

.parentId((d) => d.parent)(shakespeare)

.sum((d) => d.size || 0);

const tileMethods = {

treemapSquarify,

treemapBinary,

treemapDice,

treemapResquarify,

treemapSlice,

treemapSliceDice

};

const defaultMargin = { top: 10, left: 10, right: 10, bottom: 10 };

function Example({ width, height, margin = defaultMargin }) {

const [tileMethod, setTileMethod] = useState("treemapSquarify");

const xMax = width - margin.left - margin.right;

const yMax = height - margin.top - margin.bottom;

const root = hierarchy(data).sort((a, b) => (b.value || 0) - (a.value || 0));

return width < 10 ? null : (

<div>

<label>Tile Method</label>{" "}

<select

onClick={(e) => e.stopPropagation()}

onChange={(e) => setTileMethod(e.target.value)}

value={tileMethod}

>

{Object.keys(tileMethods).map((tile) => (

<option key={tile} value={tile}>

{tile}

</option>

))}

</select>

<div>

<svg width={width} height={height}>

<rect width={width} height={height} rx={14} fill={background} />

<Treemap

top={margin.top}

root={root}

size={[xMax, yMax]}

tile={tileMethods[tileMethod]}

round

>

{(treemap) => (

<Group>

{treemap

.descendants()

.reverse()

.map((node, i) => {

const nodeWidth = node.x1 - node.x0;

const nodeHeight = node.y1 - node.y0;

return (

<Group

key={node-${i}}

top={node.y0 + margin.top}

left={node.x0 + margin.left}

>

{node.depth === 1 && (

<rect

width={nodeWidth}

height={nodeHeight}

stroke={background}

strokeWidth={4}

fill="transparent"

/>

)}

{node.depth > 2 && (

<rect

width={nodeWidth}

height={nodeHeight}

stroke={background}

fill={colorScale(node.value || 0)}

/>

)}

</Group>

);

})}

</Group>

)}

</Treemap>

</svg>

</div>

</div>

);

}

export default function App() {

return (

<div className="App">

<Example width={500} height={300} />

</div>

);

}

In this code snippet, we define colors for the partitions using the color1 and color2 variables. The background variable sets the background color. The colorScale variable generates color variations for the partitions, while the stratify method organizes our data into a usable format for the TreeMap.

Next, within the Example component, we include a dropdown menu to select the tile method for the TreeMap layout. This feature allows users to customize the tile format displayed in the TreeMap. Finally, we render the Treemap component, calling descendants to retrieve the nodes and rendering them in a structured manner based on their depth levels.

In this video, "Data Visualization with D3, React, visx and Typescript: 12 - Creating a Useful Chart with visx," you will learn how to create informative charts using the Visx library alongside D3 and React.

This video, "Getting Started with the React TreeMap Component," provides an introduction to using the TreeMap component in your React applications.