| Type: | Package | 
| Title: | Extended State-Space SIR Models | 
| Version: | 0.4.2 | 
| Description: | An implementation of extended state-space SIR models developed by Song Lab at UM school of Public Health. There are several functions available by 1) including a time-varying transmission modifier, 2) adding a time-dependent quarantine compartment, 3) adding a time-dependent antibody-immunization compartment. Wang L. (2020) <doi:10.6339/JDS.202007_18(3).0003>. | 
| License: | CC BY 4.0 | 
| Encoding: | UTF-8 | 
| Imports: | coda (≥ 0.19.3), chron (≥ 2.3.54), data.table (≥ 1.12.0), ggplot2 (≥ 3.2.1), grDevices (≥ 3.5.2), graphics (≥ 3.5.2), gtools (≥ 3.8.1), scales (≥ 1.1.0), stats (≥ 3.5.2), reshape2 (≥ 1.4.3), rjags (≥ 4.10), utils (≥ 3.5.2) | 
| Depends: | R (≥ 3.5.2) | 
| RoxygenNote: | 7.1.2 | 
| LazyData: | true | 
| Suggests: | testthat (≥ 3.0.0) | 
| Config/testthat/edition: | 3 | 
| NeedsCompilation: | no | 
| Packaged: | 2021-12-06 14:32:50 UTC; mjkle | 
| Author: | Lili Wang [aut], Song Lab [aut] (<http://websites.umich.edu/~songlab/>), Paul Egeler [ctb] (Spectrum Health Office of Research and Education), Michael Kleinsasser [cre] | 
| Maintainer: | Michael Kleinsasser <biostat-cran-manager@umich.edu> | 
| Repository: | CRAN | 
| Date/Publication: | 2021-12-10 13:20:02 UTC | 
Population of US states
Description
Data frame with the populations of each state.
Format
a list with
Province_State State as a character string
N Population of the state
Confirmed COVID-19 cases
Description
Confirmed COVID-19 cases in US states
Format
a list with
Province_State name of the US state
date ... a column for each date
Confirmed COVID-19 deaths
Description
Confirmed COVID-19 deaths in US states
Format
a list with
Province_State name of the US state
date ... a column for each date
Extended state-space SIR with a subset of the population showing antibody positivity
Description
In this function we allow it to characterize time-varying immunization among a subset of the population that have been tested positive in an antibody assessment. We expanded the SIR model by adding a time-varying antibody-positive proportion \alpha_t.
Usage
eSAIR(
  Y,
  R,
  alpha0 = NULL,
  change_time = NULL,
  begin_str = "01/13/2020",
  T_fin = 200,
  nchain = 4,
  nadapt = 10000,
  M = 500,
  thn = 10,
  nburnin = 200,
  dic = FALSE,
  death_in_R = 0.02,
  casename = "eSAIR",
  beta0 = 0.2586,
  gamma0 = 0.0821,
  R0 = beta0/gamma0,
  gamma0_sd = 0.1,
  R0_sd = 1,
  file_add = character(0),
  add_death = FALSE,
  save_files = FALSE,
  save_mcmc = FALSE,
  save_plot_data = FALSE,
  eps = 1e-10
)
Arguments
Y | 
 the time series of daily observed infected compartment proportions.  | 
R | 
 the time series of daily observed removed compartment proportions, including death and recovered.  | 
alpha0 | 
 a vector of values of the dirac delta function   | 
change_time | 
 the change points over time corresponding to   | 
begin_str | 
 the character of starting time, the default is "01/13/2020".  | 
T_fin | 
 the end of follow-up time after the beginning date   | 
nchain | 
 the number of MCMC chains generated by   | 
nadapt | 
 the iteration number of adaptation in the MCMC. We recommend using at least the default value 1e4 to obtained fully adapted chains.  | 
M | 
 the number of draws in each chain, with no thinning. The default is M=5e2 but suggest using 5e5.  | 
thn | 
 the thinning interval between mixing. The total number of draws thus would become   | 
nburnin | 
 the burn-in period. The default is 2e2 but suggest 2e5.  | 
dic | 
 logical, whether compute the DIC (deviance information criterion) for model selection.  | 
