(x => x[keyHint] === datum[keyHint]))
                        ) / 2.0;
                    }else{
                        datum.newinfec_s = (
                            originyValue(datum) + 
                            originyValue(sequential[t-1].find(x => x[keyHint] === datum[keyHint])) + 
                            originyValue(sequential[t-2].find(x => x[keyHint] === datum[keyHint]))
                        ) / 3.0;
                    }
                })
            }

            // split data fr