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TSView Time Series Viewing Tools <br />Appendix - TSView - 2 <br />Overview <br /> <br />The TSView package contains integrated software components that can be used with software <br />applications to enable time series viewing capabilities. The main purpose of the TSView package is to <br />provide sim ple, consistent, and flexible displays that can be used in a variety of applications with little or <br />no reconfiguration. TSView also provides features to configure and process time series products (e.g., <br />graphs), where the time series data are stored separ ately from the configuration information. <br /> <br />The TSView package has been developed by Riverside Technology, inc., using Java technology. TSView <br />interfaces can be embedded in Java applications and can be used in web pages either as embedded applets <br />or stand -alone windows. TSView tools operate similarly on Microsoft Windows and UNIX operating <br />systems. <br /> <br />This appendix describes general TSView features and can be used as a reference for how to configure and <br />use TSView components. Software program documentation may include specific information about <br />using TSView features. <br /> <br />Time Series Terminology <br /> <br />The TSView package treats time series as objects that can be read, manipulated, and output in various <br />formats. A time series is defined as having header information (a ttributes) and data, which usually <br />consists of a series of date/time versus data pairs. Internally, time series are considered to have either <br />regular interval (equal spacing of date/time) or irregular interval (e.g., occasional observations). Regular <br />tim e series lend themselves to simpler storage and faster processing because date/time information can be <br />stored only for the endpoints. The following basic attributes are stored for each time series: <br /> <br />• Data interval as an interval base (e.g., Month , Hour ) a nd multiplier (e.g., 1 for month, or 24 for <br />hour) - in many cases, the multiplier is 1 and is not shown in output (e.g., Month rather than <br />1Month ), <br />• Data type (e.g., Streamflow ), which ideally can be checked to determine if a time series contains <br />mean, inst antaneous, or accumulated values, <br />• Units (e.g., CFS ), which ideally can be used to make units conversions and look up precision for <br />output, <br />• Period of record, using dates that are of an appropriate precision for the interval, <br />• Data limits (the maximum, minimu m, etc.), <br />• Description (generally a station, structure, or sensor name), <br />• Missing data value (used internally to mark missing data and trigger data filling, often -999 ), <br />• Comments (often station comments, if available), <br />• Genesis history (a list of comments abo ut how the time series was created). <br /> <br />In order to uniquely and consistently identify time series, a multi -part time series identifier is employed, <br />having the following parts: <br /> <br />• Location (or location -sublocation) <br />• Data source <br />• Data type (or datatype -subdatatyp e) <br />• Data interval (time step) <br />• Scenario <br /> <br />156