diff --git a/src/scale/Log.ts b/src/scale/Log.ts
index b1f4d08b16..8918c68370 100644
--- a/src/scale/Log.ts
+++ b/src/scale/Log.ts
@@ -36,9 +36,25 @@ const roundingErrorFix = numberUtil.round;
const mathFloor = Math.floor;
const mathCeil = Math.ceil;
const mathPow = Math.pow;
-
const mathLog = Math.log;
+/**
+ * symmetric log, allowing negative values for logarithmic scales
+ */
+function symMathLog(x: number): number {
+ if (x === 0) {
+ return 0;
+ }
+ return x > 0 ? mathLog(x) : -mathLog(-x);
+}
+
+/**
+ * symmetric pow, allowing negative values for logarithmic scales
+ */
+function symMathPow(x: number, y: number): number {
+ return y >= 0 ? mathPow(x, y) : -mathPow(x, -y);
+}
+
class LogScale extends Scale {
static type = 'log';
readonly type = 'log';
@@ -68,7 +84,7 @@ class LogScale extends Scale {
return zrUtil.map(ticks, function (tick) {
const val = tick.value;
- let powVal = numberUtil.round(mathPow(this.base, val));
+ let powVal = numberUtil.round(symMathPow(this.base, val));
// Fix #4158
powVal = (val === extent[0] && this._fixMin)
@@ -86,9 +102,8 @@ class LogScale extends Scale {
setExtent(start: number, end: number): void {
const base = mathLog(this.base);
- // log(-Infinity) is NaN, so safe guard here
- start = mathLog(Math.max(0, start)) / base;
- end = mathLog(Math.max(0, end)) / base;
+ start = symMathLog(start) / base;
+ end = symMathLog(end) / base;
intervalScaleProto.setExtent.call(this, start, end);
}
@@ -98,8 +113,8 @@ class LogScale extends Scale {
getExtent() {
const base = this.base;
const extent = scaleProto.getExtent.call(this);
- extent[0] = mathPow(base, extent[0]);
- extent[1] = mathPow(base, extent[1]);
+ extent[0] = symMathPow(base, extent[0]);
+ extent[1] = symMathPow(base, extent[1]);
// Fix #4158
const originalScale = this._originalScale;
@@ -114,8 +129,8 @@ class LogScale extends Scale {
this._originalScale.unionExtent(extent);
const base = this.base;
- extent[0] = mathLog(extent[0]) / mathLog(base);
- extent[1] = mathLog(extent[1]) / mathLog(base);
+ extent[0] = symMathLog(extent[0]) / mathLog(base);
+ extent[1] = symMathLog(extent[1]) / mathLog(base);
scaleProto.unionExtent.call(this, extent);
}
@@ -177,18 +192,18 @@ class LogScale extends Scale {
}
contain(val: number): boolean {
- val = mathLog(val) / mathLog(this.base);
+ val = symMathLog(val) / mathLog(this.base);
return scaleHelper.contain(val, this._extent);
}
normalize(val: number): number {
- val = mathLog(val) / mathLog(this.base);
+ val = symMathLog(val) / mathLog(this.base);
return scaleHelper.normalize(val, this._extent);
}
scale(val: number): number {
val = scaleHelper.scale(val, this._extent);
- return mathPow(this.base, val);
+ return symMathPow(this.base, val);
}
getMinorTicks: IntervalScale['getMinorTicks'];
diff --git a/test/bar-log-negative.html b/test/bar-log-negative.html
new file mode 100644
index 0000000000..a9c6342bf0
--- /dev/null
+++ b/test/bar-log-negative.html
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