biwtInternalFunctions | R Documentation |
Tukey's biweight gives robust estimates of a p-dimensional mean vector and covariance matrix. These functions are used internally within the biweight estimation function.
chi.int2.p(p, a, c1) chi.int2(p,a,c1) chi.int.p(p,a,c1) chi.int(p,a,c1) erho.bw.p(p,c1) erho.bw(p,c1) ksolve(d,p,c1,b0) psibw(x,c1) rhobw(x,c1) vbw(x,c1) wtbw(x,c1) rejpt.bw(p,r) vect2diss(v)
p |
the dimension of the data (should be two if computing correlations. Unlike Pearson correlation, pairwise correlations will not be the same if computed on the entire data set as compared to one pair at a time.) |
a |
degrees of freedom for the chi square distribution |
c1 |
cutoff value at which the biweight function gives zero weight to any data point |
d |
vector of distances from each data point to mean vector |
b0 |
expected value of the ρ function for the biweight estimator (under normality) |
x |
value at which the biweight (ρ, ψ, v, w) should be evaluated |
r |
breakdown (k/n where k is the largest number of observations that can be replaced with arbitrarily large values while keeping the estimates bounded) |
v |
a vector (presumably from |
These functions are used internally for the biwt.est
and biwt.cor
functions in the biwt
package.
The following functions evaluate partial integrals of the χ^2 distribution: chi.int
, chi.in2
, chi.int.p
, chi.int2.p
.
The following functions evaluate the biweight functions: psibw
, rhobw
, wbw
, vbw
.
The following functions caluclate the expected value of the ρ function under the assumption of normally distribued data: erho.bw
, erho.bw.p
.
The function ksolve
keeps the estimates from imploding by setting the mean value of ρ equal to its expected value under normality.
The function rejpt.bw
gives the asymptotic rejection point.
The function vect2diss
converts a vector consisting of a lower triangle of a matrix into a symmetric dissimilarity or similarity matrix. The function is similar to dissmatrix
in the hopach
package, except that vect2diss
fills in the lower triangle first while dissmatrix
fills in the upper triangle first.
Jo Hardin jo.hardin@pomona.edu
Hardin, J., Mitani, A., Hicks, L., VanKoten, B.; A Robust Measure of Correlation Between Two Genes on a Microarray, BMC Bioinformatics, 8:220; 2007.
biwt.est
, biwt.cor
## These are not user level functions ## See examples for biwt.est or biwt.cor ## ?biwt.est ## ?biwt.cor
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