SWMM5 Delphi GUI Fstats.pas Summary

 Below is a high-level summary of Fstats.pas, the Delphi unit that implements the TStatsReportForm in SWMM. This form is used to produce a statistical analysis report of user-specified events (e.g., peaks, totals, durations) taken from simulation results.

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1. Purpose

Fstats.pas defines TStatsReportForm, an MDI child form that:

1. Takes a TStatsSelection record (from Dstats.pas) describing which object, variable, and analysis type (peak, mean, etc.) to study.
2. Uses Ustats.GetStats to compute the event-based statistics (peak values, durations, volumes, etc.), returning:
   • A list of individual events (EventList).
   • Summary results in a TStatsResults record.
3. Displays the results in a PageControl with these pages:
   • StatsPage: textual summary of overall event stats (mean, min, max, etc.).
   • TablePage: rank-ordered table of events.
   • HistogramPage: histogram plot of event values.
   • FrequencyPlotPage: exceedance frequency plot of event values.

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2. Components and Displays

1. StatsPage (StatsMemo):

   • Lists key summary information:
     • Object name, Variable name, Units
     • Number of events, min/max/mean values, standard deviation, skewness
     • Period of record and event threshold criteria
   • This text is built from templates in StatsText.

2. TablePage (EventTable):

   • A rank-ordered list of all events, each with date/time, value, duration, frequency, etc.
   • Includes sortable columns (headers that user can click).
   • Event data come from the EventList.

3. HistogramPage (HistoChart):

   • A bar chart (TBarSeries) of event values, grouped into bins.
   • Code calculates bin widths, min & max event values, etc.

4. FrequencyPlotPage (FreqChart):

   • An exceedance frequency chart (TAreaSeries), showing event value on x-axis vs. log-based exceedance freq. on y-axis.

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3. Key Methods

1. CreateReport(StatsSelection):

   • Stores the selected statistical options in a local variable (Stats).
   • Sets up object & variable names, units, and the display caption.
   • (Later, RefreshReport actually runs the analysis.)

2. RefreshReport:

   • Clears any existing events from EventList.
   • Calls Ustats.GetStats to compute new event data & summary results.
   • Fills in StatsPage (text), TablePage (grid), HistogramPage (bar chart), FrequencyPlotPage (exceedance chart).

3. RefreshStatsPage / RefreshTablePage / RefreshHistoPage / RefreshFreqPage:

   • Each routine populates one of the 4 pages with the newly computed data.

4. CopyTo / Print:

   • Allows user to copy or print the currently visible page.
   • For the histogram & frequency pages, uses graph copy/print logic (see Ugraph).
   • For the summary page, copies the text from StatsMemo.
   • For the table page, copies or prints the rank-ordered event table.

5. SelectAll:

   • Selects all rows/columns in the event table (for e.g. copying to clipboard).

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4. Overall Flow

A TStatsSelection describing the event-based analysis is passed to CreateReport, which sets up references to the object/variable and calls RefreshReport. That method invokes Ustats to compute statistics and fill EventList & Results. The results then populate four pages (text summary, event table, histogram, frequency plot). The form supports copying/printing either the text/table pages or the chart pages, and provides “select all” for the event table.

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In summary, Fstats.pas manages the creation and display of a statistics report on events (like storm events or flow events) in SWMM, showing both textual summaries and graphical charts of the event data.