Initial commit

node_modules/d3-array/src/min.js

+export default function(values, valueof) {
+  var n = values.length,
+      i = -1,
+      value,
+      min;
+
+  if (valueof == null) {
+    while (++i < n) { // Find the first comparable value.
+      if ((value = values[i]) != null && value >= value) {
+        min = value;
+        while (++i < n) { // Compare the remaining values.
+          if ((value = values[i]) != null && min > value) {
+            min = value;
+          }
+        }
+      }
+    }
+  }
+
+  else {
+    while (++i < n) { // Find the first comparable value.
+      if ((value = valueof(values[i], i, values)) != null && value >= value) {
+        min = value;
+        while (++i < n) { // Compare the remaining values.
+          if ((value = valueof(values[i], i, values)) != null && min > value) {
+            min = value;
+          }
+        }
+      }
+    }
+  }
+
+  return min;
+}

node_modules/d3-array/src/number.js

+export default function(x) {
+  return x === null ? NaN : +x;
+}

node_modules/d3-array/src/pairs.js

+export default function(array, f) {
+  if (f == null) f = pair;
+  var i = 0, n = array.length - 1, p = array[0], pairs = new Array(n < 0 ? 0 : n);
+  while (i < n) pairs[i] = f(p, p = array[++i]);
+  return pairs;
+}
+
+export function pair(a, b) {
+  return [a, b];
+}

node_modules/d3-array/src/permute.js

+export default function(array, indexes) {
+  var i = indexes.length, permutes = new Array(i);
+  while (i--) permutes[i] = array[indexes[i]];
+  return permutes;
+}

node_modules/d3-array/src/quantile.js

+import number from "./number";
+
+export default function(values, p, valueof) {
+  if (valueof == null) valueof = number;
+  if (!(n = values.length)) return;
+  if ((p = +p) <= 0 || n < 2) return +valueof(values[0], 0, values);
+  if (p >= 1) return +valueof(values[n - 1], n - 1, values);
+  var n,
+      i = (n - 1) * p,
+      i0 = Math.floor(i),
+      value0 = +valueof(values[i0], i0, values),
+      value1 = +valueof(values[i0 + 1], i0 + 1, values);
+  return value0 + (value1 - value0) * (i - i0);
+}

node_modules/d3-array/src/range.js

+export default function(start, stop, step) {
+  start = +start, stop = +stop, step = (n = arguments.length) < 2 ? (stop = start, start = 0, 1) : n < 3 ? 1 : +step;
+
+  var i = -1,
+      n = Math.max(0, Math.ceil((stop - start) / step)) | 0,
+      range = new Array(n);
+
+  while (++i < n) {
+    range[i] = start + i * step;
+  }
+
+  return range;
+}

node_modules/d3-array/src/scan.js

+import ascending from "./ascending";
+
+export default function(values, compare) {
+  if (!(n = values.length)) return;
+  var n,
+      i = 0,
+      j = 0,
+      xi,
+      xj = values[j];
+
+  if (compare == null) compare = ascending;
+
+  while (++i < n) {
+    if (compare(xi = values[i], xj) < 0 || compare(xj, xj) !== 0) {
+      xj = xi, j = i;
+    }
+  }
+
+  if (compare(xj, xj) === 0) return j;
+}

node_modules/d3-array/src/shuffle.js

+export default function(array, i0, i1) {
+  var m = (i1 == null ? array.length : i1) - (i0 = i0 == null ? 0 : +i0),
+      t,
+      i;
+
+  while (m) {
+    i = Math.random() * m-- | 0;
+    t = array[m + i0];
+    array[m + i0] = array[i + i0];
+    array[i + i0] = t;
+  }
+
+  return array;
+}

node_modules/d3-array/src/sum.js

+export default function(values, valueof) {
+  var n = values.length,
+      i = -1,
+      value,
+      sum = 0;
+
+  if (valueof == null) {
+    while (++i < n) {
+      if (value = +values[i]) sum += value; // Note: zero and null are equivalent.
+    }
+  }
+
+  else {
+    while (++i < n) {
+      if (value = +valueof(values[i], i, values)) sum += value;
+    }
+  }
+
+  return sum;
+}

