int getFirstRainfall(int j)
//
// Input: j = rain gage index
// Output: returns TRUE if successful
// Purpose: positions rainfall record to date with first rainfall.
//
{
int k; // time series index
float vFirst; // first rain volume (ft or m)
double rFirst; // first rain intensity (in/hr or mm/hr)
// --- assign default values to date & rainfall
Gage[j].startDate = NO_DATE;
Gage[j].rainfall = 0.0;
// --- initialize internal cumulative rainfall value
Gage[j].rainAccum = 0;
// --- use rain interface file if applicable
if ( Gage[j].dataSource == RAIN_FILE )
{
if ( Frain.file && Gage[j].endFilePos > Gage[j].startFilePos )
{
// --- retrieve 1st date & rainfall volume from file
fseek(Frain.file, Gage[j].startFilePos, SEEK_SET);
fread(&Gage[j].startDate, sizeof(DateTime), 1, Frain.file);
fread(&vFirst, sizeof(float), 1, Frain.file);
Gage[j].currentFilePos = ftell(Frain.file);
// --- convert rainfall to intensity
Gage[j].rainfall = convertRainfall(j, (double)vFirst);
return 1;
}
return 0;
}
// --- otherwise access user-supplied rainfall time series
else
{
k = Gage[j].tSeries;
if ( k >= 0 )
{
// --- retrieve first rainfall value from time series
if ( table_getFirstEntry(&Tseries[k], &Gage[j].startDate,
&rFirst) )
{
// --- convert rainfall to intensity
Gage[j].rainfall = convertRainfall(j, rFirst);
return 1;
}
}
return 0;
}
}
int getNextRainfall(int j)
//
// Input: j = rain gage index
// Output: returns 1 if successful; 0 if not
// Purpose: positions rainfall record to date with next non-zero rainfall
// while updating the gage's next rain intensity value.
//
// Note: zero rainfall values explicitly entered into a rain file or
// time series are skipped over so that a proper accounting of
// wet and dry periods can be maintained.
//
{
int k; // time series index
float vNext; // next rain volume (ft or m)
double rNext; // next rain intensity (in/hr or mm/hr)
Gage[j].nextRainfall = 0.0;
do
{
if ( Gage[j].dataSource == RAIN_FILE )
{
if ( Frain.file && Gage[j].currentFilePos < Gage[j].endFilePos )
{
fseek(Frain.file, Gage[j].currentFilePos, SEEK_SET);
fread(&Gage[j].nextDate, sizeof(DateTime), 1, Frain.file);
fread(&vNext, sizeof(float), 1, Frain.file);
Gage[j].currentFilePos = ftell(Frain.file);
rNext = convertRainfall(j, (double)vNext);
}
else return 0;
}
else
{
k = Gage[j].tSeries;
if ( k >= 0 )
{
if ( !table_getNextEntry(&Tseries[k],
&Gage[j].nextDate, &rNext) ) return 0;
rNext = convertRainfall(j, rNext);
}
else return 0;
}
} while (rNext == 0.0);
Gage[j].nextRainfall = rNext;
return 1;
}
int getNextRainfall(int j)
//
// Input: j = rain gage index
// Output: returns TRUE if successful
// Purpose: positions rainfall record to date with next rainfall.
//
{
int k; // time series index
int result; // result of table query (TRUE/FALSE)
float vNext; // next rain volume (ft or m)
double rNext; // next rain intensity (in/hr or mm/hr)
Gage[j].nextRainfall = 0.0;
if ( Gage[j].dataSource == RAIN_FILE )
{
if ( Frain.file && Gage[j].currentFilePos < Gage[j].endFilePos )
{
fseek(Frain.file, Gage[j].currentFilePos, SEEK_SET);
fread(&Gage[j].nextDate, sizeof(DateTime), 1, Frain.file);
fread(&vNext, sizeof(float), 1, Frain.file);
Gage[j].currentFilePos = ftell(Frain.file);
Gage[j].nextRainfall = convertRainfall(j, (double)vNext);
return 1;
}
return 0;
}
else
{
k = Gage[j].tSeries;
if ( k >= 0 )
{
result = table_getNextEntry(&Tseries[k], &Gage[j].nextDate, &rNext);
if ( result ) Gage[j].nextRainfall = convertRainfall(j, rNext);
return result;
}
return 0;
}
}