death_in_R | 
 the numeric value of average of cumulative deaths in the removed compartments. The default is 0.4 within Hubei and 0.02 outside Hubei.  | 
casename | 
 the string of the job's name. The default is "eSAIR".  | 
beta0 | 
 the hyperparameter of average transmission rate, the default is the one estimated from the SARS first-month outbreak (0.2586).  | 
gamma0 | 
 the hyperparameter of average removed rate, the default is the one estimated from the SARS first-month outbreak (0.0821).  | 
R0 | 
 the hyperparameter of the mean reproduction number R0. The default is thus the ratio of   | 
gamma0_sd | 
 the standard deviation for the prior distrbution of the removed rate   | 
R0_sd | 
 the standard deviation for the prior disbution of R0, the default is 1.  | 
file_add | 
 the string to denote the location of saving output files and tables.  | 
add_death | 
 logical, whether add the approximate death curve to the plot, default is false.  | 
save_files | 
 logical, whether to save plots to file.  | 
save_mcmc | 
 logical, whether save (  | 
save_plot_data | 
 logical, whether save the plotting data or not.  | 
eps | 
 a non-zero controller so that all the input   | 
Value
casename | 
 the predefined   | 
incidence_mean | 
 mean cumulative incidence, the mean prevalence of cumulative confirmed cases at the end of the study.  | 
incidence_ci | 
 2.5%, 50%, and 97.5% quantiles of the incidences.  | 
out_table | 
 summary tables including the posterior mean of the prevalance processes of the 3 states compartments (  | 
plot_infection | 
 plot of summarizing and forecasting for the infection compartment, in which the vertial blue line denotes the last date of data collected (  | 
plot_removed | 
 plot of summarizing and forecasting for the removed compartment with lines similar to those in the   | 
spaghetti_plot | 
 20 randomly selected MCMC draws of the first-order derivative of the posterior prevalence of infection, namely   | 
first_tp_mean | 
 the date t at which   | 
first_tp_mean | 
 the date t at which   | 
first_tp_ci | 
 fwith   | 
second_tp_mean | 
 the date t at which   | 
second_tp_ci | 
 with   | 
dic_val | 
 the output of   | 
gelman_diag_list | 
  Since version 0.3.3, we incorporated Gelman And Rubin's Convergence Diagnostic using   | 
Examples
NI_complete <- c(
  41, 41, 41, 45, 62, 131, 200, 270, 375, 444, 549, 729,
  1052, 1423, 2714, 3554, 4903, 5806, 7153, 9074, 11177,
  13522, 16678, 19665, 22112, 24953, 27100, 29631, 31728, 33366
)
RI_complete <- c(
  1, 1, 7, 10, 14, 20, 25, 31, 34, 45, 55, 71, 94,
  121, 152, 213, 252, 345, 417, 561, 650, 811, 1017,
  1261, 1485, 1917, 2260, 2725, 3284, 3754
)
N <- 58.5e6
R <- RI_complete / N
Y <- NI_complete / N - R # Jan13->Feb 11
change_time <- c("02/08/2020")
alpha0 <- c(0.2) # 20% of the susceptible population were found immunized
res.antibody <- eSAIR(Y, R,
  begin_str = "01/13/2020", death_in_R = 0.4,
  alpha0 = alpha0, change_time = change_time,
  casename = "Hubei_antibody", save_files = TRUE, save_mcmc = FALSE,
  M = 5e2, nburnin = 2e2
)
res.antibody$plot_infection
change_time <- c("01/16/2020")
alpha0 <- c(0.2)
NI_complete2 <- c(41, 45)
RI_complete2 <- c(1, 1)
N2 <- 1E3
res3 <- eSAIR(
  RI_complete2 / N2,
  NI_complete2 / N2,
  begin_str = "01/13/2020",
  T_fin = 4,
  alpha0 = alpha0,
  change_time = change_time,
  dic = FALSE,
  casename = "Hubei_q",
  save_files = FALSE,
  save_mcmc = FALSE,
  save_plot_data = FALSE,
  M = 50,
  nburnin = 1
)
closeAllConnections()
Extended state-space SIR with quarantine
Description
Fit an extended state-space SIR model being reduced by in-home hospitalization.
