Symmetronic Scaleogram

Web component for a scaleogram visualization, e.g. for data from a discrete wavelet transform.

Using this component

Script tag

• Put a script tag similar to this <script src='https://unpkg.com/[email protected]/dist/strc-scaleogram.js'></script> in the head of your index.html
• Then you can use the element anywhere in your template, JSX, HTML, etc.

Node Modules

• Run npm install strc-scaleogram --save
• Put a script tag similar to this <script src='node_modules/strc-scaleogram/dist/strc-scaleogram.js'></script> in the head of your index.html
• Then you can use the element anywhere in your template, JSX, HTML, etc.

In a stencil-starter app

• Run npm install strc-scaleogram --save
• Add an import to the npm packages import strc-scaleogram;
• Then you can use the element anywhere in your template, JSX, HTML, etc.

API

Attributes

• data: String of an array of arrays containing the wavelet coefficients.
• invert-scale (optional): Set to true if you want to invert the direction of the color scale set by the scale attribute.
• scale (optional): Color scale as a string. Any valid string of a Chroma.js color scale can be used.

<strc-scaleogram
  data="[
    [3],
    [5, -5],
    [0, 2, -3, 4],
    [-8, 1, 3, -1, 0, 5, -3, -1]
  ]"
  invert-scale="true"
  scale="['#e66101', '#fdb863', '#f7f7f7', '#b2abd2', '#5e3c99']"
/>

Discrete Wavelets is a JavaScript library that already returns the coefficients in an appropriate format. But you need to convert the array to a string using JSON.stringify().

var data = JSON.stringify(
  coeffs.slice(1) // .slice(1) removes the first element, which are the approximation coefficients
);

Styling

You can adjust the style of the scaleogram.

strc-scaleogram {
  /*
   * Height of the visualization.
   */
  --strc-scaleogram-height: 16rem;

  /*
   * Color of the labels.
   */
  --strc-scaleogram-label-color: #000000;
  
  /*
   * Width of the scaleogram's legend.
   * The default value is 8rem.
   * This can be used to align the scaleogram with e.g. a line chart.
   * Set the right margin of a line chart to the same value as the
   * legend width and the x axes should be perfectly aligned.
   */
  --strc-scaleogram-legend-width: 8rem;
}

NPM scripts

• npm install: Install dependencies
• npm start: Build in development mode
• npm run build: Build in production mode
• npm test: Run tests
• npm run test:watch: Run tests in interactive watch mode