No longer actively maintained. I am too lazy to keep it working all the time. Sorry. Please use the official page - Onemocneni aktualne MZCR

koronagrafy

Mathematical prediction of COVID-19 pandemic's development. Fetching data from czech-covid-db and Johns Hopkins University COVID-19 repository. Everything is downloaded and calculated on the client side. This project has no server side, except the program that updates czech-covid-db.

Getting currently displayed data from console

If you want the data in JSON format, open your browser's developer console and type one of these commands:

• tests: console.log(JSON.stringify(datasets.tests, null, 1))
• confirmed cases: console.log(JSON.stringify(datasets.confirmed, null, 1))
• recovered: console.log(JSON.stringify(datasets.recovered, null, 1))
• deaths: console.log(JSON.stringify(datasets.deaths, null, 1))
• growth factor: console.log(JSON.stringify(datasets.spreadGrowthFactor, null, 1))
• prediction: console.log(JSON.stringify(datasets.prediction, null, 1))

Used libraries

• Chart.js for visualisation
• Moment.js for easy date/time manipulation
• PapaParse for csv parsing (they say it's faster than string splitting, but idk)
• NProgress for the loading bar at top

Math behind the scenes

Explanation of the function is in about. Here is how the code for it works. The prediction dataset is created in function calculatePredictions(). There are many lines in the function that provide the growth factor (MtimesP) it has to use and other things depending on user configuration. The essential parts are these:

• The loop. One iteration calculates a result for one day. while(lastResult <= populationSize && Math.round(lastResult) != Math.round(resultBeforeInfectionPeriod) ){
  In the loop, one of these calculations happen:
  • If selected function is Henry's logistic/first: result = lastResult + MtimesP*(1-(lastResult/populationSize))*(lastResult-resultBeforeInfectionPeriod);
  • If it is the other function (Henry's probabilistic), MtimesP is converted to meetInThisDay, then result = populationSize*(1 - (1-lastResult/populationSize)*Math.pow((1- probabilisticProbability*(lastResult-resultBeforeInfectionPeriod)/populationSize),meetInThisDay));