Usage
qh.eSIR(
  Y,
  R,
  phi0 = NULL,
  change_time = NULL,
  begin_str = "01/13/2020",
  T_fin = 200,
  nchain = 4,
  nadapt = 10000,
  M = 500,
  thn = 10,
  nburnin = 200,
  dic = FALSE,
  death_in_R = 0.02,
  casename = "qh.eSIR",
  beta0 = 0.2586,
  gamma0 = 0.0821,
  R0 = beta0/gamma0,
  gamma0_sd = 0.1,
  R0_sd = 1,
  file_add = character(0),
  add_death = FALSE,
  save_files = FALSE,
  save_mcmc = FALSE,
  save_plot_data = FALSE,
  eps = 1e-10
)
Arguments
Y | 
 the time series of daily observed infected compartment proportions.  | 
R | 
 the time series of daily observed removed compartment proportions, including death and recovered.  | 
phi0 | 
 a vector of values of the dirac delta function   | 
change_time | 
 the change points over time corresponding to   | 
begin_str | 
 the character of starting time, the default is "01/13/2020".  | 
T_fin | 
 the end of follow-up time after the beginning date   | 
nchain | 
 the number of MCMC chains generated by   | 
nadapt | 
 the iteration number of adaptation in the MCMC. We recommend using at least the default value 1e4 to obtained fully adapted chains.  | 
M | 
 the number of draws in each chain, with no thinning. The default is M=5e2 but suggest using 5e5.  | 
thn | 
 the thinning interval between mixing. The total number of draws thus would become   | 
nburnin | 
 the burn-in period. The default is 2e2 but suggest 2e5.  | 
dic | 
 logical, whether compute the DIC (deviance information criterion) for model selection.  | 
death_in_R | 
 the numeric value of average of cumulative deaths in the removed compartments. The default is 0.4 within Hubei and 0.02 outside Hubei.  | 
casename | 
 the string of the job's name. The default is "qh.eSIR".  | 
beta0 | 
 the hyperparameter of average transmission rate, the default is the one estimated from the SARS first-month outbreak (0.2586).  | 
gamma0 | 
 the hyperparameter of average removed rate, the default is the one estimated from the SARS first-month outbreak (0.0821).  | 
R0 | 
 the hyperparameter of the mean reproduction number R0. The default is thus the ratio of   | 
gamma0_sd | 
 the standard deviation for the prior distrbution of the removed rate   | 
R0_sd | 
 the standard deviation for the prior disbution of R0, the default is 1.  | 
file_add | 
 the string to denote the location of saving output files and tables.  | 
add_death | 
 logical, whether add the approximate death curve to the plot, default is false.  | 
save_files | 
 logical, whether to save plots to file.  | 
save_mcmc | 
 logical, whether save (  | 
save_plot_data | 
 logical, whether save the plotting data or not.  | 
eps | 
 a non-zero controller so that all the input   | 
Details
In this function we allow it to characterize time-varying proportions of susceptible due to government-enforced stringent in-home isolation. We expanded the SIR model by adding a quarantine compartment with a time-varying rate of quarantine \phi_t, the chance of a susceptible person  being willing to take in-home isolation at time t.
Value
casename | 
 the predefined   | 
incidence_mean | 
 mean cumulative incidence, the mean prevalence of cumulative confirmed cases at the end of the study.  | 
incidence_ci | 
 2.5%, 50%, and 97.5% quantiles of the incidences.  | 
out_table | 
 summary tables including the posterior mean of the prevalence processes of the 3 states compartments (  | 
plot_infection | 
 plot of summarizing and forecasting for the infection compartment, in which the vertical blue line denotes the last date of data collected (  | 
plot_removed | 
 plot of summarizing and forecasting for the removed compartment with lines similar to those in the   | 
spaghetti_plot | 
 20 randomly selected MCMC draws of the first-order derivative of the posterior prevalence of infection, namely   | 
first_tp_mean | 
 the date t at which   | 
first_tp_mean | 
 the date t at which   | 
first_tp_ci | 
 fwith   | 
second_tp_mean | 
 the date t at which   | 
second_tp_ci | 
 with   | 
dic_val | 
 the output of   | 
gelman_diag_list | 
  Since version 0.3.3, we incorporated Gelman And Rubin's Convergence Diagnostic using   | 
Examples
NI_complete <- c(
  41, 41, 41, 45, 62, 131, 200, 270, 375, 444, 549, 729,
  1052, 1423, 2714, 3554, 4903, 5806, 7153, 9074, 11177,
  13522, 16678, 19665, 22112, 24953, 27100, 29631, 31728, 33366
)
RI_complete <- c(
  1, 1, 7, 10, 14, 20, 25, 31, 34, 45, 55, 71, 94, 121, 152, 213,
  252, 345, 417, 561, 650, 811, 1017, 1261, 1485, 1917, 2260,
  2725, 3284, 3754
)
N <- 58.5e6
R <- RI_complete / N
Y <- NI_complete / N - R # Jan13->Feb 11
change_time <- c("01/23/2020", "02/04/2020", "02/08/2020")
