plotly.js
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The open source javascript graphing library that powers plotly
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JavaScript
/**
* Copyright 2012-2020, Plotly, Inc.
* All rights reserved.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*/
;
var numConstants = require('../../constants/numerical');
var oneYear = numConstants.ONEAVGYEAR;
var oneMonth = numConstants.ONEAVGMONTH;
var oneDay = numConstants.ONEDAY;
var oneHour = numConstants.ONEHOUR;
var oneMin = numConstants.ONEMIN;
var oneSec = numConstants.ONESEC;
var tickIncrement = require('../../plots/cartesian/axes').tickIncrement;
/*
* make a function that will find rounded bin edges
* @param {number} leftGap: how far from the left edge of any bin is the closest data value?
* @param {number} rightGap: how far from the right edge of any bin is the closest data value?
* @param {Array[number]} binEdges: the actual edge values used in binning
* @param {object} pa: the position axis
* @param {string} calendar: the data calendar
*
* @return {function(v, isRightEdge)}:
* find the start (isRightEdge is falsy) or end (truthy) label value for a bin edge `v`
*/
module.exports = function getBinSpanLabelRound(leftGap, rightGap, binEdges, pa, calendar) {
// the rounding digit is the largest digit that changes in *all* of 4 regions:
// - inside the rightGap before binEdges[0] (shifted 10% to the left)
// - inside the leftGap after binEdges[0] (expanded by 10% of rightGap on each end)
// - same for binEdges[1]
var dv0 = -1.1 * rightGap;
var dv1 = -0.1 * rightGap;
var dv2 = leftGap - dv1;
var edge0 = binEdges[0];
var edge1 = binEdges[1];
var leftDigit = Math.min(
biggestDigitChanged(edge0 + dv1, edge0 + dv2, pa, calendar),
biggestDigitChanged(edge1 + dv1, edge1 + dv2, pa, calendar)
);
var rightDigit = Math.min(
biggestDigitChanged(edge0 + dv0, edge0 + dv1, pa, calendar),
biggestDigitChanged(edge1 + dv0, edge1 + dv1, pa, calendar)
);
// normally we try to make the label for the right edge different from
// the left edge label, so it's unambiguous which bin gets data on the edge.
// but if this results in more than 3 extra digits (or for dates, more than
// 2 fields ie hr&min or min&sec, which is 3600x), it'll be more clutter than
// useful so keep the label cleaner instead
var digit, disambiguateEdges;
if(leftDigit > rightDigit && rightDigit < Math.abs(edge1 - edge0) / 4000) {
digit = leftDigit;
disambiguateEdges = false;
} else {
digit = Math.min(leftDigit, rightDigit);
disambiguateEdges = true;
}
if(pa.type === 'date' && digit > oneDay) {
var dashExclude = (digit === oneYear) ? 1 : 6;
var increment = (digit === oneYear) ? 'M12' : 'M1';
return function(v, isRightEdge) {
var dateStr = pa.c2d(v, oneYear, calendar);
var dashPos = dateStr.indexOf('-', dashExclude);
if(dashPos > 0) dateStr = dateStr.substr(0, dashPos);
var roundedV = pa.d2c(dateStr, 0, calendar);
if(roundedV < v) {
var nextV = tickIncrement(roundedV, increment, false, calendar);
if((roundedV + nextV) / 2 < v + leftGap) roundedV = nextV;
}
if(isRightEdge && disambiguateEdges) {
return tickIncrement(roundedV, increment, true, calendar);
}
return roundedV;
};
}
return function(v, isRightEdge) {
var roundedV = digit * Math.round(v / digit);
// if we rounded down and we could round up and still be < leftGap
// (or what leftGap values round to), do that
if(roundedV + (digit / 10) < v && roundedV + (digit * 0.9) < v + leftGap) {
roundedV += digit;
}
// finally for the right edge back off one digit - but only if we can do that
// and not clip off any data that's potentially in the bin
if(isRightEdge && disambiguateEdges) {
roundedV -= digit;
}
return roundedV;
};
};
/*
* Find the largest digit that changes within a (calcdata) region [v1, v2]
* if dates, "digit" means date/time part when it's bigger than a second
* returns the unit value to round to this digit, eg 0.01 to round to hundredths, or
* 100 to round to hundreds. returns oneMonth or oneYear for month or year rounding,
* so that Math.min will work, rather than 'M1' and 'M12'
*/
function biggestDigitChanged(v1, v2, pa, calendar) {
// are we crossing zero? can't say anything.
// in principle this doesn't apply to dates but turns out this doesn't matter.
if(v1 * v2 <= 0) return Infinity;
var dv = Math.abs(v2 - v1);
var isDate = pa.type === 'date';
var digit = biggestGuaranteedDigitChanged(dv, isDate);
// see if a larger digit also changed
for(var i = 0; i < 10; i++) {
// numbers: next digit needs to be >10x but <100x then gets rounded down.
// dates: next digit can be as much as 60x (then rounded down)
var nextDigit = biggestGuaranteedDigitChanged(digit * 80, isDate);
// if we get to years, the chain stops
if(digit === nextDigit) break;
if(didDigitChange(nextDigit, v1, v2, isDate, pa, calendar)) digit = nextDigit;
else break;
}
return digit;
}
/*
* Find the largest digit that *definitely* changes in a region [v, v + dv] for any v
* for nonuniform date regions (months/years) pick the largest
*/
function biggestGuaranteedDigitChanged(dv, isDate) {
if(isDate && dv > oneSec) {
// this is supposed to be the biggest *guaranteed* change
// so compare to the longest month and year across any calendar,
// and we'll iterate back up later
// note: does not support rounding larger than one year. We could add
// that if anyone wants it, but seems unusual and not strictly necessary.
if(dv > oneDay) {
if(dv > oneYear * 1.1) return oneYear;
if(dv > oneMonth * 1.1) return oneMonth;
return oneDay;
}
if(dv > oneHour) return oneHour;
if(dv > oneMin) return oneMin;
return oneSec;
}
return Math.pow(10, Math.floor(Math.log(dv) / Math.LN10));
}
function didDigitChange(digit, v1, v2, isDate, pa, calendar) {
if(isDate && digit > oneDay) {
var dateParts1 = dateParts(v1, pa, calendar);
var dateParts2 = dateParts(v2, pa, calendar);
var parti = (digit === oneYear) ? 0 : 1;
return dateParts1[parti] !== dateParts2[parti];
}
return Math.floor(v2 / digit) - Math.floor(v1 / digit) > 0.1;
}
function dateParts(v, pa, calendar) {
var parts = pa.c2d(v, oneYear, calendar).split('-');
if(parts[0] === '') {
parts.unshift();
parts[0] = '-' + parts[0];
}
return parts;
}