The National Hurricane Center announced Thursday afternoon that Harvey was "rapidly intensifying" and became a hurricane after initially being categorized as a tropical storm.
The hard part is being categorized.
For the survival analysis, easting was used as a categorical variable after it was categorized into four zones (<500 km east [zone 1], 500 to <600 km east [zone 2], 600 to <700 km east [zone 3], and  700 km east [zone 4]).
Not long after Sandy was categorized a tropical depression off the coast of Venezuela on Friday, Oct. 19, the M.T.A. had begun gathering cots and bedding, food and water, for track workers and hydraulics teams and even the train crews that would shut the system down and start it back up.
By definition, patients who underwent bronchoscopy within 24 hours after intubation were categorized as the early bronchoscopy group.
Microorganisms isolated from positive blood cultures within the first 100 days after transplant were categorized as of likely origin from periodontal, oral, or any body sites.
After applications are categorized by region and high school, the system generally sorts applicants alphabetically by their last name.
After specimens were categorized as non-pregnant from the pregnancy-unknown category and approximately 18% (21/119) of repeatedly reactive EIA and Western blot-negative and 35% (20/57) of indeterminate specimens were reclassified because they may have represented true infections, the false-positive rate among non-pregnant persons was 0.16%.
Because the herds were sampled at 3-monthly intervals, the variable 'days after treatment' was categorized in 3 intervals: '0 3 months', '3 6 months', '>6 months'.
