diff --git a/README.Rmd b/README.Rmd index 07d1b01..22a0c06 100644 --- a/README.Rmd +++ b/README.Rmd @@ -38,7 +38,8 @@ $$ Y_i = \beta_0 + \beta_x X_i + \beta_z Z_i + \epsilon_i, \quad \epsilon_i \stackrel{iid}{\sim} N(0, \sigma^2_Y), \quad i=1,\dots,n, $$ -In the context of environmental epidemiology, the covariate $X_i$ can be an exposure to air pollution of subject $i$ at different locations, $Z_i$ can be demographic information, and $Y_i$ can be the associated health outcome. Since exposure $X_i$, $i=1,\dots,n$ are not directly measured at health subject locations but are predicted from air pollution monitoring station locations, this induces spatially correlated measurement error in $X_i$. Also, the uncertainty information should be taken account, which depends on the proximity of the monitoring station to the subject location. One way to incorporate this information is to use a multivariate normal prior on the covariate $(X_1,\dots,X_n)$, +In the context of environmental epidemiology, the covariate $X_i$ can be an exposure to air pollution of subject $i$ at different locations, $Z_i$ can be demographic information, and $Y_i$ can be the associated health outcome. Since exposure $X_i$, $i=1,\dots,n$ are not directly measured at health subject locations but are predicted from air pollution monitoring station locations, this induces spatially correlated measurement error in $X_i$. Also, the uncertainty information should be taken account, which depends on the proximity of the monitoring station to the subject location. One way to incorporate this information is to use a multivariate normal (MVN) prior on a covariate $(X_1,\dots,X_n)$ for all subjects, + $$ (X_1,\dots,X_n)\sim \mathrm{N}_n(\mathbf{m}, \mathbf{Q}^{-1}), $$ @@ -62,9 +63,9 @@ devtools::install_github("changwoo-lee/bspme") | Function | Description | | ---------------------- | -------------------------------------------------------------------------| -| `blinreg_me()` | Bayesian normal linear regression models with (spatially) correlated measurement errors | -| `blogireg_me()` | Bayesian logistic regression models with (spatially) correlated measurement errors | -| `vecchia_cov()` | Perform Vecchia approximation given a MVN covariance matrix | +| `blinreg_me()` | Bayesian normal linear regression models with a MVN prior for measurement errors | +| `blogireg_me()` | Bayesian logistic regression models with a MVN prior for measurement errors | +| `vecchia_cov()` | Perform the Vecchia approximation given a MVN covariance matrix | diff --git a/README.md b/README.md index cbbe353..0b2eabd 100644 --- a/README.md +++ b/README.md @@ -39,8 +39,10 @@ pollution monitoring station locations, this induces spatially correlated measurement error in $X_i$. Also, the uncertainty information should be taken account, which depends on the proximity of the monitoring station to the subject location. One way to incorporate this -information is to use a multivariate normal prior on the covariate -$(X_1,\dots,X_n)$, $$ +information is to use a multivariate normal (MVN) prior on a covariate +$(X_1,\dots,X_n)$ for all subjects, + +$$ (X_1,\dots,X_n)\sim \mathrm{N}_n(\mathbf{m}, \mathbf{Q}^{-1}), $$ with some mean $\mathbf{m}$ and precision (inverse covariance) matrix $\mathbf{Q}$, referred as a MVN prior approach. @@ -70,11 +72,11 @@ devtools::install_github("changwoo-lee/bspme") ## Functionality -| Function | Description | -|-----------------|-----------------------------------------------------------------------------------------| -| `blinreg_me()` | Bayesian normal linear regression models with (spatially) correlated measurement errors | -| `blogireg_me()` | Bayesian logistic regression models with (spatially) correlated measurement errors | -| `vecchia_cov()` | Perform Vecchia approximation given a MVN covariance matrix | +| Function | Description | +|-----------------|----------------------------------------------------------------------------------| +| `blinreg_me()` | Bayesian normal linear regression models with a MVN prior for measurement errors | +| `blogireg_me()` | Bayesian logistic regression models with a MVN prior for measurement errors | +| `vecchia_cov()` | Perform the Vecchia approximation given a MVN covariance matrix | ## datasets