Mapping Toolbox

Time Notation

Times can be represented as variables in the Mapping Toolbox in three ways: hours, seconds, and hours-minutes-seconds. The toolbox provides functions for converting between these formats.

Hours

This is the default time unit notation for the toolbox.

Hour notation is simply decimal notation in terms of hours. Two hours and fifteen minutes would be 2.25.

Seconds

Seconds notation is simply decimal notation in terms of seconds. One hour would be 3600.

Hours-Minutes-Seconds

Hours-minutes-seconds, or hms notation, is analogous to dms notation for angles. In text, an hms time would be hh:mm:ss. For example, 12:36:15 is 12 hours, 36 minutes, and 15 seconds. In the Mapping Toolbox, when hms times are represented by a single number, the format is hhmm.ss. For example, 12:36:15 is 1236.15.

The real value of this notation is in entering data already in this format. The toolbox includes the mat2hms function to easily input hms data, which functions very similarly to the mat2dms function described earlier.

Note    Care must be exercised when working with the hms format; for example, two times in this format cannot simply be added. It is advisable to convert hms data to decimal hours before working extensively with it.

Converting Between Time Unit Formats

Time units can be converted using functions similar to those described for angle unit conversions. These include hr2sec and hms2hr, as well as a general conversion function timedim, which works just like angledim.

Angles, Times, and Distances - Units and Notation

Distance Notation