rwyxz {geostats}

Spurious correlation

Description

Calculate the ‘null correlation’ of ratios, using the the spurious correlation formula of Pearson (1897).

Usage

rwyxz(
  mw,
  mx,
  my,
  mz,
  sw,
  sx,
  sy,
  sz,
  rwx = 0,
  rwy = 0,
  rwz = 0,
  rxy = 0,
  rxz = 0,
  ryz = 0
)

ryxy(mx, my, sx, sy, rxy = 0)

rxzyz(mx, my, mz, sx, sy, sz, rxy = 0, rxz = 0, ryz = 0)

Arguments

mw

the mean of variable w

mx

the mean of variable x

my

the mean of variable y

mz

the mean of variable z

sw

the standard deviation of variable w

sx

the standard deviation of variable x

sy

the standard deviation of variable y

sz

the standard deviation of variable z

rwx

the correlation coefficient between w and x

rwy

the correlation coefficient between w and y

rwz

the correlation coefficient between w and z

rxy

the correlation coefficient between x and y

rxz

the correlation coefficient between x and z

ryz

the correlation coefficient between y and z

Value

the null correlation coefficient

References

Pearson, K. “Mathematical contributions to the theory of evolution. – on a form of spurious correlation which may arise when indices are used in the measurement of organs.” Proceedings of the Royal Society of London 60.359-367 (1897): 489-498.

Examples

rxzyz(mx=100,my=100,mz=100,sx=1,sy=1,sz=10)