C++ (Cpp) dlnbet Examples

Example #1

File: cdf.c Project: Johnicholas/simulua

static int cdf_dbeta (lua_State *L) {
  /* stack should contain x, a and b */
  lua_Number x = luaL_checknumber(L, 1);
  lua_Number a = luaL_checknumber(L, 2);
  lua_Number b = luaL_checknumber(L, 3);
  check_beta(L, 1, x, a, b);
  lua_pushnumber(L, (x==0 || x==1) ? 0 :
      exp((a-1)*log(x)+(b-1)*log(1-x)-dlnbet(&a, &b)));
  return 1;
}

Example #2

File: cdf.c Project: Johnicholas/simulua

static int cdf_dnbinom (lua_State *L) {
  /* stack should contain s, xn, pr */
  lua_Number s = luaL_checknumber(L, 1);
  lua_Number xn = luaL_checknumber(L, 2);
  lua_Number pr = luaL_checknumber(L, 3);
  lua_Number d;
  check_nbinom(L, 1, s, xn, pr);
  d = exp(xn*log(pr)+s*log(1-pr)-dlnbet(&s, &xn))/s;
  lua_pushnumber(L, d);
  return 1;
}

Example #3

File: cdf.c Project: Johnicholas/simulua

static int cdf_dt (lua_State *L) {
  /* stack should contain x and df */
  lua_Number x = luaL_checknumber(L, 1);
  lua_Number df = luaL_checknumber(L, 2);
  lua_Number t = 0.5;
  lua_Number d;
  check_t(L, 1, x, df);
  d = df/2;
  d = -dlnbet(&d, &t)-(df+1)/2*log(1+x*x/df);
  d = exp(d)/sqrt(df);
  lua_pushnumber(L, d);
  return 1;
}

Example #4

File: cdf.c Project: Johnicholas/simulua

static int cdf_dbinom (lua_State *L) {
  /* stack should contain s, xn, pr */
  lua_Number s = luaL_checknumber(L, 1);
  lua_Number xn = luaL_checknumber(L, 2);
  lua_Number pr = luaL_checknumber(L, 3);
  lua_Number d;
  check_binom(L, 1, s, xn, pr);
  xn -= s;
  d = s*log(pr)+xn*log(1-pr);
  xn++; s++; /* gamma correction */
  d = exp(d-dlnbet(&xn, &s)-log(xn+s-1));
  lua_pushnumber(L, d);
  return 1;
}

Example #5

File: cdf.c Project: Johnicholas/simulua

static int cdf_df (lua_State *L) {
  /* stack should contain f, dfn, dfd */
  lua_Number f = luaL_checknumber(L, 1);
  lua_Number dfn = luaL_checknumber(L, 2);
  lua_Number dfd = luaL_checknumber(L, 3);
  lua_Number df1, df2, r, d;
  check_f(L, 1, f, dfn, dfd);
  df1 = dfn/2;
  df2 = dfd/2;
  r = dfn/dfd;
  d = df1*log(r)+(df1-1)*log(f);
  d -= (df1+df2)*log(1+r*f);
  d -= dlnbet(&df1, &df2);
  lua_pushnumber(L, exp(d));
  return 1;
}

Example #6

File: cdf.c Project: Johnicholas/simulua

static int cdf_lbeta (lua_State *L) {
  lua_Number a = luaL_checknumber(L, 1);
  lua_Number b = luaL_checknumber(L, 2);
  lua_pushnumber(L, dlnbet(&a, &b));
  return 1;
}

Example #7

File: lcdf.c Project: CAAP/Lua

static int fchoose (lua_Number n, lua_Number k) {
    lua_Number a = n - k + 1;
    lua_Number b = k + 1;
    return -dlnbet(&a, &b) - log(n + 1);
}