classo: Fits regularization paths for lasso penalized learning...

Description Usage Arguments

Description

Fits regularization paths for linear constraints lasso penalized learning problems at a sequence of regularization parameters lambda.

Usage

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classo(y, Z, Zc = NULL, intercept = TRUE, pf = rep(1, times = p),
  lam = NULL, nlam = 100, lambda.factor = ifelse(n < p, 0.05, 0.001),
  dfmax = p, pfmax = min(dfmax * 1.5, p), u = 1, mu_ratio = 1.01,
  tol = 1e-10, outer_maxiter = 3e+08, outer_eps = 1e-08,
  inner_maxiter = 1e+06, inner_eps = 1e-08, A = rep(1, times = p),
  b = 0, beta.ini)

Arguments

y

a vector of response variable with length n.

Z

a n*p matrix after taking log transformation on compositional data.

Zc

a design matrix of other covariates considered. Default is NULL.

intercept

Whether to include intercept in the model. Default is TRUE.

pf

penalty factor, a vector in length of p. Separate penalty weights can be applied to each coefficience β for composition variates to allow differential shrinkage. Can be 0 for some β's, which implies no shrinkage, and results in that composition always being included in the model. Default value for each entry is the 1.

lam

a user supplied lambda sequence. Typically, by leaving this option unspecified users can have the program compute its own lam sequence based on nlam and lambda.factor If lam is provided but a scaler, lam sequence is also created starting from lam. Supplying a value of lambda overrides this. It is better to supply a decreasing sequence of lambda values, if not, the program will sort user-defined lambda sequence in decreasing order automatically.

nlam

the length of lam sequence - default is 100.

lambda.factor

the factor for getting the minimal lambda in lam sequence, where min(lam) = lambda.factor * max(lam). max(lam) is the smallest value of lam for which all penalized group are zero's. The default depends on the relationship between n and p1 If n >= p1 the default is 0.001, close to zero. If n < p1, the default is 0.05. A very small value of lambda.factor will lead to a saturated fit. It takes no effect if there is user-defined lambda sequence.

dfmax

limit the maximum number of groups in the model. Useful for very large p, if a partial path is desired - default is p.

pfmax

limit the maximum number of groups ever to be nonzero. For example once a group enters the model along the path, no matter how many times it exits or re-enters model through the path, it will be counted only once. Default is min(dfmax*1.5, p).

u

u is the inital value for penalty parameter of augmented Lanrange method adopted in outer loop - default value is 1.

mu_ratio

mu_ratio is the increasing ratio for u - default value is 1.01. Inital values for scaled Lagrange multipliers are set as 0's. If mu_ratio < 1, there is no linear constraints included. Group lasso coefficients are estimated.

tol

tolerance for vectors beta'ss to be considered as none zero's. For example, coefficient β_j for group j, if max(abs(β_j)) < tol, set β_j as 0's. Default value is 0.

outer_maxiter

outer_maxiter is the maximun munber of loops allowed for Augmented Lanrange method; and outer_eps is the convergence termination tolerance.

outer_eps

outer_maxiter is the maximun munber of loops allowed for Augmented Lanrange method; and outer_eps is the convergence termination tolerance.

inner_maxiter

inner_maxiter is the maximun munber of loops allowed for blockwise-GMD; and inner_eps is the convergence termination tolerance.

inner_eps

inner_maxiter is the maximun munber of loops allowed for blockwise-GMD; and inner_eps is the convergence termination tolerance.

A, b

linear equality constraints Aβ_p = b, where b is a scaler, and A is a vector with length p. Default values, b is a vector of 0 and A = rep(1, times = p).

beta.ini

inital value of beta


Zhe-Research/compReg documentation built on May 28, 2019, 8:38 a.m.