The function Perform1SampleTTest returns the probability associated with a 1sample t test (probability which indicates the likelihood that the sample has come from an underlying population having the mean RefMean).
The array data contains the data, the parameter RefMean defines the mean of the population to be compared with. The parameter OneSided has to be TRUE for onesided tests, or FALSE for twosided tests. The function returns additional parameters obtained during the t test calculation:
Mean 
the mean of the sample 
StdDev 
the standard deviation of the sample 
tStatistic 
t statistic 
df 
degrees of freedom 
The function returns the following values:
≥0 ... the pvalue associated with the t statistic
1 ... the array data contains less than 2 data points
2 ... the standard deviation of the sample is zero
