migrate basic functions

Author: lindahua

src/stats.jl

@@ -0,0 +1,26 @@
+# mathematical constants related to statistics
+
+@irrational twoπ   6.2831853071795864769 big(π) * 2.0
+@irrational fourπ  12.566370614359172954 big(π) * 4.0
+@irrational halfπ  1.5707963267948966192 big(π) * 0.5
+@irrational quartπ 0.7853981633974483096 big(π) * 0.25
+
+@irrational invπ     0.31830988618379067154 inv(big(π))
+@irrational twoinvπ  0.63661977236758134308 big(invπ) * 2.0
+@irrational fourinvπ 1.27323954473516268615 big(invπ) * 4.0
+@irrational inv2π    0.159154943091895335769 big(invπ) * 0.5
+@irrational inv4π    0.079577471545947667884 big(invπ) * 0.25
+
+@irrational sqrt2     1.4142135623730950488 sqrt(big(2.0))
+@irrational sqrt3     1.7320508075688772935 sqrt(big(3.0))
+@irrational sqrtπ     1.7724538509055160273 sqrt(big(π))
+@irrational sqrt2π    2.5066282746310005024 sqrt(big(π) * 2.0)
+@irrational sqrt4π    3.5449077018110320546 sqrt(big(π) * 4.0)
+@irrational sqrthalfπ 1.2533141373155002512 sqrt(big(0.5)*π)
+
+@irrational logtwo 0.6931471805599453094 log(big(2.))
+@irrational logπ   1.1447298858494001741 log(big(π))
+@irrational log2π  1.8378770664093454836 log(big(2.)*π)
+@irrational log4π  2.5310242469692907930 log(big(4.)*π)
+
+@irrational loghalf -0.6931471805599453094 log(big(0.5))