| Type: | Package | 
| Title: | High-Dimensional Covariate-Augmented Overdispersed Poisson Factor Model | 
| Version: | 1.3 | 
| Date: | 2025-03-27 | 
| Author: | Wei Liu [aut, cre], Qingzhi Zhong [aut] | 
| Maintainer: | Wei Liu <liuweideng@gmail.com> | 
| Description: | A covariate-augmented overdispersed Poisson factor model is proposed to jointly perform a high-dimensional Poisson factor analysis and estimate a large coefficient matrix for overdispersed count data. More details can be referred to Liu et al. (2024) <doi:10.1093/biomtc/ujae031>. | 
| License: | GPL-3 | 
| Depends: | irlba, R (≥ 3.5.0) | 
| Imports: | MASS, stats, Rcpp (≥ 1.0.10) | 
| URL: | https://github.com/feiyoung/COAP | 
| BugReports: | https://github.com/feiyoung/COAP/issues | 
| Suggests: | knitr, rmarkdown | 
| LinkingTo: | Rcpp, RcppArmadillo | 
| VignetteBuilder: | knitr | 
| Encoding: | UTF-8 | 
| RoxygenNote: | 7.1.2 | 
| NeedsCompilation: | yes | 
| Packaged: | 2025-03-27 09:49:55 UTC; Liuxianju | 
| Repository: | CRAN | 
| Date/Publication: | 2025-03-27 11:30:02 UTC | 
Fit the COAP model
Description
Fit the covariate-augmented overdispersed Poisson factor model
Usage
RR_COAP(
  X_count,
  multiFac = rep(1, nrow(X_count)),
  Z = matrix(1, nrow(X_count), 1),
  rank_use = 5,
  q = 15,
  epsELBO = 1e-05,
  maxIter = 30,
  verbose = TRUE,
  joint_opt_beta = FALSE,
  fast_svd = TRUE
)
Arguments
| X_count | a count matrix, the observed count matrix. | 
| multiFac | an optional vector, the normalization factor for each unit; default as full-one vector. | 
| Z | an optional matrix, the covariate matrix; default as a full-one column vector if there is no additional covariates. | 
| rank_use | an optional integer, specify the rank of the regression coefficient matrix; default as 5. | 
| q | an optional string, specify the number of factors; default as 15. | 
| epsELBO | an optional positive vlaue, tolerance of relative variation rate of the envidence lower bound value, defualt as '1e-5'. | 
| maxIter | the maximum iteration of the VEM algorithm. The default is 30. | 
| verbose | a logical value, whether output the information in iteration. | 
| joint_opt_beta | a logical value, whether use the joint optimization method to update bbeta. The default is  | 
| fast_svd | a logical value, whether use the fast SVD algorithm in the update of bbeta; default is  | 
Details
None
Value
return a list including the following components: (1) H, the predicted factor matrix; (2) B, the estimated loading matrix; (3) bbeta, the estimated low-rank large coefficient matrix; (4) invLambda, the inverse of the estimated variances of error; (5) H0, the factor matrix; (6) ELBO: the ELBO value when algorithm stops; (7) ELBO_seq: the sequence of ELBO values.
References
Liu, W. and Q. Zhong (2024). High-dimensional covariate-augmented overdispersed poisson factor model. arXiv preprint arXiv:2402.15071.
See Also
None
Examples
n <- 300; p <- 100
d <- 20; q <- 6; r <- 3
datlist <- gendata_simu(n=n, p=p, d=20, q=q, rank0=r)
str(datlist)
fitlist <- RR_COAP(X_count=datlist$X, Z = datlist$Z, q=6, rank_use=3)
str(fitlist)
Generate simulated data
Description
Generate simulated data from covariate-augmented Poisson factor models
Usage
gendata_simu(
  seed = 1,
  n = 300,
  p = 50,
  d = 20,
  q = 6,
  rank0 = 3,
  rho = c(1.5, 1),
  sigma2_eps = 0.1,
  seed.beta = 1
)
Arguments
| seed | a postive integer, the random seed for reproducibility of data generation process. | 
| n | a postive integer, specify the sample size. | 
| p | a postive integer, specify the dimension of count variables. | 
| d | a postive integer, specify the dimension of covariate matrix. | 
| q | a postive integer, specify the number of factors. | 
| rank0 | a postive integer, specify the rank of the coefficient matrix. | 
| rho | a numeric vector with length 2 and positive elements, specify the signal strength of regression coefficient and loading matrix, respectively. | 
| sigma2_eps | a positive real, the variance of overdispersion error. | 
| seed.beta | a postive integer, the random seed for reproducibility of data generation process by fixing the regression coefficient matrix beta. | 
Details
None
Value
return a list including the following components: (1) X, the high-dimensional count matrix; (2) Z, the high-dimensional covriate matrix; (3) bbeta0, the low-rank large coefficient matrix; (4) B0, the loading matrix; (5) H0, the factor matrix; (6) rank: the true rank of bbeta0; (7) q: the true number of factors.
References
None
See Also
Examples
n <- 300; p <- 100
d <- 20; q <- 6; r <- 3
datlist <- gendata_simu(n=n, p=p, d=20, q=q, rank0=r)
str(datlist)
Select the parameters in COAP models
Description
Select the number of factors and the rank of coefficient matrix in the covariate-augmented overdispersed Poisson factor model
Usage
selectParams(
  X_count,
  Z,
  multiFac = rep(1, nrow(X_count)),
  q_max = 15,
  r_max = 24,
  threshold = c(0.1, 0.01),
  verbose = TRUE,
  ...
)
Arguments
| X_count | a count matrix, the observed count matrix. | 
| Z | an optional matrix, the covariate matrix; default as a full-one column vector if there is no additional covariates. | 
| multiFac | an optional vector, the normalization factor for each unit; default as full-one vector. | 
| q_max | an optional string, specify the upper bound for the number of factors; default as 15. | 
| r_max | an optional integer, specify the upper bound for the rank of the regression coefficient matrix; default as 24. | 
| threshold | an optional 2-dimensional positive vector, specify the the thresholds that filters the singular values of beta and B, respectively. | 
| verbose | a logical value, whether output the information in iteration. | 
| ... | other arguments passed to the function  | 
Details
The threshold is to filter the singular values with low signal, to assist the identification of underlying model structure.
Value
return a named vector with names 'hr' and 'hq', the estimated rank and number of factors.
References
None
See Also
Examples
n <- 300; p <- 100
d <- 20; q <- 6; r <- 3
datlist <- gendata_simu(seed=30, n=n, p=p, d=20, q=q, rank0=r)
str(datlist)
set.seed(1)
para_vec <- selectParams(X_count=datlist$X, Z = datlist$Z)
print(para_vec)