### v2.1.8
Fixed a crash
### v2.1.7
1.Supports unit converter
2.Added settings to right-justify digits
of results.
3.Added settings to fix the number of
digits after the decimal point.
4.Supports aggregate functions
(sum,avg,max,min,var,stdev,median)
5.Supports trigonometric function using
the grade.
6.Organized the preferences.
7.Added whitespace to button
actions.
8.Fixed minor bugs.
### v2.0.6
1. Fixed a bug that failed to save a
file.