The tcdf function calculates the student's t cumulative distribution function (CDF).

Synopsis

tcdf(x,degrees_of_freedom)

Summary

Student's t-CDF returns the probability that a single observation from the t distribution with ν degrees of freedom will fall in the interval [−∞, x):

Example

Create a 1-dimensional array of size 10 and fill it with values from 0.5 to 9.5:
```
AFL% store(build(<x:double>[i=0:9], i+1/2.0), t_array);
```

Apply the tcdf function to the attribute x for four degrees of freedom:

AFL% apply(t_array, t_cdf, tcdf(x, 4));

The output is:

{i} x,t_cdf
{0} 0.5,0.678335
{1} 1.5,0.896
{2} 2.5,0.966617
{3} 3.5,0.987552
{4} 4.5,0.994589
{5} 5.5,0.997336
{6} 6.5,0.998555
{7} 7.5,0.999155
{8} 8.5,0.999475
{9} 9.5,0.999657

Remove the example array:
```
AFL% remove(t_array);
```

Inverse

itcdf: Inverse t-Student CDF