node_modules/d3-array/src/threshold/freedmanDiaconis.js

+import {map} from "../array";
+import ascending from "../ascending";
+import number from "../number";
+import quantile from "../quantile";
+
+export default function(values, min, max) {
+  values = map.call(values, number).sort(ascending);
+  return Math.ceil((max - min) / (2 * (quantile(values, 0.75) - quantile(values, 0.25)) * Math.pow(values.length, -1 / 3)));
+}

node_modules/d3-array/src/threshold/scott.js

+import deviation from "../deviation";
+
+export default function(values, min, max) {
+  return Math.ceil((max - min) / (3.5 * deviation(values) * Math.pow(values.length, -1 / 3)));
+}

node_modules/d3-array/src/threshold/sturges.js

+export default function(values) {
+  return Math.ceil(Math.log(values.length) / Math.LN2) + 1;
+}

node_modules/d3-array/src/ticks.js

+var e10 = Math.sqrt(50),
+    e5 = Math.sqrt(10),
+    e2 = Math.sqrt(2);
+
+export default function(start, stop, count) {
+  var reverse = stop < start,
+      i = -1,
+      n,
+      ticks,
+      step;
+
+  if (reverse) n = start, start = stop, stop = n;
+
+  if ((step = tickIncrement(start, stop, count)) === 0 || !isFinite(step)) return [];
+
+  if (step > 0) {
+    start = Math.ceil(start / step);
+    stop = Math.floor(stop / step);
+    ticks = new Array(n = Math.ceil(stop - start + 1));
+    while (++i < n) ticks[i] = (start + i) * step;
+  } else {
+    start = Math.floor(start * step);
+    stop = Math.ceil(stop * step);
+    ticks = new Array(n = Math.ceil(start - stop + 1));
+    while (++i < n) ticks[i] = (start - i) / step;
+  }
+
+  if (reverse) ticks.reverse();
+
+  return ticks;
+}
+
+export function tickIncrement(start, stop, count) {
+  var step = (stop - start) / Math.max(0, count),
+      power = Math.floor(Math.log(step) / Math.LN10),
+      error = step / Math.pow(10, power);
+  return power >= 0
+      ? (error >= e10 ? 10 : error >= e5 ? 5 : error >= e2 ? 2 : 1) * Math.pow(10, power)
+      : -Math.pow(10, -power) / (error >= e10 ? 10 : error >= e5 ? 5 : error >= e2 ? 2 : 1);
+}
+
+export function tickStep(start, stop, count) {
+  var step0 = Math.abs(stop - start) / Math.max(0, count),
+      step1 = Math.pow(10, Math.floor(Math.log(step0) / Math.LN10)),
+      error = step0 / step1;
+  if (error >= e10) step1 *= 10;
+  else if (error >= e5) step1 *= 5;
+  else if (error >= e2) step1 *= 2;
+  return stop < start ? -step1 : step1;
+}

node_modules/d3-array/src/transpose.js

+import min from "./min";
+
+export default function(matrix) {
+  if (!(n = matrix.length)) return [];
+  for (var i = -1, m = min(matrix, length), transpose = new Array(m); ++i < m;) {
+    for (var j = -1, n, row = transpose[i] = new Array(n); ++j < n;) {
+      row[j] = matrix[j][i];
+    }
+  }
+  return transpose;
+}
+
+function length(d) {
+  return d.length;
+}

node_modules/d3-array/src/variance.js

+import number from "./number";
+
+export default function(values, valueof) {
+  var n = values.length,
+      m = 0,
+      i = -1,
+      mean = 0,
+      value,
+      delta,
+      sum = 0;
+
+  if (valueof == null) {
+    while (++i < n) {
+      if (!isNaN(value = number(values[i]))) {
+        delta = value - mean;
+        mean += delta / ++m;
+        sum += delta * (value - mean);
+      }
+    }
+  }
+
+  else {
+    while (++i < n) {
+      if (!isNaN(value = number(valueof(values[i], i, values)))) {
+        delta = value - mean;
+        mean += delta / ++m;
+        sum += delta * (value - mean);
+      }
+    }
+  }
+
+  if (m > 1) return sum / (m - 1);
+}

