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Example nowcast performance evaluation for model specification9 days ago
Packages | Data | Evaluating across a range of nowcast dates | Set the maximum delay | Specify a single model | Looping over multiple nowcast dates | Visual comparison of nowcasts | Evaluation of nowcast performance using scoringutils | Choosing a model specification using quantitative performance evaluation | Summarise performance by model specification | Interpreting the results | Summary
Getting Started with baselinenowcast9 days ago
Introduction | Packages | Data | Pre-processing | Run the baselinenowcast workflow | Visualizing the nowcast | Plot with draws for nowcast only | Add nowcast draws as thin gray lines | Add observed data and final data once | Summary
Nowcasting syndromic surveillance system data: a case study applied to the U.S. National Syndromic Surveillance Program (NSSP) data9 days ago
Introduction | About syndromic surveillance system data | Load packages | NSSP data pre-processing | Load in the line list data | Define the "syndrome" definition | Expand the diagnosis code and their corresponding time stamps into a long dataframe | Remove cases where the diagnoses code was reported before the visit start date by more than 24 hours | Obtain counts of cases by reference date (visit date) and report date (time of first diagnosis) | Pre-processing of larger synthetic dataset | Exploratory data analysis to identify an appropriate maximum delay | Format for baselinenowcast | Specify the baselinenowcast model | Run the baselinenowcast workflow | Summarise and plot the nowcast | Plot nowcast against later observed "final" data | Add observed data and final data once | Summary
Analytic solutions for censored delay distributions2 months ago
Introduction | What are we going to do in this vignette | Analytic solutions for exponentially tilted primary event times | Uniform primary event time ($r=0$) | General partial expectation | General discrete censored delay distribution | Gamma distributed delay times | Gamma partial expectation | Survival function of $S_{+}$ for Gamma distribution | CDF form of $S_{+}$ for Gamma distribution | Gamma discrete censored delay distribution | Log-Normal distribution | Log-Normal partial expectation | Survival function of $S_{+}$ for Log-Normal distribution | CDF form of $S_{+}$ for Log-Normal distribution | Log-Normal discrete censored delay distribution | Weibull distribution | Weibull partial expectation | Survival function of $S_{+}$ for Weibull distribution | CDF form of $S_{+}$ for Weibull distribution | Weibull discrete censored delay distribution | Learning more | References
Why it works2 months ago
Introduction | What are we going to do in this vignette | Censoring and right truncation problems in time to event analysis | Statistical model used in primarycensored | Censored delay time distribution | Survival function of time from the end of the primary censoring window to the secondary event time | CDF form of $S_+$ for uniform primary | Probability of secondary event time within a secondary censoring window | Connections to other approaches | Connection to Park et al 2024 | Learning more | References
Comparing Inference Methods2 months ago
Overview | Setup | Model specifications | Fitting | NUTS with prior initialisation (default) | NUTS with pathfinder initialisation | Pathfinder (approximate inference) | Runtime comparison | Diagnostics | NUTS diagnostics | Pathfinder diagnostics | Nowcast comparison | Posterior parameter comparison | Updating with posterior-as-prior | Summary
Comparing Inference Methods2 months ago
Overview | Setup | Model specifications | Fitting | NUTS with prior initialisation (default) | NUTS with pathfinder initialisation | Pathfinder (approximate inference) | Runtime comparison | Diagnostics | NUTS diagnostics | Pathfinder diagnostics | Nowcast comparison | Posterior parameter comparison | Updating with posterior-as-prior | Summary
Estimating the effective reproduction number in real-time for a single timeseries with reporting delays2 months ago
Use case | What we have | What do we do | Getting setup | Introducing the data: COVID-19 hospitalisations in Germany | Overview | Data transformations | Filtering the data | Visualising the data | Model | Expected hospitalisations | Expected infections | Instantaneous reproduction number | Latent infections | Latent reporting delay and ascertainment | Specifying the model using epinowcast::enw_expectation() | Delay distribution | Defining the delay distribution | Specifying the model using epinowcast::enw_reference() | Observation model and nowcast | Defining the observation model | Specifying the model using epinowcast::enw_obs() | Fitting the model to COVID-19 hospitalisations in Germany | Preprocess the data | Fitting the epinowcast model | Specifying the fitting options | Compiling the model | Fitting the model | Visualising the Nowcast | Plotting the nowcast based on real-time data | Plotting the nowcast based on retrospective data | Posterior predictions for cases by date of positive test and report | Real-time and retrospective estimates of the effective reproduction number | Estimates of the delay from testing positive to hospitalisation both in real-time and retrospectively | Estimates of the number of expected hospitalisations both in real-time and retrospectively | Wrapping up | Summary | Strengths | Limitations | Alternative packages | References
