o.flow			package: none			R Documentation

Shows if the ocurrence of a phenomenon on the surface of a cylinder is related to the velocity of water (or another fluid) flowing around it, using the angle where the phenomenon occurs. 


Description:

First, the function does a Rao's Test for Homogeneity, to determine if there is directionality. This test is based on the idea that if the underlying distribution is uniform, successive observations should be approximately evenly spaced. Second, the function realizes a circular linear model (lm.circular(), "Circular" package), between the angles and the expected velocity of the fluid at each angle "uθ", given by the following formula=

uθ= 2U sin θ

Where "U" is the velocity of an uniform streamed fluid, and "θ" is the angle in degrees, from the stagnation point (0 degrees). The velocity is inversely related to fluid tension on the surface.
This function also compares the frecuency of the observed angles with the expected frecuency (Watson's Two Sample Test of Homogeneity ("circular" package)), if the phenomenon is expected to occurr at high or low fluid velocity. Finally, it makes a rose diagram showing the observed and expected frecuencies.

Usage:

o.flow(x,z) 

Arguments:

x	List of angles from an observed event on a cylinder surface.
z	Shows if the phenomenon is expected to occur in high or low velocity.

Details

Value of the argument "z" is either "1" for expected frecuency at high velocity, or "2" for expected frecuency at low velocity. 

Value


NULL

Warning

NULL

Note. 

Requieres the Package 'Circular'

Author:

Andrés Rojas Valle
andresrova@gmail.com

References:
Brennen, C. E. 2006. Internet Book on Fluid Dynamics. http://brennen.caltech.edu/fluidbook/basicfluiddynamics/potentialflow/singularities/cylinder.pdf

 Levitin, D. J. and  G.S. Russell. 1997.  Encyclopedia of Statistical Sciences, Kotz, S. and Read, C. B. [Eds.], New York:  John Wiley & Sons



#Examples: