omdSqrtNode

Represents a square root node in the mathematical expression tree. It handles the rendering of the radical symbol (√) and the expression under the root (radicand), ensuring correct visual layout and mathematical behavior.

Class Definition

export class omdSqrtNode extends omdNode

Constructor

`new omdSqrtNode(astNodeData)`

Creates a new omdSqrtNode instance.

astNodeData (object): The math.js AST node containing square root function information. It should have an args property, which is an array containing a single AST node for the radicand. The constructor also initializes the visual radicalPath and radicalLine elements.

Static Methods

`fromString(expressionString)`

Creates an omdSqrtNode from a string representation of a square root function. Requires window.math (math.js) to be available globally for parsing.

expressionString (string): The square root expression as a string (e.g., "sqrt(x+1)").
Returns: omdSqrtNode - A new instance.
Throws: Error if math.js is not available, if the string cannot be parsed, or if it does not represent a valid sqrt function.

Public Properties

argument (omdNode): The node representing the radicand (the expression under the root).
value (string): Always "sqrt" for this node type.
radicalPath (jsvgPath): The SVG path element that draws the radical symbol (√).
radicalLine (jsvgLine): The SVG line element that draws the horizontal line above the radicand.
args (Array<object>): The raw AST arguments passed to the constructor.

Public Methods

`computeDimensions()`

Calculates the dimensions of the square root node. It scales down the font size of the argument, computes its dimensions, and then determines the overall width (radical width + spacing + argument width) and height (argument height + extra height for the radical top).

Overrides: omdNode.computeDimensions().

`updateLayout()`

Updates the layout of the square root node. It positions the argument node, then draws and positions the radicalPath and radicalLine elements relative to the argument, ensuring the radical symbol correctly encloses the radicand.

Overrides: omdNode.updateLayout().

`clone()`

Creates a deep, structural clone of the square root node, including its argument node and visual elements. The cloned node's provenance array is updated to include the original node's ID.

Returns: omdSqrtNode - A new, identical instance of the square root node.

`highlightAll()`

Applies a highlight to the square root node itself and recursively highlights its argument node.

`unhighlightAll()`

Removes the highlight from the square root node and recursively unhighlights its argument node.

`toMathJSNode()`

Converts the omdSqrtNode back into its math.js AST representation. It creates a FunctionNode with fn: 'sqrt' and the converted argument AST.

Returns: object - A math.js FunctionNode for the square root operation. The returned object also includes a clone method for compatibility.

`toString()`

Converts the square root node to its string representation (e.g., "sqrt(x+1)").

Returns: string.

`evaluate(variables)`

Evaluates the square root expression. It evaluates the argument and then calculates its square root.

variables (object): A map of variable names to their numeric values.
Returns: number - The evaluated square root, or NaN if the radicand cannot be evaluated or is negative.

`isSquareRoot()`

Checks if the node represents a square root. Always returns true for omdSqrtNode.

Returns: boolean.

`isCubeRoot()`

Checks if the node represents a cube root. Always returns false for omdSqrtNode.

Returns: boolean.

`toPowerForm()`

Converts the square root node into an equivalent omdPowerNode representation (e.g., sqrt(x) becomes x^(0.5)).

Returns: omdPowerNode - The equivalent power expression, or null if the argument is missing.

Internal Methods

parseValue(): Sets the value property to "sqrt".
createArgumentNode(): Creates an omdNode instance for the radicand from its AST, and adds it as a child.
createRadicalElements(): Creates and initializes the jsvgPath for the radical symbol and the jsvgLine for the horizontal bar, adding them as children.

Example

import { omdSqrtNode } from '@teachinglab/omd';
import * as math from 'mathjs';

// Create from AST
const node = new omdSqrtNode({
  type: 'FunctionNode',
  fn: { name: 'sqrt' },
  args: [ { type: 'SymbolNode', name: 'x' } ]
});

// Or from string
const node2 = omdSqrtNode.fromString('sqrt(x+1)');

// Render and layout
node.setFontSize(24);
node.initialize();

// Evaluate
const val = node.evaluate({ x: 9 }); // 3

// Convert to power form
const powerNode = node.toPowerForm(); // x^(1/2)

// Add to an SVG container to display
// const svgContainer = new jsvgContainer();
// svgContainer.addChild(node);
// document.body.appendChild(svgContainer.svgObject);

OMD Documentation