normcdf
statistics: p = normcdf (x)
statistics: p = normcdf (x, mu)
statistics: p = normcdf (x, mu, sigma)
statistics: p = normcdf (…, "upper"
)
statistics: [p, plo, pup] = normcdf (x, mu, sigma, pcov)
statistics: [p, plo, pup] = normcdf (x, mu, sigma, pcov, alpha)
statistics: [p, plo, pup] = normcdf (…, "upper"
)
Normal cumulative distribution function (CDF).
For each element of x, compute the cumulative distribution function (CDF) of the normal distribution with mean mu and standard deviation sigma. The size of p is the common size of x, mu and sigma. A scalar input functions as a constant matrix of the same size as the other inputs.
Default values are mu = 0, sigma = 1.
When called with three output arguments, i.e. [p, plo,
pup]
, normcdf
computes the confidence bounds for p when
the input parameters mu and sigma are estimates. In such case,
pcov, a matrix containing the covariance matrix of the
estimated parameters, is necessary. Optionally, alpha, which has a
default value of 0.05, specifies the 100 * (1 - alpha)
percent
confidence bounds. plo and pup are arrays of the same size as
p containing the lower and upper confidence bounds.
[…] = normcdf (…, "upper")
computes the upper tail
probability of the normal distribution with parameters mu and
sigma, at the values in x. This can be used to compute a
right-tailed p-value. To compute a two-tailed p-value, use
2 * normcdf (-abs (x), mu, sigma)
.
Further information about the normal distribution can be found at https://en.wikipedia.org/wiki/Normal_distribution
See also: norminv, normpdf, normrnd, normfit, normlike, normstat
Source Code: normcdf
## Plot various CDFs from the normal distribution x = -5:0.01:5; p1 = normcdf (x, 0, 0.5); p2 = normcdf (x, 0, 1); p3 = normcdf (x, 0, 2); p4 = normcdf (x, -2, 0.8); plot (x, p1, "-b", x, p2, "-g", x, p3, "-r", x, p4, "-c") grid on xlim ([-5, 5]) legend ({"μ = 0, σ = 0.5", "μ = 0, σ = 1", ... "μ = 0, σ = 2", "μ = -2, σ = 0.8"}, "location", "southeast") title ("Normal CDF") xlabel ("values in x") ylabel ("probability") |