| Type: | Package | 
| Title: | ACSS, Corresponding INSS, and GLP Algorithms | 
| Version: | 1.0.0.2 | 
| Date: | 2025-10-10 | 
| Description: | Allow user to run the Adaptive Correlated Spike and Slab (ACSS) algorithm, corresponding INdependent Spike and Slab (INSS) algorithm, and Giannone, Lenza and Primiceri (GLP) algorithm with adaptive burn-in. All of the three algorithms are used to fit high dimensional data set with either sparse structure, or dense structure with smaller contributions from all predictors. The state-of-the-art GLP algorithm is in Giannone, D., Lenza, M., & Primiceri, G. E. (2021, ISBN:978-92-899-4542-4) "Economic predictions with big data: The illusion of sparsity". The two new algorithms, ACSS algorithm and INSS algorithm, and the discussion on their performance can be seen in Yang, Z., Khare, K., & Michailidis, G. (2024, submitted to Journal of Business & Economic Statistics) "Bayesian methodology for adaptive sparsity and shrinkage in regression". | 
| License: | GPL-3 | 
| Encoding: | UTF-8 | 
| Imports: | stats, HDCI (≥ 1.0-2), MASS (≥ 7.3-60), extraDistr (≥ 1.4-4) | 
| LinkingTo: | Rcpp (≥ 1.0.11), RcppArmadillo (≥ 0.12.6.3.0) | 
| RoxygenNote: | 7.3.3 | 
| Depends: | R (≥ 3.0.2) | 
| LazyData: | true | 
| NeedsCompilation: | yes | 
| Packaged: | 2025-10-11 00:17:38 UTC; yangt | 
| Author: | Ziqian Yang [cre, aut], Kshitij Khare [aut], George Michailidis [aut] | 
| Maintainer: | Ziqian Yang <zi.yang@ufl.edu> | 
| Repository: | CRAN | 
| Date/Publication: | 2025-10-11 04:40:02 UTC | 
ACSS algorithm
Description
Adaptive Correlated Spike and Slab (ACSS) algorithm with/without adaptive burn-in Gibbs sampler. See paper of Yang, Z., Khare, K., & Michailidis, G. (2024) for details.
Usage
ACSS_gs(
  Y,
  X,
  para = c("1sqrtp", "11", "4sqrtp", "Unif", "customize"),
  a = 1,
  b = 1,
  c = 1,
  s = NA,
  Max_burnin = 10,
  nmc = 5000,
  adaptive_burn_in = TRUE
)
Arguments
| Y | A (centered) vector. | 
| X | A (centered in column) matrix. | 
| para | Parameter pre-set. Options include "1sqrtp" (default), "11", "4sqrtp", "Unif", and "customize". See details below. 
 If no parameter pre-set is provided, the default "1sqrtp" will be used. | 
| a | shape parameter for marginal of q; default=1. | 
| b | shape parameter for marginal of q; default=1. | 
| c | shape parameter for marginal of lambda^2; larger c introduce more shrinkage and stronger correlation. default=1. | 
| s | scale (inversed) parameter for marginal of lambda^2; larger s introduce more shrinkage; default=sqrt(p). | 
| Max_burnin | Maximum burn-in (in 100 steps) for adaptive burn-in Gibbs sampler. Minimum value is 10, corresponding to 1000 hard burn-insteps. Default=10. | 
| nmc | Number of MCMC samples. Default=5000. | 
| adaptive_burn_in | Logical. If TRUE, use adaptive burn-in Gibbs sampler; If false, use fixed burn-in with burn-in = Max_burnin. Default=TRUE. | 
Value
A list with betahat: predicted beta hat from majority voting, and Gibbs_res: 5000 samples of beta, q and lambda^2 from Gibbs sampler.
