The velocity components and in the laboratory coordinates x and y can be calculated from the velocity in the wire coordinate using an appropriate geometrical transformation, leading to:

	(23)
	(24)

The digitization of the hotwire signal results in N evenly distributed and statistically independent samples that, to a first approximation, can be taken as statistically stationary. The mean value of the velocities and can be evaluated as the ensemble average of the velocity signals and i.e.

	(25)
	(26)

Subsequently, the velocity fluctuations, and are calculated by subtracting the mean component of velocity from the velocity signals and . Hence

	(27)
	(28)

The root mean square components of velocities, and the Reynolds shear stress have been evaluated as:

	(29)
	(30)
	(31)

Here, the measurements from the two wires of the probe are taken to be simultaneous. This assumption neglects the small time lag introduced during data transfer in the A/D card.