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@jurca
Created January 27, 2023 09:16
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Generator of ASCII-style column graphs
/**
* Generates an ASCII-style (using UTF-8 characters) column graph of the provided values.
*
* @param {number[]} data The values to graph as columns. Each value will be represented by a single column in the graph.
* @param {number} minY The lower bound of the Y axis.
* @param {number} maxY The upper bound of the Y axis.
* @param {number} scaleY The number of text rows to represent the Y axis.
* @return {string} Generated text-based column graph.
*/
function asciiGraph(data, minY, maxY, scaleY) {
const blocks = ['▁', '▂', '▃', '▄', '▅', '▆', '▇', '█'] // https://en.wikipedia.org/wiki/Block_Elements
const rows = new Array(scaleY).fill('')
for (const entry of data) {
const adjustedValue = (Math.max(Math.min(entry, maxY), minY) - minY) / (maxY - minY) * scaleY
const fraction = adjustedValue - Math.floor(adjustedValue)
for (let row = 0; row < scaleY; row++) {
if (adjustedValue > row) {
rows[row] += blocks[blocks.length - 1]
} else if (adjustedValue + 1 > row && fraction > 0) {
const scaledFraction = Math.floor(fraction * blocks.length)
rows[row] += blocks[scaledFraction]
} else {
rows[row] += ' '
}
}
}
return rows.reverse().join('\n')
}
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