Examples
## A toy example is given below to save time. The full example can be run to get better results
## by letting nmc=5000 (default).
n = 30;
p = n;
beta1 = rep(0.1, p);
beta2 = c(rep(0.2, p / 2), rep(0, p / 2));
beta3 = c(rep(0.15, 3 * p / 4), rep(0, ceiling(p / 4)));
beta4 = c(rep(1, p / 4), rep(0, ceiling(3 * p / 4)));
beta5 = c(rep(3, ceiling(p / 20)), rep(0 , 19 * p / 20));
betas = list(beta1, beta3, beta2, beta4, beta5);
set.seed(123);
X = matrix(rnorm(n * p), n, p);
Y = c(X %*% betas[[1]] + rnorm(n));
## A toy example with p=30, total Gibbs steps=1100, takes ~0.6s
system.time({mod = ACSS_gs(Y, X, para = "1sqrtp", nmc = 100);})
mod$beta; ## estimated beta after the Majority voting
hist(mod$Gibbs_res$betamat[1,]); ## histogram of the beta_1
hist(mod$Gibbs_res$q); ## histogram of the q
hist(log(mod$Gibbs_res$lambdasq)); ## histogram of the log(lambda^2)
hist(mod$Gibbs_res$R_2); ## histogram of the R^2 for each iteration in Gibbs sampler
plot(mod$Gibbs_res$q, type = "l"); ## trace plot of the q
## joint posterior of model density and shrinkage
plot(log(mod$Gibbs_res$q / (1 - mod$Gibbs_res$q)), -log(mod$Gibbs_res$lambdasq),
    xlab = "logit(q)", ylab = "-log(lambda^2)",
    main = "Joint Posterior of Model Density and Shrinkage"); 
Economic data from the GLP paper
Description
A list contains the five data set used in the paper of Giannone, Lenza, and Primiceri (2021). Contains the following data sets: Macro1, Macro2, Micro1, Micro2, and Finance1
Usage
Econ_data
Format
## 'Econ_data' A list contains the five lists, as the 5 data sets
- Macro1
- A list with a vector and a data frame, 'Y' and 'X'. 'Y' is the response vector, with 659 observations in it. 'X' is the data frame contains all predictors, with n=659, p=130. It have the structure of time series data. 
- Macro2
- A list with a vector and a data frame, 'Y' and 'X'. 'Y' is the response vector, with 90 observations in it. 'X' is the data frame contains all predictors, with n=90, p=69. It have the structure of sectional data. 
- Micro1
- A list with a vector and a data frame, 'Y' and 'X'. 'Y' is the response vector, with 576 observations in it. 'X' is the data frame contains all predictors, with n=576, p=285. It have the structure of panel data with 48 units on 12 time points. 
- Micro2
- A list with a vector and a data frame, 'Y' and 'X'. 'Y' is the response vector, with 312 observations in it. 'X' is the data frame contains all predictors, with n=312, p=138. It have the structure of panel data with 12 units on 26 time points. 
- Finance1
- A list with a vector and a data frame, 'Y' and 'X'. 'Y' is the response vector, with 68 observations in it. 'X' is the data frame contains all predictors, with n=68, p=16. It have the structure of time series data. 
Source
<https://www.econometricsociety.org/publications/econometrica/2021/09/01/economic-predictions-big-data-illusion-sparsity/supp/17842_Data_and_Programs.zip>
<https://research.stlouisfed.org/econ/mccracken/fred-databases/>
GLP algorithm
Description
Giannone, Lenza and Primiceri (GLP) algorithm with/without adaptive burn-in Gibbs sampler. See paper Giannone, D., Lenza, M., & Primiceri, G. E. (2021) and Yang, Z., Khare, K., & Michailidis, G. (2024) for details.
Most of the codes are from https://github.com/bfava/IllusionOfIllusion with our modification to make it have adaptive burn-in Gibbs sampler, and some debugs.
Usage
GLP_gs(
  Y,
  X,
  a = 1,
  b = 1,
  A = 1,
  B = 1,
  Max_burnin = 10,
  nmc = 5000,
  adaptive_burn_in = TRUE
)
Arguments
| Y | A (centered) vector. | 
| X | A (centered in column) matrix. | 
| a | shape parameter for marginal of q; default=1. | 
| b | shape parameter for marginal of q; default=1. | 
| A | shape parameter for marginal of R^2; default=1. | 
| B | shape parameter for marginal of R^2; default=1. | 
| Max_burnin | Maximum burn-in (in 100 steps) for adaptive burn-in Gibbs sampler. Minimum value is 10, corresponding to 1000 hard burn-insteps. Default=10. | 
| nmc | Number of MCMC samples. Default=5000. | 
| adaptive_burn_in | Logical. If TRUE, use adaptive burn-in Gibbs sampler; If false, use fixed burn-in with burn-in = Max_burnin. Default=TRUE. | 
Value
A list with betahat: predicted beta hat from majority voting, and Gibbs_res: 5000 samples of beta, q and lambda^2 from Gibbs sampler.
