+
+ if (!this.attributes_.getForAxis("logscale", 'x')) {
+ return xRange[0] + (x - area.x) / area.w * (xRange[1] - xRange[0]);
+ } else {
+ // TODO: remove duplicate code?
+ // Computing the inverse of toDomCoord.
+ var pct = (x - area.x) / area.w;
+
+ // 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 = Dygraph.log10(xRange[0]);
+ var logr1 = Dygraph.log10(xRange[1]);
+ var exponent = logr0 + (pct * (logr1 - logr0));
+ var value = Math.pow(Dygraph.LOG_SCALE, exponent);
+ return value;
+ }