[statistics] Lower sumOfValuesBetween precision

apps/statistics/store.cpp

@@ -471,20 +471,23 @@ bool Store::updateSeries(int series, bool delayUpdate) {
 }
 
 double Store::sumOfValuesBetween(int series, double x1, double x2, bool strictUpperBound) const {
-  /* Use roughly_equal to handle impossible double representations such as
-   * 12.11 being 12.109999999999999 or 12.110000000000001. */
   if (!seriesIsValid(series)) {
     return NAN;
   }
+  /* Use roughly_equal to handle impossible double representations such as
+   * 12.11 being 12.109999999999999 or 12.110000000000001. The precision we use
+   * must be higher than 1e-14 (max number of significant digits) but having it
+   * higher than DBL_EPSILON wouldn't be effective. */
+  constexpr static double k_precision = 1e-15;
   double result = 0;
   int numberOfPairs = numberOfPairsOfSeries(series);
   for (int k = 0; k < numberOfPairs; k++) {
     int sortedIndex = valueIndexAtSortedIndex(series, k);
     double value = get(series, 0, sortedIndex);
-    if (value > x2 || (strictUpperBound && Poincare::Helpers::RelativelyEqual<double>(value, x2, DBL_EPSILON))) {
+    if (value > x2 || (strictUpperBound && Poincare::Helpers::RelativelyEqual<double>(value, x2, k_precision))) {
       break;
     }
-    if (value >= x1 || Poincare::Helpers::RelativelyEqual<double>(value, x1, DBL_EPSILON)) {
+    if (value >= x1 || Poincare::Helpers::RelativelyEqual<double>(value, x1, k_precision)) {
       result += get(series, 1, sortedIndex);
     }
   }