phi0 <- c(0.1, 0.4, 0.4)
res.q <- qh.eSIR(Y, R,
  begin_str = "01/13/2020", death_in_R = 0.4,
  phi0 = phi0, change_time = change_time,
  casename = "Hubei_q", save_files = TRUE, save_mcmc = FALSE,
  M = 5e2, nburnin = 2e2
)
res.q$plot_infection
# res.q$plot_removed
res.noq <- qh.eSIR(Y, R,
  begin_str = "01/13/2020", death_in_R = 0.4,
  T_fin = 200, casename = "Hubei_noq",
  M = 5e2, nburnin = 2e2
)
res.noq$plot_infection
change_time <- c("01/16/2020")
phi0 <- c(0.1)
NI_complete2 <- c(41, 45)
RI_complete2 <- c(1, 1)
N2 <- 1E3
res2 <- qh.eSIR(
  RI_complete2 / N2,
  NI_complete2 / N2,
  begin_str = "01/13/2020",
  T_fin = 4,
  phi0 = phi0,
  change_time = change_time,
  dic = FALSE,
  casename = "Hubei_q",
  save_files = FALSE,
  save_mcmc = FALSE,
  save_plot_data = FALSE,
  M = 50,
  nburnin = 1
)
closeAllConnections()
Confirmed COVID-19 recovered
Description
Confirmed COVID-19 recovered in US states
Format
a list with
Province_State name of the US state
date ... a column for each date
Fit extended state-space SIR model with time-varying transmission rates
Description
Fit extended state-space SIR model with pre-specified changes in the transmission rate, either stepwise or continuous, accommodating time-varying quarantine protocols.
Usage
tvt.eSIR(
  Y,
  R,
  pi0 = NULL,
  change_time = NULL,
  exponential = FALSE,
  lambda0 = NULL,
  begin_str = "01/13/2020",
  T_fin = 200,
  nchain = 4,
  nadapt = 10000,
  M = 500,
  thn = 10,
  nburnin = 200,
  dic = FALSE,
  death_in_R = 0.02,
  beta0 = 0.2586,
  gamma0 = 0.0821,
  R0 = beta0/gamma0,
  gamma0_sd = 0.1,
  R0_sd = 1,
  casename = "tvt.eSIR",
  file_add = character(0),
  add_death = FALSE,
  save_files = FALSE,
  save_mcmc = FALSE,
  save_plot_data = FALSE,
  eps = 1e-10
)
Arguments
Y | 
 the time series of daily observed infected compartment proportions.  | 
R | 
 the time series of daily observed removed compartment proportions, including death and recovered.  | 
pi0 | 
 the time-dependent transmission rate modifier   | 
change_time | 
 the change points over time for step function pi, defalt value is   | 
exponential | 
 logical, whether   | 
lambda0 | 
 the rate of decline in the exponential survival function in   | 
begin_str | 
 the character of starting time, the default is "01/13/2020".  | 
T_fin | 
 the end of follow-up time after the beginning date   | 
nchain | 
 the number of MCMC chains generated by   | 
nadapt | 
 the iteration number of adaptation in the MCMC. We recommend using at least the default value 1e4 to obtained fully adapted chains.  | 
M | 
 the number of draws in each chain, with no thinning. The default is M=5e2 but suggest using 5e5.  | 
thn | 
 the thinning interval between mixing. The total number of draws thus would become   | 
nburnin | 
 the burn-in period. The default is 2e2 but suggest 2e5.  | 
dic | 
 logical, whether compute the DIC (deviance information criterion) for model selection.  | 
death_in_R | 
 the numeric value of average of cumulative deaths in the removed compartments. The default is 0.4 within Hubei and 0.02 outside Hubei.  | 
beta0 | 
 the hyperparameter of average transmission rate, the default is the one estimated from the SARS first-month outbreak (0.2586).  | 
gamma0 | 
 the hyperparameter of average removed rate, the default is the one estimated from the SARS first-month outbreak (0.0821).  | 
R0 | 
 the hyperparameter of the mean reproduction number R0. The default is thus the ratio of   | 
gamma0_sd | 
 the standard deviation for the prior distrbution of the removed rate   | 
R0_sd | 
 the standard deviation for the prior disbution of R0, the default is 1.  | 
casename | 
 the string of the job's name. The default is "tvt.eSIR".  | 
file_add | 
 the string to denote the location of saving output files and tables.  | 
add_death | 
 logical, whether add the approximate death curve to the plot, default is false.  | 
save_files | 
 logical, whether to save plots to file.  | 
save_mcmc | 
 logical, whether save (  | 
save_plot_data | 
 logical, whether save the plotting data or not.  | 
eps | 
 a non-zero controller so that all the input   | 
Details
We fit a state-space model with extended SIR, in which a time-varying transmission rate modifier \pi(t) (between 0 and 1) is introduced to model. This allows us to accommodate quarantine protocol changes and ignored resources of hospitalization. The form of reducing rate may be a step-function with jumps at times of big policy changes or a smooth exponential survival function \exp(-\lambda_0t). The parameters of the function and change points, if any, should be predefined.
