LogarithmicAxis.js 4.11 KB
/* *
 *
 *  (c) 2010-2019 Torstein Honsi
 *
 *  License: www.highcharts.com/license
 *
 *  !!!!!!! SOURCE GETS TRANSPILED BY TYPESCRIPT. EDIT TS FILE ONLY. !!!!!!!
 *
 * */
'use strict';
import H from './Globals.js';
import './Utilities.js';
var Axis = H.Axis, getMagnitude = H.getMagnitude, normalizeTickInterval = H.normalizeTickInterval, pick = H.pick;
/* ************************************************************************** *
 * Methods defined on the Axis prototype
 * ************************************************************************** */
/* eslint-disable valid-jsdoc */
/**
 * Set the tick positions of a logarithmic axis.
 *
 * @private
 * @function Highcharts.Axis#getLogTickPositions
 * @param {number} interval
 * @param {number} min
 * @param {number} max
 * @param {boolean} [minor]
 * @return {Array<number>}
 */
Axis.prototype.getLogTickPositions = function (interval, min, max, minor) {
    var axis = this, options = axis.options, axisLength = axis.len, 
    // Since we use this method for both major and minor ticks,
    // use a local variable and return the result
    positions = [];
    // Reset
    if (!minor) {
        axis._minorAutoInterval = null;
    }
    // First case: All ticks fall on whole logarithms: 1, 10, 100 etc.
    if (interval >= 0.5) {
        interval = Math.round(interval);
        positions = axis.getLinearTickPositions(interval, min, max);
        // Second case: We need intermediary ticks. For example
        // 1, 2, 4, 6, 8, 10, 20, 40 etc.
    }
    else if (interval >= 0.08) {
        var roundedMin = Math.floor(min), intermediate, i, j, len, pos, lastPos, break2;
        if (interval > 0.3) {
            intermediate = [1, 2, 4];
            // 0.2 equals five minor ticks per 1, 10, 100 etc
        }
        else if (interval > 0.15) {
            intermediate = [1, 2, 4, 6, 8];
        }
        else { // 0.1 equals ten minor ticks per 1, 10, 100 etc
            intermediate = [1, 2, 3, 4, 5, 6, 7, 8, 9];
        }
        for (i = roundedMin; i < max + 1 && !break2; i++) {
            len = intermediate.length;
            for (j = 0; j < len && !break2; j++) {
                pos = axis.log2lin(axis.lin2log(i) * intermediate[j]);
                // #1670, lastPos is #3113
                if (pos > min &&
                    (!minor || lastPos <= max) &&
                    lastPos !== undefined) {
                    positions.push(lastPos);
                }
                if (lastPos > max) {
                    break2 = true;
                }
                lastPos = pos;
            }
        }
        // Third case: We are so deep in between whole logarithmic values that
        // we might as well handle the tick positions like a linear axis. For
        // example 1.01, 1.02, 1.03, 1.04.
    }
    else {
        var realMin = axis.lin2log(min), realMax = axis.lin2log(max), tickIntervalOption = minor ?
            this.getMinorTickInterval() :
            options.tickInterval, filteredTickIntervalOption = tickIntervalOption === 'auto' ?
            null :
            tickIntervalOption, tickPixelIntervalOption = options.tickPixelInterval / (minor ? 5 : 1), totalPixelLength = minor ?
            axisLength / axis.tickPositions.length :
            axisLength;
        interval = pick(filteredTickIntervalOption, axis._minorAutoInterval, (realMax - realMin) *
            tickPixelIntervalOption / (totalPixelLength || 1));
        interval = normalizeTickInterval(interval, null, getMagnitude(interval));
        positions = axis.getLinearTickPositions(interval, realMin, realMax).map(axis.log2lin);
        if (!minor) {
            axis._minorAutoInterval = interval / 5;
        }
    }
    // Set the axis-level tickInterval variable
    if (!minor) {
        axis.tickInterval = interval;
    }
    return positions;
};
/**
 * @private
 * @function Highcharts.Axis#log2lin
 *
 * @param {number} num
 *
 * @return {number}
 */
Axis.prototype.log2lin = function (num) {
    return Math.log(num) / Math.LN10;
};
/**
 * @private
 * @function Highcharts.Axis#lin2log
 *
 * @param {number} num
 *
 * @return {number}
 */
Axis.prototype.lin2log = function (num) {
    return Math.pow(10, num);
};