Examples
## A toy example is given below to save your time, which will still take ~10s. 
## The full example can be run to get BETTER results, which will take more than 80s, 
## by letting nmc=5000 (default).
n = 30;
p = n;
beta1 = rep(0.1, p);
beta2 = c(rep(0.2, p / 2), rep(0, p / 2));
beta3 = c(rep(0.15, 3 * p / 4), rep(0, ceiling(p / 4)));
beta4 = c(rep(1, p / 4), rep(0, ceiling(3 * p / 4)));
beta5 = c(rep(3, ceiling(p / 20)), rep(0 , 19 * p / 20));
betas = list(beta1, beta3, beta2, beta4, beta5);
set.seed(123);
X = matrix(rnorm(n * p), n, p);
Y = c(X %*% betas[[1]] + rnorm(n));
## A toy example with p=30, total Gibbs steps=1100
system.time({mod = GLP_gs(Y, X, nmc = 100);})
mod$beta; ## estimated beta after the Majority voting
hist(mod$Gibbs_res$betamat[1,]); ## histogram of the beta_1
hist(mod$Gibbs_res$q); ## histogram of the q
hist(log(mod$Gibbs_res$lambdasq)); ## histogram of the log(lambda^2)
hist(mod$Gibbs_res$R_2); ## histogram of the R^2 for each iteration in Gibbs sampler
plot(mod$Gibbs_res$q, type = "l"); ## trace plot of the q
## joint posterior of model density and shrinkage
plot(log(mod$Gibbs_res$q / (1 - mod$Gibbs_res$q)), -log(mod$Gibbs_res$lambdasq),
    xlab = "logit(q)", ylab = "-log(lambda^2)",
    main = "Joint Posterior of Model Density and Shrinkage"); 
INSS algorithm
Description
INdependent Spike and Slab (INSS) algorithm with/without adaptive burn-in Gibbs sampler. See paper of Yang, Z., Khare, K., & Michailidis, G. (2024) for details.
Usage
INSS_gs(
  Y,
  X,
  para = c("1sqrtp", "11", "4sqrtp", "Unif", "customize"),
  a = 1,
  b = 1,
  c = 1,
  s = NA,
  Max_burnin = 10,
  nmc = 5000,
  adaptive_burn_in = TRUE
)
Arguments
| Y | A (centered) vector. | 
| X | A (centered in column) matrix. | 
| para | Parameter pre-set. Options include "1sqrtp" (default), "11", "4sqrtp", "Unif", and "customize". See details below. 
 If no parameter pre-set is provided, the default "1sqrtp" will be used. | 
| a | shape parameter for marginal of q; default=1. | 
| b | shape parameter for marginal of q; default=1. | 
| c | shape parameter for marginal of lambda^2; larger c introduce more shrinkage and stronger correlation. default=1. | 
| s | scale (inversed) parameter for marginal of lambda^2; larger s introduce more shrinkage; default=sqrt(p). | 
| Max_burnin | Maximum burn-in (in 100 steps) for adaptive burn-in Gibbs sampler. Minimum value is 10, corresponding to 1000 hard burn-insteps. Default=10. | 
| nmc | Number of MCMC samples. Default=5000. | 
| adaptive_burn_in | Logical. If TRUE, use adaptive burn-in Gibbs sampler; If false, use fixed burn-in with burn-in = Max_burnin. Default=TRUE. | 
Value
A list with betahat: predicted beta hat from majority voting, and Gibbs_res: 5000 samples of beta, q and lambda^2 from Gibbs sampler.
Examples
## A toy example is given below to save time. The full example can be run to get better results
## by letting nmc=5000 (default).
n = 30;
p = n;
beta1 = rep(0.1, p);
beta2 = c(rep(0.2, p / 2), rep(0, p / 2));
beta3 = c(rep(0.15, 3 * p / 4), rep(0, ceiling(p / 4)));
beta4 = c(rep(1, p / 4), rep(0, ceiling(3 * p / 4)));
beta5 = c(rep(3, ceiling(p / 20)), rep(0 , 19 * p / 20));
betas = list(beta1, beta3, beta2, beta4, beta5);
set.seed(123);
X = matrix(rnorm(n * p), n, p);
Y = c(X %*% betas[[1]] + rnorm(n));
## A toy example with p=30, total Gibbs steps=1100, takes ~0.6s
system.time({mod = INSS_gs(Y, X, para = "1sqrtp", nmc = 100);})
mod$beta; ## estimated beta after the Majority voting
hist(mod$Gibbs_res$betamat[1,]); ## histogram of the beta_1
hist(mod$Gibbs_res$q); ## histogram of the q
hist(log(mod$Gibbs_res$lambdasq)); ## histogram of the log(lambda^2)
hist(mod$Gibbs_res$R_2); ## histogram of the R^2 for each iteration in Gibbs sampler
plot(mod$Gibbs_res$q, type = "l"); ## trace plot of the q
## joint posterior of model density and shrinkage
plot(log(mod$Gibbs_res$q / (1 - mod$Gibbs_res$q)), -log(mod$Gibbs_res$lambdasq),
    xlab = "logit(q)", ylab = "-log(lambda^2)",
    main = "Joint Posterior of Model Density and Shrinkage");