Value
casename | 
 the predefined   | 
incidence_mean | 
 mean cumulative incidence, the mean prevalence of cumulative confirmed cases at the end of the study.  | 
incidence_ci | 
 2.5%, 50%, and 97.5% quantiles of the incidences.  | 
out_table | 
 summary tables including the posterior mean of the prevalance processes of the 3 states compartments (  | 
plot_infection | 
 plot of summarizing and forecasting for the infection compartment, in which the vertial blue line denotes the last date of data collected (  | 
plot_removed | 
 plot of summarizing and forecasting for the removed compartment with lines similar to those in the   | 
spaghetti_plot | 
 20 randomly selected MCMC draws of the first-order derivative of the posterior prevalence of infection, namely   | 
first_tp_mean | 
 the date t at which   | 
first_tp_ci | 
 fwith   | 
second_tp_mean | 
 the date t at which   | 
second_tp_ci | 
 with   | 
dic_val | 
 the output of   | 
gelman_diag_list | 
  Since version 0.3.3, we incorporated Gelman And Rubin's Convergence Diagnostic using   | 
Examples
NI_complete <- c(
  41, 41, 41, 45, 62, 131, 200, 270, 375, 444, 549, 729,
  1052, 1423, 2714, 3554, 4903, 5806, 7153, 9074, 11177,
  13522, 16678, 19665, 22112, 24953, 27100, 29631, 31728, 33366
)
RI_complete <- c(
  1, 1, 7, 10, 14, 20, 25, 31, 34, 45, 55, 71, 94, 121, 152, 213,
  252, 345, 417, 561, 650, 811, 1017, 1261, 1485, 1917, 2260,
  2725, 3284, 3754
)
N <- 58.5e6
R <- RI_complete / N
Y <- NI_complete / N - R # Jan13->Feb 11
### Step function of pi(t)
change_time <- c("01/23/2020", "02/04/2020", "02/08/2020")
pi0 <- c(1.0, 0.9, 0.5, 0.1)
res.step <- tvt.eSIR(Y, R,
  begin_str = "01/13/2020", death_in_R = 0.4,
  T_fin = 200, pi0 = pi0, change_time = change_time, dic = TRUE,
  casename = "Hubei_step", save_files = TRUE,
  save_mcmc = FALSE, M = 5e2, nburnin = 2e2
)
res.step$plot_infection
res.step$plot_removed
res.step$dic_val
### continuous exponential function of pi(t)
res.exp <- tvt.eSIR(Y, R,
  begin_str = "01/13/2020", death_in_R = 0.4,
  T_fin = 200, exponential = TRUE, dic = FALSE, lambda0 = 0.05,
  casename = "Hubei_exp", save_files = FALSE, save_mcmc = FALSE,
  M = 5e2, nburnin = 2e2
)
res.exp$plot_infection
# res.exp$plot_removed
### without pi(t), the standard state-space SIR model without intervention
res.nopi <- tvt.eSIR(Y, R,
  begin_str = "01/13/2020", death_in_R = 0.4,
  T_fin = 200, casename = "Hubei_nopi", save_files = FALSE,
  M = 5e2, nburnin = 2e2
)
res.nopi$plot_infection
# res.nopi$plot_removed
change_time <- c("01/18/2020")
pi0<- c(1.0, 0.9)
NI_complete2 <- c(41, 45, 62, 131)
RI_complete2 <- c(1, 1, 7, 10)
N2 <- 1E3
res1 <- tvt.eSIR(
  RI_complete2 / N2,
  (NI_complete2 - RI_complete2) / N2,
  begin_str = "01/10/2020",
  T_fin =10,
  pi0 = pi0,
  change_time = change_time,
  dic = FALSE,
  casename = "Hubei_step",
  save_files = FALSE,
  save_mcmc = FALSE,
  save_plot_data = FALSE,
  M = 50,
  nburnin = 1
)
closeAllConnections()
Fit extended state-space SIR model with time-varying transmission rates
Description
Fit extended state-space SIR model with pre-specified changes in the transmission rate, either stepwise or continuous, accommodating time-varying quarantine protocols.