node_modules/d3-array/src/zip.js

+import transpose from "./transpose";
+
+export default function() {
+  return transpose(arguments);
+}

node_modules/d3-axis/.eslintrc

+parserOptions:
+    sourceType: module
+
+extends:
+    "eslint:recommended"
+
+rules:
+    no-cond-assign: 0

node_modules/d3-axis/.npmignore

+*.sublime-*
+build/*.zip
+test/

node_modules/d3-axis/LICENSE

+Copyright 2010-2016 Mike Bostock
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
+
+* Redistributions of source code must retain the above copyright notice, this
+  list of conditions and the following disclaimer.
+
+* Redistributions in binary form must reproduce the above copyright notice,
+  this list of conditions and the following disclaimer in the documentation
+  and/or other materials provided with the distribution.
+
+* Neither the name of the author nor the names of contributors may be used to
+  endorse or promote products derived from this software without specific prior
+  written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

node_modules/d3-axis/README.md

+# d3-axis
+
+The axis component renders human-readable reference marks for [scales](https://github.com/d3/d3-scale). This alleviates one of the more tedious tasks in visualizing data.
+
+## Installing
+
+If you use NPM, `npm install d3-axis`. Otherwise, download the [latest release](https://github.com/d3/d3-axis/releases/latest). You can also load directly from [d3js.org](https://d3js.org), either as a [standalone library](https://d3js.org/d3-axis.v1.min.js) or as part of [D3 4.0](https://github.com/d3/d3). (To be useful, you’ll also want to use [d3-scale](https://github.com/d3/d3-scale) and [d3-selection](https://github.com/d3/d3-selection), but these are soft dependencies.) AMD, CommonJS, and vanilla environments are supported. In vanilla, a `d3` global is exported:
+
+```html
+<script src="https://d3js.org/d3-axis.v1.min.js"></script>
+<script>
+
+var axis = d3.axisLeft(scale);
+
+</script>
+```
+
+[Try d3-axis in your browser.](https://tonicdev.com/npm/d3-axis)
+
+## API Reference
+
+Regardless of orientation, axes are always rendered at the origin. To change the position of the axis with respect to the chart, specify a [transform attribute](http://www.w3.org/TR/SVG/coords.html#TransformAttribute) on the containing element. For example:
+
+```js
+d3.select("body").append("svg")
+    .attr("width", 1440)
+    .attr("height", 30)
+  .append("g")
+    .attr("transform", "translate(0,30)")
+    .call(axis);
+```
+
+The elements created by the axis are considered part of its public API. You can apply external stylesheets or modify the generated axis elements to [customize the axis appearance](https://bl.ocks.org/mbostock/3371592).
+
+[<img alt="Custom Axis" src="https://raw.githubusercontent.com/d3/d3-axis/master/img/custom.png" width="420" height="219">](http://bl.ocks.org/mbostock/3371592)
+
+An axis consists of a [path element](https://www.w3.org/TR/SVG/paths.html#PathElement) of class “domain” representing the extent of the scale’s domain, followed by transformed [g elements](https://www.w3.org/TR/SVG/struct.html#Groups) of class “tick” representing each of the scale’s ticks. Each tick has a [line element](https://www.w3.org/TR/SVG/shapes.html#LineElement) to draw the tick line, and a [text element](https://www.w3.org/TR/SVG/text.html#TextElement) for the tick label. For example, here is a typical bottom-oriented axis:
+
+```html
+<g fill="none" font-size="10" font-family="sans-serif" text-anchor="middle">
+  <path class="domain" stroke="#000" d="M0.5,6V0.5H880.5V6"></path>
+  <g class="tick" opacity="1" transform="translate(0.5,0)">
+    <line stroke="#000" y2="6"></line>
