- * Add ticks when the x axis has numbers on it (instead of dates)
- *
- * @param {Number} minV minimum value
- * @param {Number} maxV maximum value
- * @param self
- * @param {function} attribute accessor function.
- * @return {[Object]} Array of {label, value} tuples.
- */
-Dygraph.numericTicks = function(minV, maxV, self, axis_props, vals) {
- var attr = function(k) {
- if (axis_props && axis_props.hasOwnProperty(k)) return axis_props[k];
- return self.attr_(k);
- };
-
- var ticks = [];
- if (vals) {
- for (var i = 0; i < vals.length; i++) {
- ticks.push({v: vals[i]});
- }
- } else {
- if (axis_props && attr("logscale")) {
- var pixelsPerTick = attr('pixelsPerYLabel');
- // NOTE(konigsberg): Dan, should self.height_ be self.plotter_.area.h?
- var nTicks = Math.floor(self.height_ / pixelsPerTick);
- var minIdx = Dygraph.binarySearch(minV, Dygraph.PREFERRED_LOG_TICK_VALUES, 1);
- var maxIdx = Dygraph.binarySearch(maxV, Dygraph.PREFERRED_LOG_TICK_VALUES, -1);
- if (minIdx == -1) {
- minIdx = 0;
- }
- if (maxIdx == -1) {
- maxIdx = Dygraph.PREFERRED_LOG_TICK_VALUES.length - 1;
- }
- // Count the number of tick values would appear, if we can get at least
- // nTicks / 4 accept them.
- var lastDisplayed = null;
- if (maxIdx - minIdx >= nTicks / 4) {
- var axisId = axis_props.yAxisId;
- for (var idx = maxIdx; idx >= minIdx; idx--) {
- var tickValue = Dygraph.PREFERRED_LOG_TICK_VALUES[idx];
- var domCoord = axis_props.g.toDomYCoord(tickValue, axisId);
- var tick = { v: tickValue };
- if (lastDisplayed == null) {
- lastDisplayed = {
- tickValue : tickValue,
- domCoord : domCoord
- };
- } else {
- if (domCoord - lastDisplayed.domCoord >= pixelsPerTick) {
- lastDisplayed = {
- tickValue : tickValue,
- domCoord : domCoord
- };
- } else {
- tick.label = "";
- }
- }
- ticks.push(tick);
- }
- // Since we went in backwards order.
- ticks.reverse();
- }
- }
-
- // ticks.length won't be 0 if the log scale function finds values to insert.
- if (ticks.length == 0) {
- // Basic idea:
- // Try labels every 1, 2, 5, 10, 20, 50, 100, etc.
- // Calculate the resulting tick spacing (i.e. this.height_ / nTicks).
- // The first spacing greater than pixelsPerYLabel is what we use.
- // TODO(danvk): version that works on a log scale.
- if (attr("labelsKMG2")) {
- var mults = [1, 2, 4, 8];
- } else {
- var mults = [1, 2, 5];
- }
- var scale, low_val, high_val, nTicks;
- // TODO(danvk): make it possible to set this for x- and y-axes independently.
- var pixelsPerTick = attr('pixelsPerYLabel');
- for (var i = -10; i < 50; i++) {
- if (attr("labelsKMG2")) {
- var base_scale = Math.pow(16, i);
- } else {
- var base_scale = Math.pow(10, i);
- }
- for (var j = 0; j < mults.length; j++) {
- scale = base_scale * mults[j];
- low_val = Math.floor(minV / scale) * scale;
- high_val = Math.ceil(maxV / scale) * scale;
- nTicks = Math.abs(high_val - low_val) / scale;
- var spacing = self.height_ / nTicks;
- // wish I could break out of both loops at once...
- if (spacing > pixelsPerTick) break;
- }
- if (spacing > pixelsPerTick) break;
- }
-
- // Construct the set of ticks.
- // Allow reverse y-axis if it's explicitly requested.
- if (low_val > high_val) scale *= -1;
- for (var i = 0; i < nTicks; i++) {
- var tickV = low_val + i * scale;
- ticks.push( {v: tickV} );
- }
- }