Usage
tvt.eSIR2(
  Y,
  R,
  pi0 = NULL,
  change_time = NULL,
  exponential = FALSE,
  lambda0 = NULL,
  begin_str = "01/13/2020",
  T_fin = 200,
  nchain = 4,
  nadapt = 10000,
  M = 500,
  thn = 10,
  nburnin = 200,
  dic = FALSE,
  death_in_R = 0.02,
  beta0 = 0.2586,
  gamma0 = 0.0821,
  R0 = beta0/gamma0,
  gamma0_sd = 0.1,
  R0_sd = 1,
  casename = "tvt.eSIR2",
  file_add = character(0),
  add_death = FALSE,
  save_files = FALSE,
  save_mcmc = FALSE,
  save_plot_data = FALSE,
  eps = 1e-10,
  time_unit = 1
)
Arguments
Y | 
 the time series of daily observed infected compartment proportions.  | 
R | 
 the time series of daily observed removed compartment proportions, including death and recovered.  | 
pi0 | 
 the time-dependent transmission rate modifier   | 
change_time | 
 the change points over time for step function pi, defalt
value is   | 
exponential | 
 logical, whether   | 
lambda0 | 
 the rate of decline in the exponential survival function in
  | 
begin_str | 
 the character of starting time, the default is "01/13/2020".  | 
T_fin | 
 the end of follow-up time after the beginning date
  | 
nchain | 
 the number of MCMC chains generated by
  | 
nadapt | 
 the iteration number of adaptation in the MCMC. We recommend using at least the default value 1e4 to obtained fully adapted chains.  | 
M | 
 the number of draws in each chain, with no thinning. The default is M=5e2 but suggest using 5e5.  | 
thn | 
 the thinning interval between mixing. The total number of draws
thus would become   | 
nburnin | 
 the burn-in period. The default is 2e2 but suggest 2e5.  | 
dic | 
 logical, whether compute the DIC (deviance information criterion) for model selection.  | 
death_in_R | 
 the numeric value of average of cumulative deaths in the removed compartments. The default is 0.4 within Hubei and 0.02 outside Hubei.  | 
beta0 | 
 the hyperparameter of average transmission rate, the default is the one estimated from the SARS first-month outbreak (0.2586).  | 
gamma0 | 
 the hyperparameter of average removed rate, the default is the one estimated from the SARS first-month outbreak (0.0821).  | 
R0 | 
 the hyperparameter of the mean reproduction number R0. The default
is thus the ratio of   | 
gamma0_sd | 
 the standard deviation for the prior distrbution of the
removed rate   | 
R0_sd | 
 the standard deviation for the prior disbution of R0, the default is 1.  | 
casename | 
 the string of the job's name. The default is "tvt.eSIR2".  | 
file_add | 
 the string to denote the location of saving output files and tables.  | 
add_death | 
 logical, whether add the approximate death curve to the plot, default is false.  | 
save_files | 
 logical, whether to save plots to file.  | 
save_mcmc | 
 logical, whether save (  | 
save_plot_data | 
 logical, whether save the plotting data or not.  | 
eps | 
 a non-zero controller so that all the input   | 
time_unit | 
 numeric, newly added argument, which can be changed to an integer (ceiling) of the input to indicate the time unit for each data point. The default is one-day, i.e., we let each input time series data correspond to each day. If this value is set to be 7, each data point represents one-week's aggregated data.  | 
Details
We fit a state-space model with extended SIR, in which a time-varying
transmission rate modifier \pi(t) (between 0 and 1) is introduced to
the model. This allows us to accommodate quarantine protocol changes and
ignored resources of hospitalization. The form of reducing rate may be a step
-function with jumps at times of big policy changes or a smooth exponential
survival function \exp(-\lambda_0t). The parameters of the function and
change points, if any, should be predefined.
