Initial data commit

Task/Gamma-function/BBC-BASIC/gamma-function.basic

@@ -0,0 +1,23 @@
+      *FLOAT64
+      INSTALL @lib$+"FNUSING"
+
+      FOR x = 0.1 TO 2.05 STEP 0.1
+        PRINT FNusing("#.#",x), FNusing("##.############", FNgamma(x))
+      NEXT
+      END
+
+      DEF FNgamma(z) = EXP(FNlngamma(z))
+
+      DEF FNlngamma(z)
+      LOCAL a, b, i%, lz()
+      DIM lz(6)
+      lz() = 1.000000000190015, 76.18009172947146, -86.50532032941677, \
+      \ 24.01409824083091, -1.231739572450155, 0.0012086509738662, -0.000005395239385
+      IF z < 0.5 THEN = LN(PI / SIN(PI * z)) - FNlngamma(1.0 - z)
+      z -= 1.0
+      b = z + 5.5
+      a = lz(0)
+      FOR i% = 1 TO 6
+        a += lz(i%) / (z + i%)
+      NEXT
+      = (LNSQR(2*PI) + LN(a) - b) + LN(b) * (z+0.5)