import { Container } from 'pixi.js';
import { LayerAxis, LayerLegend } from '../layers';
import { D3Selection, LayerInstance, RawRelation, RawTable, RawTableList, ScaleAngle, ScaleBand, ScaleLinear } from '../types';
/**
 * Check if a number can be calculated.
 * @example
 * isRealNumber(1) // true
 * isRealNumber(NaN) // false
 * @returns
 * Is the value a number other than `NaN`.
 */
export declare function isRealNumber(value: unknown): value is number;
/**
 * `IsEqual` method that ignore floating-point arithmetic errors.
 * @remark
 * The minimum precision is `1E-8`.
 * @example
 * isApproximateNumber(1.00000001, 1.00000002) // false
 * isApproximateNumber(1.000000001, 1.000000002) // true
 * @returns
 * If two numbers are equal.
 */
export declare function isApproximateNumber(n1: number, n2: number): boolean;
/**
 * Check if input is svg container.
 * @returns
 * Is the value a d3 selection.
 */
export declare function isSC(selector: unknown): selector is D3Selection;
/**
 * Check if input is canvas container.
 * @returns
 * Is the value a pixi group.
 */
export declare function isCC(selector: unknown): selector is Container;
export declare function isLayerAxis(instance: Maybe<LayerInstance>): instance is LayerAxis;
export declare function isLayerLegend(instance: Maybe<LayerInstance>): instance is LayerLegend;
export declare function isLayerBasemap(instance: Maybe<LayerInstance>): boolean;
export declare function isScaleBand(scale: any): scale is ScaleBand;
export declare function isScaleLinear(scale: any): scale is ScaleLinear;
export declare function isScaleAngle(scale: any): scale is ScaleAngle;
/**
 * Check if input matches a specific data structure.
 * @remark
 * Empty array `[]` will return `false`.
 * @returns
 * Is the input a strictly `RawTableList`.
 */
export declare function isRawTableList(tableList: unknown): tableList is RawTableList;
/**
 * Check if input matches a specific data structure.
 * @returns
 * Is the input a strictly `RawTable`.
 */
export declare function isRawTable(table: unknown): table is RawTable;
/**
 * Check if input matches a specific data structure.
 * @returns
 * Is the input a strictly `RawRelation`.
 */
export declare function isRawRelation(relation: unknown): relation is RawRelation;