plot: Fix SCI formatter (#114)

Author: johannes-wolf

src/plot/formats.typ

@@ -128,7 +128,7 @@
     0
   }
 
-  let ee = calc.pow(10, calc.abs(exponent + 1))
+  let ee = calc.pow(10.0, calc.abs(exponent + 1))
   if exponent > 0 {
     value = value / ee * 10
   } else if exponent < 0 {

tests/plot/format/ref/1.png

@@ -37,3 +37,15 @@
     plot.add(data)
   })
 })
+
+#test-case({
+  plot.plot(
+    size: (8, 4),
+    x-min: -1e10,
+    x-max: +1e10,
+    x-tick-step: 1e10,
+    y-format: none,
+    x-format: plot.formats.sci, {
+    plot.add(data)
+  })
+})