Add separate spoolup calculator

eos/utils/float.py

@@ -0,0 +1,26 @@
+"""
+Sometimes use of floats may lead to undesirable results, e.g.
+  int(2.3 / 0.1) = 22.
+We cannot afford to use different number representations (e.g. representations
+provided by decimal or fraction modules), thus consequences are worked around by
+this module.
+"""
+
+import math
+import sys
+
+
+# As we will be rounding numbers after operations (which introduce higher error
+# than base float representation error), we need to keep less significant
+# numbers than for single float number w/o operations
+keepDigits = int(sys.float_info.dig / 2)
+
+
+def floatUnerr(value):
+    """Round possible float number error, killing some precision in process."""
+    if value == 0:
+        return value
+    # Find round factor, taking into consideration that we want to keep at least
+    # predefined amount of significant digits
+    roundFactor = int(keepDigits - math.ceil(math.log10(abs(value))))
+    return round(value, roundFactor)