signtest
              Test for median.
Perform a signtest of the null hypothesis that x is from a distribution that has a zero median. x must be a vector.
If the second argument m is a scalar, the null hypothesis is that X has median m.
 If the second argument y is a vector, the null hypothesis is that
 the distribution of x - y has zero median.
 The argument "alpha" can be used to specify the significance level
 of the test (the default value is 0.05).  The string
 argument "tail", can be used to select the desired alternative
 hypotheses.  If "tail" is "both" (default) the null is
 tested against the two-sided alternative median (x) != m.
 If "tail" is "right" the one-sided
 alternative median (x) > m is considered.
 Similarly for "left", the one-sided alternative median
 (x) < m is considered.
 When "method" is "exact" the p-value is computed using an
 exact method.  When "method" is "approximate" a normal
 approximation is used for the test statistic. When "method" is not
 defined as an optional input argument, then for length (x) < 100
 the "exact" method is computed, otherwise the "approximate"
 method is used.
The p-value of the test is returned in pval. If h is 0 the null hypothesis is accepted, if it is 1 the null hypothesis is rejected. stats is a structure containing the value of the test statistic (sign) and the value of the z statistic (zval) (only computed when the ’method’ is ’approximate’.
Source Code: signtest