return Math.log(x) / LN_TEN;
};
+/**
+ * @private
+ * @param {number} r0
+ * @param {number} r1
+ * @param {number} pct
+ * @return {number}
+ */
+export var logRangeFraction = function(r0, r1, pct) {
+ // Computing the inverse of toPercentXCoord. The function was arrived at with
+ // the following steps:
+ //
+ // Original calcuation:
+ // pct = (log(x) - log(xRange[0])) / (log(xRange[1]) - log(xRange[0])));
+ //
+ // Multiply both sides by the right-side demoninator.
+ // pct * (log(xRange[1] - log(xRange[0]))) = log(x) - log(xRange[0])
+ //
+ // add log(xRange[0]) to both sides
+ // log(xRange[0]) + (pct * (log(xRange[1]) - log(xRange[0])) = log(x);
+ //
+ // Swap both sides of the equation,
+ // log(x) = log(xRange[0]) + (pct * (log(xRange[1]) - log(xRange[0]))
+ //
+ // Use both sides as the exponent in 10^exp and we're done.
+ // x = 10 ^ (log(xRange[0]) + (pct * (log(xRange[1]) - log(xRange[0])))
+
+ var logr0 = log10(r0);
+ var logr1 = log10(r1);
+ var exponent = logr0 + (pct * (logr1 - logr0));
+ var value = Math.pow(LOG_SCALE, exponent);
+ return value;
+};
+
/** A dotted line stroke pattern. */
export var DOTTED_LINE = [2, 2];
/** A dashed line stroke pattern. */