+    <text fill="#000" y="9" dy="0.71em">0.0</text>
+  </g>
+  <g class="tick" opacity="1" transform="translate(176.5,0)">
+    <line stroke="#000" y2="6"></line>
+    <text fill="#000" y="9" dy="0.71em">0.2</text>
+  </g>
+  <g class="tick" opacity="1" transform="translate(352.5,0)">
+    <line stroke="#000" y2="6"></line>
+    <text fill="#000" y="9" dy="0.71em">0.4</text>
+  </g>
+  <g class="tick" opacity="1" transform="translate(528.5,0)">
+    <line stroke="#000" y2="6"></line>
+    <text fill="#000" y="9" dy="0.71em">0.6</text>
+  </g>
+  <g class="tick" opacity="1" transform="translate(704.5,0)">
+    <line stroke="#000" y2="6"></line>
+    <text fill="#000" y="9" dy="0.71em">0.8</text>
+  </g>
+  <g class="tick" opacity="1" transform="translate(880.5,0)">
+    <line stroke="#000" y2="6"></line>
+    <text fill="#000" y="9" dy="0.71em">1.0</text>
+  </g>
+</g>
+```
+
+The orientation of an axis is fixed; to change the orientation, remove the old axis and create a new axis.
+
+<a name="axisTop" href="#axisTop">#</a> d3.<b>axisTop</b>(<i>scale</i>) [<>](https://github.com/d3/d3-axis/blob/master/src/axis.js#L159 "Source")
+
+Constructs a new top-oriented axis generator for the given [scale](https://github.com/d3/d3-scale), with empty [tick arguments](#axis_ticks), a [tick size](#axis_tickSize) of 6 and [padding](#axis_tickPadding) of 3. In this orientation, ticks are drawn above the horizontal domain path.
+
+<a name="axisRight" href="#axisRight">#</a> d3.<b>axisRight</b>(<i>scale</i>) [<>](https://github.com/d3/d3-axis/blob/master/src/axis.js#L163 "Source")
+
+Constructs a new right-oriented axis generator for the given [scale](https://github.com/d3/d3-scale), with empty [tick arguments](#axis_ticks), a [tick size](#axis_tickSize) of 6 and [padding](#axis_tickPadding) of 3. In this orientation, ticks are drawn to the right of the vertical domain path.
+
+<a name="axisBottom" href="#axisBottom">#</a> d3.<b>axisBottom</b>(<i>scale</i>) [<>](https://github.com/d3/d3-axis/blob/master/src/axis.js#L167 "Source")
+
+Constructs a new bottom-oriented axis generator for the given [scale](https://github.com/d3/d3-scale), with empty [tick arguments](#axis_ticks), a [tick size](#axis_tickSize) of 6 and [padding](#axis_tickPadding) of 3. In this orientation, ticks are drawn below the horizontal domain path.
+
+<a name="axisLeft" href="#axisLeft">#</a> d3.<b>axisLeft</b>(<i>scale</i>) [<>](https://github.com/d3/d3-axis/blob/master/src/axis.js#L171 "Source")
+
+Constructs a new left-oriented axis generator for the given [scale](https://github.com/d3/d3-scale), with empty [tick arguments](#axis_ticks), a [tick size](#axis_tickSize) of 6 and [padding](#axis_tickPadding) of 3. In this orientation, ticks are drawn to the left of the vertical domain path.
+
+<a name="_axis" href="#_axis">#</a> <i>axis</i>(<i>context</i>) [<>](https://github.com/d3/d3-axis/blob/master/src/axis.js#L40 "Source")
+
+Render the axis to the given *context*, which may be either a [selection](https://github.com/d3/d3-selection) of SVG containers (either SVG or G elements) or a corresponding [transition](https://github.com/d3/d3-transition).
+
+<a name="axis_scale" href="#axis_scale">#</a> <i>axis</i>.<b>scale</b>([<i>scale</i>]) [<>](https://github.com/d3/d3-axis/blob/master/src/axis.js#L120 "Source")
+
+If *scale* is specified, sets the [scale](https://github.com/d3/d3-scale) and returns the axis. If *scale* is not specified, returns the current scale.
+
+<a name="axis_ticks" href="#axis_ticks">#</a> <i>axis</i>.<b>ticks</b>(<i>arguments…</i>) [<>](https://github.com/d3/d3-axis/blob/master/src/axis.js#L124 "Source")
+<br><a href="#axis_ticks">#</a> <i>axis</i>.<b>ticks</b>([<i>count</i>[, <i>specifier</i>]])
