+// This is a list of human-friendly values at which to show tick marks on a log
+// scale. It is k * 10^n, where k=1..9 and n=-39..+39, so:
+// ..., 1, 2, 3, 4, 5, ..., 9, 10, 20, 30, ..., 90, 100, 200, 300, ...
+// NOTE: this assumes that Dygraph.LOG_SCALE = 10.
+Dygraph.PREFERRED_LOG_TICK_VALUES = function() {
+ var vals = [];
+ for (var power = -39; power <= 39; power++) {
+ var range = Math.pow(10, power);
+ for (var mult = 1; mult <= 9; mult++) {
+ var val = range * mult;
+ vals.push(val);
+ }
+ }
+ return vals;
+}();
+
+// val is the value to search for
+// arry is the value over which to search
+// if abs > 0, find the lowest entry greater than val
+// if abs < 0, find the highest entry less than val
+// if abs == 0, find the entry that equals val.
+// Currently does not work when val is outside the range of arry's values.
+Dygraph.binarySearch = function(val, arry, abs, low, high) {
+ if (low == null || high == null) {
+ low = 0;
+ high = arry.length - 1;
+ }
+ if (low > high) {
+ return -1;
+ }
+ if (abs == null) {
+ abs = 0;
+ }
+ var validIndex = function(idx) {
+ return idx >= 0 && idx < arry.length;
+ }
+ var mid = parseInt((low + high) / 2);
+ var element = arry[mid];
+ if (element == val) {
+ return mid;
+ }
+ if (element > val) {
+ if (abs > 0) {
+ // Accept if element > val, but also if prior element < val.
+ var idx = mid - 1;
+ if (validIndex(idx) && arry[idx] < val) {
+ return mid;
+ }
+ }
+ return Dygraph.binarySearch(val, arry, abs, low, mid - 1);
+ }
+ if (element < val) {
+ if (abs < 0) {
+ // Accept if element < val, but also if prior element > val.
+ var idx = mid + 1;
+ if (validIndex(idx) && arry[idx] > val) {
+ return mid;
+ }
+ }
+ return Dygraph.binarySearch(val, arry, abs, mid + 1, high);
+ }
+};
+
+/**
+ * Determine the number of significant figures in a Number up to the specified
+ * precision. Note that there is no way to determine if a trailing '0' is
+ * significant or not, so by convention we return 1 for all of the following
+ * inputs: 1, 1.0, 1.00, 1.000 etc.
+ * @param {Number} x The input value.
+ * @param {Number} opt_maxPrecision Optional maximum precision to consider.
+ * Default and maximum allowed value is 13.
+ * @return {Number} The number of significant figures which is >= 1.
+ */
+Dygraph.significantFigures = function(x, opt_maxPrecision) {
+ var precision = Math.max(opt_maxPrecision || 13, 13);
+
+ // Convert the number to its exponential notation form and work backwards,
+ // ignoring the 'e+xx' bit. This may seem like a hack, but doing a loop and
+ // dividing by 10 leads to roundoff errors. By using toExponential(), we let
+ // the JavaScript interpreter handle the low level bits of the Number for us.
+ var s = x.toExponential(precision);
+ var ePos = s.lastIndexOf('e'); // -1 case handled by return below.
+
+ for (var i = ePos - 1; i >= 0; i--) {
+ if (s[i] == '.') {
+ // Got to the decimal place. We'll call this 1 digit of precision because
+ // we can't know for sure how many trailing 0s are significant.
+ return 1;
+ } else if (s[i] != '0') {
+ // Found the first non-zero digit. Return the number of characters
+ // except for the '.'.
+ return i; // This is i - 1 + 1 (-1 is for '.', +1 is for 0 based index).
+ }
+ }
+
+ // Occurs if toExponential() doesn't return a string containing 'e', which
+ // should never happen.
+ return 1;
+};
+
projects / dygraphs.git / blobdiff