Investment Studio > Expressions > Functions > Statistical > NORMSDIST

float normsdist(float x, boolean cumulative = TRUE)

Returns the standard normal probability function. Equivalent to normdist(x, 0, 1, cumulative).

x is the point of evaluation.

If cumulative = TRUE, the CDF (Cumulative Distribution Function) is returned (equal to the probability that x is >= a stochastic variable with standard normal distribution); otherwise, the PDF (Probability Density Function) is returned. If omitted, cumulative defaults to TRUE.

Mathematically, the standard normal PDF is

  -x2 / 2
  e
f(x) =  ¾¾¾¾
  (2p)1/2

and the CDF is

  x  
F(x) =  ó f(u) du
ô
õ
  -¥  

See normdist for more information on the normal distribution.

Example

=normsdist(1, TRUE)

returns 0.841344746050147;

=normsdist(1, FALSE)

returns 0.241970724519143.

See also normdist, norminv, normsinv, standardize, ztest.