asciichart.js

//https://github.com/kroitor/asciichart

// control sequences for coloring

export const black = "\x1b[30m"
export const red = "\x1b[31m"
export const green = "\x1b[32m"
export const yellow = "\x1b[33m"
export const blue = "\x1b[34m"
export const magenta = "\x1b[35m"
export const cyan = "\x1b[36m"
export const lightgray = "\x1b[37m"
export const adefault = "\x1b[39m"
export const darkgray = "\x1b[90m"
export const lightred = "\x1b[91m"
export const lightgreen = "\x1b[92m"
export const lightyellow = "\x1b[93m"
export const lightblue = "\x1b[94m"
export const lightmagenta = "\x1b[95m"
export const lightcyan = "\x1b[96m"
export const white = "\x1b[97m"
export const reset = "\x1b[0m"

export function colored(char, color) {
    // do not color it if color is not specified
    return (color === undefined) ? char : (color + char + reset)
}

export function plot(series, cfg = undefined) {
    // this function takes both one array and array of arrays
    // if an array of numbers is passed it is transformed to
    // an array of exactly one array with numbers
    if (typeof (series[0]) == "number") {
        series = [series]
    }

    cfg = (typeof cfg !== 'undefined') ? cfg : {}

    let min = (typeof cfg.min !== 'undefined') ? cfg.min : series[0][0]
    let max = (typeof cfg.max !== 'undefined') ? cfg.max : series[0][0]

    for (let j = 0; j < series.length; j++) {
        for (let i = 0; i < series[j].length; i++) {
            min = Math.min(min, series[j][i])
            max = Math.max(max, series[j][i])
        }
    }

    let defaultSymbols = ['┼', '┤', '╶', '╴', '─', '╰', '╭', '╮', '╯', '│']
    let range = Math.abs(max - min)
    let offset = (typeof cfg.offset !== 'undefined') ? cfg.offset : 3
    let padding = (typeof cfg.padding !== 'undefined') ? cfg.padding : '           '
    let height = (typeof cfg.height !== 'undefined') ? cfg.height : range
    let colors = (typeof cfg.colors !== 'undefined') ? cfg.colors : []
    let ratio = range !== 0 ? height / range : 1;
    let min2 = Math.round(min * ratio)
    let max2 = Math.round(max * ratio)
    let rows = Math.abs(max2 - min2)
    let width = 0
    for (let i = 0; i < series.length; i++) {
        width = Math.max(width, series[i].length)
    }
    width = width + offset
    let symbols = (typeof cfg.symbols !== 'undefined') ? cfg.symbols : defaultSymbols
    let format = (typeof cfg.format !== 'undefined') ? cfg.format : function (x) {
        return (padding + x.toFixed(2)).slice(-padding.length)
    }

    let result = new Array(rows + 1) // empty space
    for (let i = 0; i <= rows; i++) {
        result[i] = new Array(width)
        for (let j = 0; j < width; j++) {
            result[i][j] = ' '
        }
    }
    for (let y = min2; y <= max2; ++y) { // axis + labels
        let label = format(rows > 0 ? max - (y - min2) * range / rows : y, y - min2)
        result[y - min2][Math.max(offset - label.length, 0)] = label
        result[y - min2][offset - 1] = (y == 0) ? symbols[0] : symbols[1]
    }

    for (let j = 0; j < series.length; j++) {
        let currentColor = colors[j % colors.length]
        let y0 = Math.round(series[j][0] * ratio) - min2
        result[rows - y0][offset - 1] = colored(symbols[0], currentColor) // first value

        for (let x = 0; x < series[j].length - 1; x++) { // plot the line
            let y0 = Math.round(series[j][x + 0] * ratio) - min2
            let y1 = Math.round(series[j][x + 1] * ratio) - min2
            if (y0 == y1) {
                result[rows - y0][x + offset] = colored(symbols[4], currentColor)
            } else {
                result[rows - y1][x + offset] = colored((y0 > y1) ? symbols[5] : symbols[6], currentColor)
                result[rows - y0][x + offset] = colored((y0 > y1) ? symbols[7] : symbols[8], currentColor)
                let from = Math.min(y0, y1)
                let to = Math.max(y0, y1)
                for (let y = from + 1; y < to; y++) {
                    result[rows - y][x + offset] = colored(symbols[9], currentColor)
                }
            }
        }
    }
    return result.map(function (x) { return x.join('') }).join('\n')
}