+<br><a href="#axis_ticks">#</a> <i>axis</i>.<b>ticks</b>([<i>interval</i>[, <i>specifier</i>]])
+
+Sets the *arguments* that will be passed to [*scale*.ticks](https://github.com/d3/d3-scale/blob/master/README.md#continuous_ticks) and [*scale*.tickFormat](https://github.com/d3/d3-scale/blob/master/README.md#continuous_tickFormat) when the axis is [rendered](#_axis), and returns the axis generator. The meaning of the *arguments* depends on the [axis’ scale](#axis_scale) type: most commonly, the arguments are a suggested *count* for the number of ticks (or a [time *interval*](https://github.com/d3/d3-time) for time scales), and an optional [format *specifier*](https://github.com/d3/d3-format) to customize how the tick values are formatted.
+
+This method has no effect if the scale does not implement *scale*.ticks, as with [band](https://github.com/d3/d3-scale/blob/master/README.md#band-scales) and [point](https://github.com/d3/d3-scale/blob/master/README.md#point-scales) scales. To set the tick values explicitly, use [*axis*.tickValues](#axis_tickValues). To set the tick format explicitly, use [*axis*.tickFormat](#axis_tickFormat).
+
+For example, to generate twenty ticks with SI-prefix formatting on a linear scale, say:
+
+```js
+axis.ticks(20, "s");
+```
+
+To generate ticks every fifteen minutes with a time scale, say:
+
+```js
+axis.ticks(d3.timeMinute.every(15));
+```
+
+This method is also a convenience function for [*axis*.tickArguments](#axis_tickArguments). For example, this:
+
+```js
+axis.ticks(10);
+```
+
+Is equivalent to:
+
+```js
+axis.tickArguments([10]);
+```
+
+<a name="axis_tickArguments" href="#axis_tickArguments">#</a> <i>axis</i>.<b>tickArguments</b>([<i>arguments</i>]) [<>](https://github.com/d3/d3-axis/blob/master/src/axis.js#L128 "Source")
+
+If *arguments* is specified, sets the *arguments* that will be passed to [*scale*.ticks](https://github.com/d3/d3-scale/blob/master/README.md#continuous_ticks) and [*scale*.tickFormat](https://github.com/d3/d3-scale/blob/master/README.md#continuous_tickFormat) when the axis is [rendered](#_axis), and returns the axis generator. The meaning of the *arguments* depends on the [axis’ scale](#axis_scale) type: most commonly, the arguments are a suggested *count* for the number of ticks (or a [time *interval*](https://github.com/d3/d3-time) for time scales), and an optional [format *specifier*](https://github.com/d3/d3-format) to customize how the tick values are formatted.
+
+If *arguments* is specified, this method has no effect if the scale does not implement *scale*.ticks, as with [band](https://github.com/d3/d3-scale/blob/master/README.md#band-scales) and [point](https://github.com/d3/d3-scale/blob/master/README.md#point-scales) scales. To set the tick values explicitly, use [*axis*.tickValues](#axis_tickValues). To set the tick format explicitly, use [*axis*.tickFormat](#axis_tickFormat).
+
+If *arguments* is not specified, returns the current tick arguments, which defaults to the empty array.
+
+For example, to generate twenty ticks with SI-prefix formatting on a linear scale, say:
+
+```js
+axis.tickArguments([20, "s"]);
+```
+
+To generate ticks every fifteen minutes with a time scale, say:
+
+```js
+axis.tickArguments([d3.timeMinute.every(15)]);
+```
+
+See also [*axis*.ticks](#axis_ticks).
+
+<a name="axis_tickValues" href="#axis_tickValues">#</a> <i>axis</i>.<b>tickValues</b>([<i>values</i>]) [<>](https://github.com/d3/d3-axis/blob/master/src/axis.js#L132 "Source")
+
+If a *values* array is specified, the specified values are used for ticks rather than using the scale’s automatic tick generator. If *values* is null, clears any previously-set explicit tick values and reverts back to the scale’s tick generator. If *values* is not specified, returns the current tick values, which defaults to null. For example, to generate ticks at specific values:
