Fix #1246

JetBrains · Nov 15, 2024 · c90515b · c90515b
1 parent 883f4c5
commit c90515b
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Showing 3 changed files with 26 additions and 2 deletions.
diff --git a/future_changes.md b/future_changes.md
@@ -12,4 +12,5 @@
 - Formatting when type='g' for large values throws exception [[#1239](https://github.com/JetBrains/lets-plot/issues/1239)].
 - Wrong formatting when type='s' with explicit precision [[#1240](https://github.com/JetBrains/lets-plot/issues/1240)].
 - Extra trim in formatted number when type='g' [[#1241](https://github.com/JetBrains/lets-plot/issues/1241)].
-- Axis breaks are badly formatted if explicitly set [[#1245](https://github.com/JetBrains/lets-plot/issues/1245)].
+- Axis breaks are badly formatted if explicitly set [[#1245](https://github.com/JetBrains/lets-plot/issues/1245)].
+- Badly formatted zero break for the "~g" format [[#1246](https://github.com/JetBrains/lets-plot/issues/1246)].
diff --git a/plot-base/src/commonMain/kotlin/org/jetbrains/letsPlot/core/commons/data/SeriesUtil.kt b/plot-base/src/commonMain/kotlin/org/jetbrains/letsPlot/core/commons/data/SeriesUtil.kt
@@ -9,6 +9,7 @@ import org.jetbrains.letsPlot.commons.geometry.DoubleVector
 import org.jetbrains.letsPlot.commons.intern.gcommon.collect.Iterables
 import org.jetbrains.letsPlot.commons.intern.gcommon.collect.Ordering
 import org.jetbrains.letsPlot.commons.interval.DoubleSpan
+import kotlin.math.absoluteValue
 import kotlin.math.log10
 import kotlin.math.max
 import kotlin.math.min
@@ -20,6 +21,23 @@ object SeriesUtil {
 
     private val REAL_NUMBER = { it: Double? -> isFinite(it) }
 
+
+    // Looks like zero when in v >= 0 and v < 1, and the first non-zero digit
+    // is at least 6 orders of magnitude smaller than step
+    fun isLooksLikeZero(v: Double, step: Double): Boolean {
+        if (v == 0.0) {
+            return true
+        }
+
+        if (v.absoluteValue >= 1.0) {
+            return false
+        }
+
+        val vPower = log10(v.absoluteValue)
+        val stepPower = log10(step)
+        return (vPower - stepPower) < -6
+    }
+
     fun isBeyondPrecision(range: DoubleSpan): Boolean {
         val delta = range.length
         return delta < TINY ||                       // ??

diff --git a/...ommonMain/kotlin/org/jetbrains/letsPlot/core/plot/base/scale/breaks/LinearBreaksHelper.kt b/...ommonMain/kotlin/org/jetbrains/letsPlot/core/plot/base/scale/breaks/LinearBreaksHelper.kt
@@ -90,7 +90,12 @@ internal class LinearBreaksHelper(
                 // don't allow ticks to go beyond the range
                 tick = min(tick, end)
 
-                breaks.add(tick)
+                if (SeriesUtil.isLooksLikeZero(tick, step)) {
+                    breaks.add(0.0)
+                } else {
+                    breaks.add(tick)
+                }
+
                 tick += step
             }