Model Features Summary2 months ago
Overview | Core Capabilities | Different Timesteps and Timespans | Stratified and Multi-Group Nowcasting | Delay Modelling Approaches | Report Date Effects and Structural Reporting | Latent Process Models | Hierarchical Structure | Prior Specification | Missing Data Handling | Model Evaluation | Visualisation | Computational Options | Data Handling | Current Limitations | Further Reading
Estimating the effective reproduction number in real-time for a single timeseries with reporting delays2 months ago
Use case | What we have | What do we do | Getting setup | Introducing the data: COVID-19 hospitalisations in Germany | Overview | Data transformations | Filtering the data | Visualising the data | Model | Expected hospitalisations | Expected infections | Instantaneous reproduction number | Latent infections | Latent reporting delay and ascertainment | Specifying the model using epinowcast::enw_expectation() | Delay distribution | Defining the delay distribution | Specifying the model using epinowcast::enw_reference() | Observation model and nowcast | Defining the observation model | Specifying the model using epinowcast::enw_obs() | Fitting the model to COVID-19 hospitalisations in Germany | Preprocess the data | Fitting the epinowcast model | Specifying the fitting options | Compiling the model | Fitting the model | Visualising the Nowcast | Plotting the nowcast based on real-time data | Plotting the nowcast based on retrospective data | Posterior predictions for cases by date of positive test and report | Real-time and retrospective estimates of the effective reproduction number | Estimates of the delay from testing positive to hospitalisation both in real-time and retrospectively | Estimates of the number of expected hospitalisations both in real-time and retrospectively | Wrapping up | Summary | Strengths | Limitations | Alternative packages | References
Model Features Summary2 months ago
Overview | Core Capabilities | Different Timesteps and Timespans | Stratified and Multi-Group Nowcasting | Delay Modelling Approaches | Report Date Effects and Structural Reporting | Latent Process Models | Hierarchical Structure | Prior Specification | Missing Data Handling | Model Evaluation | Visualisation | Computational Options | Data Handling | Current Limitations | Further Reading
Getting Started with Epinowcast: Nowcasting2 months ago
Quick start | Package | Data | Filtering | Preprocessing | Visualising the data | Choosing a nowcast horizon | Nowcast target | The default model | Posterior predictions | Alternative models | Process model | Reference model: reporting delays | Fitting the alternative models | Results | Diagnostics | Comparing all models | Using package functions rather than S3 methods | Next steps
Getting Started with Epinowcast: Nowcasting2 months ago
Quick start | Package | Data | Filtering | Preprocessing | Visualising the data | Choosing a nowcast horizon | Nowcast target | The default model | Posterior predictions | Alternative models | Process model | Reference model: reporting delays | Fitting the alternative models | Results | Diagnostics | Comparing all models | Using package functions rather than S3 methods | Next steps
Visualising Preprocessed Data2 months ago
Setup | Data | Preprocessing | Latest observations | Cumulative reporting delay | Reporting delay heatmap | Reporting delay quantiles | Notifications by delay group | Using the individual plot functions | Helper functions
Visualising Preprocessed Data2 months ago
Setup | Data | Preprocessing | Latest observations | Cumulative reporting delay | Reporting delay heatmap | Reporting delay quantiles | Notifications by delay group | Using the individual plot functions | Helper functions
Resources to help with model fitting using Stan3 months ago
Epinowcast and Stan | Ensuring you have the proper toolchain | Now install CmdStanR and CmdStan | Epinowcast modelling | Installation | Running your first model | Setting enw_fit_opts | Investigating the quality of the model fit | Sampler settings | chains | threads_per_chain | iter_warmup and iter_sampling | max_treedepth | adapt_delta | Some decent defaults | Model settings | Setting priors | Exploring your data | Posterior predictions | Approaches to solve common problems | My model takes too long to run | Divergent transitions | My $\hat{R}$s are high and my esss are low | The posterior estimates are very wide | Other resources | Technical issues | Learning more about Stan and Bayesian inference
Resources to help with model fitting using Stan3 months ago