+
+```js
+var xAxis = d3.axisBottom(x)
+    .tickValues([1, 2, 3, 5, 8, 13, 21]);
+```
+
+The explicit tick values take precedent over the tick arguments set by [*axis*.tickArguments](#axis_tickArguments). However, any tick arguments will still be passed to the scale’s [tickFormat](#axis_tickFormat) function if a tick format is not also set.
+
+<a name="axis_tickFormat" href="#axis_tickFormat">#</a> <i>axis</i>.<b>tickFormat</b>([<i>format</i>]) [<>](https://github.com/d3/d3-axis/blob/master/src/axis.js#L136 "Source")
+
+If *format* is specified, sets the tick format function and returns the axis. If *format* is not specified, returns the current format function, which defaults to null. A null format indicates that the scale’s default formatter should be used, which is generated by calling [*scale*.tickFormat](https://github.com/d3/d3-scale/blob/master/README.md#continuous_tickFormat). In this case, the arguments specified by [*axis*.tickArguments](#axis_tickArguments) are likewise passed to *scale*.tickFormat.
+
+See [d3-format](https://github.com/d3/d3-format) and [d3-time-format](https://github.com/d3/d3-time-format) for help creating formatters. For example, to display integers with comma-grouping for thousands:
+
+```js
+axis.tickFormat(d3.format(",.0f"));
+```
+
+More commonly, a format specifier is passed to [*axis*.ticks](#axis_ticks):
+
+```js
+axis.ticks(10, ",f");
+```
+
+This has the advantage of setting the format precision automatically based on the tick interval.
+
+<a name="axis_tickSize" href="#axis_tickSize">#</a> <i>axis</i>.<b>tickSize</b>([<i>size</i>]) [<>](https://github.com/d3/d3-axis/blob/master/src/axis.js#L140 "Source")
+
+If *size* is specified, sets the [inner](#axis_tickSizeInner) and [outer](#axis_tickSizeOuter) tick size to the specified value and returns the axis. If *size* is not specified, returns the current inner tick size, which defaults to 6.
+
+<a name="axis_tickSizeInner" href="#axis_tickSizeInner">#</a> <i>axis</i>.<b>tickSizeInner</b>([<i>size</i>]) [<>](https://github.com/d3/d3-axis/blob/master/src/axis.js#L144 "Source")
+
+If *size* is specified, sets the inner tick size to the specified value and returns the axis. If *size* is not specified, returns the current inner tick size, which defaults to 6. The inner tick size controls the length of the tick lines, offset from the native position of the axis.
+
+<a name="axis_tickSizeOuter" href="#axis_tickSizeOuter">#</a> <i>axis</i>.<b>tickSizeOuter</b>([<i>size</i>]) [<>](https://github.com/d3/d3-axis/blob/master/src/axis.js#L148 "Source")
+
+If *size* is specified, sets the outer tick size to the specified value and returns the axis. If *size* is not specified, returns the current outer tick size, which defaults to 6. The outer tick size controls the length of the square ends of the domain path, offset from the native position of the axis. Thus, the “outer ticks” are not actually ticks but part of the domain path, and their position is determined by the associated scale’s domain extent. Thus, outer ticks may overlap with the first or last inner tick. An outer tick size of 0 suppresses the square ends of the domain path, instead producing a straight line.
+
+<a name="axis_tickPadding" href="#axis_tickPadding">#</a> <i>axis</i>.<b>tickPadding</b>([<i>padding</i>]) [<>](https://github.com/d3/d3-axis/blob/master/src/axis.js#L152 "Source")
+
+If *padding* is specified, sets the padding to the specified value in pixels and returns the axis. If *padding* is not specified, returns the current padding which defaults to 3 pixels.