A distribution fitting analysis can be started in two ways, either by right clicking on the Distribution Fitting Analysis folder in the study explorer and selecting New, or by going to the Analysis menu and selecting New and then Distribution Fitting Analysis. When a new Distribution Fitting Analysis is selected, the user is required to first enter a Name for the analysis, enter an optional Description, and select a data set from the available data sets stored in the current study DSS file (see chapter 4 for importing data into the study). The Distribution Fitting Analysis editor will not allow further edits by the user until the name is defined and the data set is selected. The list of data that can be selected for a Distribution Fitting Analysis includes nearly all types of DSS data including both time series and paired data (gridded DSS data is not supported). When using time series, data with an irregular interval, like IR-CENTURY and IR-YEAR (E-part pathname), as well as a regular interval, such as 1HOUR and 1DAY can be selected. When using paired data, currently only single column paired data sets are supported within HEC-SSP. Therefore, if a paired data set is selected within the Distribution Fitting Analysis, only the values within the y-column will be imported and an "index" value will be assumed for the x-value. Once a Name is entered and a data set is selected, the DSS File Name and Report File will automatically be entered. The DSS filename is by default a DSS file with the same name as the analysis. The report file is given the same name as the analysis with the extension ".rpt". The Distribution Fitting Analysis editor is shown in the figure below.
Distribution Fitting Analysis Editor.