Epinowcast and Stan | Ensuring you have the proper toolchain | Now install CmdStanR and CmdStan | Epinowcast modelling | Installation | Running your first model | Setting enw_fit_opts | Investigating the quality of the model fit | Sampler settings | chains | threads_per_chain | iter_warmup and iter_sampling | max_treedepth | adapt_delta | Some decent defaults | Model settings | Setting priors | Exploring your data | Posterior predictions | Approaches to solve common problems | My model takes too long to run | Divergent transitions | My $\hat{R}$s are high and my esss are low | The posterior estimates are very wide | Other resources | Technical issues | Learning more about Stan and Bayesian inference
Hierarchical nowcasting of age stratified COVID-19 hospitalisations in Germany4 months ago
Packages | Data | Data preprocessing | Models | Shared reporting delay distribution | Using the inflated posterior as a prior | Reference day of the week effect | Posterior predictions | Reporting day of the week effect | Age group variation | Variation based on reference date | Variation based on reference date stratified by age | Independent models for each age group. | Alternative models | Evaluation | Summary
Hierarchical nowcasting of age stratified COVID-19 hospitalisations in Germany4 months ago
Packages | Data | Data preprocessing | Models | Shared reporting delay distribution | Using the inflated posterior as a prior | Reference day of the week effect | Posterior predictions | Reporting day of the week effect | Age group variation | Variation based on reference date | Variation based on reference date stratified by age | Independent models for each age group. | Alternative models | Evaluation | Summary
Model definition and implementation4 months ago
Introduction | Decomposition into expected final notifications and report delay components | Expected final notifications | Default model | Generalised model | Instantaneous reproduction number/growth rate | Latent infections/notifications | Latent reporting delay and ascertainment | Delay distribution | Parametric baseline hazard | Non-parametric reference date effect $\delta_{g,t,d}$ and report date effect $\epsilon_{g,t,d}$ | Observation model and nowcast | Accounting for reported cases with a missing reference date | Implementation | Summary of module-parameter mappings | References
Model definition and implementation4 months ago
Introduction | Decomposition into expected final notifications and report delay components | Expected final notifications | Default model | Generalised model | Instantaneous reproduction number/growth rate | Latent infections/notifications | Latent reporting delay and ascertainment | Delay distribution | Parametric baseline hazard | Non-parametric reference date effect $\delta_{g,t,d}$ and report date effect $\epsilon_{g,t,d}$ | Observation model and nowcast | Accounting for reported cases with a missing reference date | Implementation | Summary of module-parameter mappings | References
Case studies4 months ago
Case studies4 months ago
Getting started with primarycensored4 months ago
Introduction | Packages in this getting started vignette. | Generating random samples with rprimarycensored() | Compute the primary event censored cumulative distribution function (CDF) for delays with pprimarycensored() | Compute the primary event censored probability mass function (PMF) with dprimarycensored() | Other key functionality | Learning more
Modular workflow demonstration5 months ago
Introduction | Packages | Data | Model specification | Pre-processing | Estimate delay | Apply the delay to generate a point nowcast | Create plot with data type as a variable | Estimate uncertainty | Generate probabilistic nowcast | Visualizing the nowcast | Plot with draws for nowcast only | Add nowcast draws as thin gray lines | Add observed data and final data once | Summary
Mathematical methods for baselinenowcast6 months ago
Overview | Notation | Pre-processing of the reporting triangle | Delay distribution estimation | Estimating the delay distribution from a reporting matrix | Estimating the delay distribution from a reporting triangle | Point nowcast generation | Uncertainty quantification | Generation of retrospective reporting triangles | Generation of retrospective point nowcast matrices | Fit an observation model to past nowcast errors | Probabilistic nowcast generation | Predicted probabilistic nowcast generation | Combine with observations to obtain probabilistic nowcasts | Zero-handling strategy | Default settings | References
Nowcasting nomenclature11 months ago
Discretised distributions2 years ago
Available distributions | Discretisation and adjustment for maximum delay
Discretised distributions2 years ago
Available distributions | Discretisation and adjustment for maximum delay
Hash-based Matched Pseudo-Random Number Generation3 years ago
Overview | Standards of Matching | Model World and Scenario | Model Implementation | Non-Identity Model Implementation | Higher Resolution Implementation | Comparison | Sampling