This code focuses on the evaporation and traveling of respiratory droplets exhaled from upper repisratory tract. The formulation, results and findings can be found in "Zhao, Lei, et al. "COVID-19: Effects of weather conditions on the propagation of respiratory droplets"medRxiv (2020), doi: https://doi.org/10.1101/2020.05.24.20111963". The main function is driver_function.m. You will get the droplet evaporation information after providing key environmental parameters (temperature, humidity, wind) and initial conditions (droplet diameter, velocity).