///gets all stock information from a year ago to today
private static TimeInterval[] GetTimeIntervals(string _stockName)
{
bool _unavailable = false; //bool to work out when to stop scraping information
int _n = 0; // integar to count page numbers
List <TimeInterval> _timeIntervals = new List <TimeInterval>(); //list to store everyday of stock information specified
string _startDate = DateHandling.GetCurrentYahooDate(0);
string _endDate = DateHandling.GetStartDate();
//this loop will only run while there is information to scrape
while (!_unavailable)
{
string _address = GetAddress(_stockName, _startDate, _endDate, _n); // address for next webpage
TimeInterval[] _currentTimeIntervals = GetInformationOfPage(_address); // getting stock info of webpage
if (_currentTimeIntervals == null)
{
_unavailable = true;
}
else
{
_timeIntervals.AddRange(_currentTimeIntervals);
}
_n++;
}
_timeIntervals.Reverse();
return(_timeIntervals.ToArray());
}
///gets all the stock information from a specified webpage
private static TimeInterval[] GetInformationOfPage(string _address)
{
List <TimeInterval> _timeIntervals = new List <TimeInterval>(); //list to store stock info from webpage
HtmlDocument _doc = LoadDoc(_address); //grabbing all the information of the webpage
//array containing all the rows in the table
HtmlNodeCollection _rows = _doc.DocumentNode.SelectNodes("//*[@class='yfnc_tabledata1']");
if (_rows == null)
{
return(null); //if rows are empty, no more information to scrape
}
string _previousDate = ""; //string to make sure same date isn't entered twice and instead the original date is changed
int _missingCells = 0; //integar to keep the row and timeInterval count alligned in the case of duplicate dates
//loop going through each row and creating or ammending timeIntervals with the information
for (int i = 0; i < _rows.Count; i++)
{
int _cell = (i * 7) - _missingCells; //integar that splits the row into itss seperate columns
if (_cell >= _rows.Count)
{
break; //if the last cell has been reached, stop scraping
}
if (_rows[_cell].InnerText.Contains("adjusted"))
{
break; //last cell could contain text, in this case stop scraping
}
//checking if the date is a duplicate, could be something happened to stock on that day or dividend
bool _sameDate = (_rows[_cell].InnerText == _previousDate);
bool _dividend = (_rows[_cell + 1].InnerText.Contains("Dividend"));
//if the cell is a dividend, ammends the previous time interval to include dividend payment
if (_dividend)
{
_timeIntervals[_timeIntervals.Count - 1].dividend = ConvertDividendToFloat(_rows[_cell + 1].InnerText);
}
//normal circumstances, adding a new time interval to the list
if (!_sameDate && DateHandling.IsDate(_rows[_cell].InnerText))
{
_timeIntervals.Add(
new TimeInterval(
_rows[_cell].InnerText, //date
ConvertStringToFloat(_rows[_cell + 1].InnerText), //open
ConvertStringToFloat(_rows[_cell + 2].InnerText), //high
ConvertStringToFloat(_rows[_cell + 3].InnerText), //low
ConvertStringToFloat(_rows[_cell + 4].InnerText), //close
ConvertStringToFloat(_rows[_cell + 5].InnerText), //volume
0 //dividend
)
);
_previousDate = _rows[_cell].InnerText; //sets previous date to this date
}
if (_sameDate)
{
_missingCells += 5; //makes up for missing cells due to dividend or other text
}
}
return(_timeIntervals.ToArray());
}
///returns string[] of dividend dates
private static string[] GetDividendDates(TimeInterval[] _timeIntervals)
{
List <string> _dates = new List <string>(); //list to store dates
//loops through all dates forwards to get dividend dates
for (int i = 0; i < _timeIntervals.Length; i++)
{
if (_timeIntervals[i].dividend != 0)
{
_dates.Add(_timeIntervals[i].date);
}
}
return(DateHandling.FixDates(_dates.ToArray()));
}
private void Init()
{
lbl_DividendForecaster.BackColor = Colours.dividend;
radiob_Same.BackColor = Colours.dividend;
radiob_Different.BackColor = Colours.dividend;
int _days = MainForm.Instance.days;
try { dates = DateHandling.GetDatesWithinTime(MainForm.Instance.stock.dates, _days); }
catch {
MessageBox.Show("Cannot enter dividends until stock and timescale have been confirmed");
this.Close();
return;
}
MainForm.Instance.divNumber = dates.Length;
this.Show();
combob_Date.Items.AddRange(dates);
foreach (string date in dates)
{
predictions.Add(new float[3]);
}
}
public static string[] GetDatesWithinTime(string[] _dates, int _days)
{
List <string> _datesWithinTime = new List <string>();
int[] _daysUntilPayments = new int[_dates.Length]; //array to store days until dividend payment
//loops through all dividends and gets the days until the payment
for (int i = 0; i < _daysUntilPayments.Length; i++)
{
_daysUntilPayments[i] = DateHandling.DaysUntil(_dates[i]);
}
for (int i = 0; i < _daysUntilPayments.Length; i++)
{
if (_daysUntilPayments[i] <= _days)
{
_datesWithinTime.Add(_dates[i]);
}
}
return(_datesWithinTime.ToArray());
}
//calculates indivdual forward price
private static float GetForwardPrice(StockInformation _stock, float dividend, int days, float riskFreeRate)
{
//initial
double _forward = _stock.price * Math.Exp(riskFreeRate / 100 * days);
int[] _daysUntilPayments = new int[_stock.dates.Length]; //array to store days until dividend payment
//loops through all dividends and gets the days until the payment
for (int i = 0; i < _daysUntilPayments.Length; i++)
{
_daysUntilPayments[i] = DateHandling.DaysUntil(_stock.dates[i]);
}
//loops through checking if dividend will be paid within time, if so it takes payment off price
for (int i = 0; i < _daysUntilPayments.Length; i++)
{
if (_daysUntilPayments[i] < days)
{
_forward -= dividend * Math.Exp(riskFreeRate * (days - _daysUntilPayments[i]));
}
}
return((float)_forward);
}
