Data update

Task/Gamma-function/Agena/gamma-function.agena

@@ -0,0 +1,26 @@
+# Gamma function
+
+proc ln_gamma(z :: number) :: number is
+  lz := reg(1.00000000019001, 76.1800917294715, -86.5053203294168, 24.0140982408309, -1.23173957245015, 0.0012086509738662, -0.000005395239385);
+  if z < 0.5 then
+    return ln(Pi / sin(Pi * z)) - ln_gamma(1.0 - z)
+  else
+    z -:= 1.0;
+    b := z + 5.5;
+    a := lz[1];
+    for i from 2 to 7 do
+      a +:= lz[i] / (z + i - 1)
+    od;
+    return (ln(sqrt(2 * Pi)) + ln(a) - b) + ln(b) * (z + 0.5)
+  fi
+end;
+
+proc gamma(z :: number) :: number is
+  return exp(ln_gamma(z));
+end;
+
+scope
+  for x from 0.1 to 2.05 by 0.1 do
+    printf("%3.1f\t%15.12f\n", x, gamma(x))
+  od
+epocs