Value
casename | 
 the predefined   | 
incidence_mean | 
 mean cumulative incidence, the mean prevalence of cumulative confirmed cases at the end of the study.  | 
incidence_ci | 
 2.5%, 50%, and 97.5% quantiles of the incidences.  | 
out_table | 
 summary tables including the posterior mean of the
prevalence processes of the 3 states compartments (  | 
plot_infection | 
 plot of summarizing and forecasting for the infection
compartment, in which the vertical blue line denotes the last date of data
collected (  | 
plot_removed | 
 plot of summarizing and forecasting for the removed
compartment with lines similar to those in the   | 
spaghetti_plot | 
 20 randomly selected MCMC draws of the first-order
derivative of the posterior prevalence of infection, namely
  | 
first_tp_mean | 
 the date t at which   | 
first_tp_ci | 
 fwith   | 
second_tp_mean | 
 the date t at which   | 
second_tp_ci | 
 with   | 
dic_val | 
 the output of   | 
gelman_diag_list | 
  Since version 0.3.3, we incorporated Gelman And
Rubin's Convergence Diagnostic using   | 
Examples
NI_complete <- c(
  41, 41, 41, 45, 62, 131, 200, 270, 375, 444, 549, 729,
  1052, 1423, 2714, 3554, 4903, 5806, 7153, 9074, 11177,
  13522, 16678, 19665, 22112, 24953, 27100, 29631, 31728, 33366
)
RI_complete <- c(
  1, 1, 7, 10, 14, 20, 25, 31, 34, 45, 55, 71, 94, 121, 152, 213,
  252, 345, 417, 561, 650, 811, 1017, 1261, 1485, 1917, 2260,
  2725, 3284, 3754
)
N <- 58.5e6
R <- RI_complete / N
Y <- NI_complete / N - R # Jan13->Feb 11
### Step function of pi(t)
change_time <- c("01/23/2020", "02/04/2020", "02/08/2020")
pi0 <- c(1.0, 0.9, 0.5, 0.1)
res.step <- tvt.eSIR(Y, R,
  begin_str = "01/13/2020", death_in_R = 0.4,
  T_fin = 200, pi0 = pi0, change_time = change_time, dic = TRUE,
  casename = "Hubei_step", save_files = TRUE,
  save_mcmc = FALSE, M = 5e2, nburnin = 2e2
)
res.step$plot_infection
res.step$plot_removed
res.step$dic_val
### continuous exponential function of pi(t)
res.exp <- tvt.eSIR(Y, R,
  begin_str = "01/13/2020", death_in_R = 0.4,
  T_fin = 200, exponential = TRUE, dic = FALSE, lambda0 = 0.05,
  casename = "Hubei_exp", save_files = FALSE, save_mcmc = FALSE,
  M = 5e2, nburnin = 2e2
)
res.exp$plot_infection
# res.exp$plot_removed
### without pi(t), the standard state-space SIR model without intervention
res.nopi <- tvt.eSIR(Y, R,
  begin_str = "01/13/2020", death_in_R = 0.4,
  T_fin = 200, casename = "Hubei_nopi", save_files = FALSE,
  M = 5e2, nburnin = 2e2
)
res.nopi$plot_infection
# res.nopi$plot_removed
change_time <- c("01/18/2020")
pi0<- c(1.0, 0.9)
NI_complete2 <- c(41, 45, 62, 131)
RI_complete2 <- c(1, 1, 7, 10)
N2 <- 1E3
res1 <- tvt.eSIR(
  Y = RI_complete2 / N2,
  R = (NI_complete2 - RI_complete2) / N2,
  begin_str = "01/10/2020",
  T_fin =10,
  pi0 = pi0,
  change_time = change_time,
  dic = FALSE,
  casename = "Hubei_step",
  save_files = FALSE,
  save_mcmc = FALSE,
  save_plot_data = FALSE,
  M = 50,
  nburnin = 1
)
closeAllConnections()