/// <summary>
/// Method for given a set of tokens and the location of the plot token, create a Plot function object.
/// </summary>
/// <param name="tokens"></param>
/// <param name="i"></param>
/// <returns></returns>
public static PlotFunction plotFunctionHandle(List <Token> tokens, int i)
{
//List for storing the equation to be drawn i.e. "Y=X"
List <Token> equationTokens = getEquation(tokens, ref i);
//skip over the comma
i++;
//Evaluate the range expression i.e. (1<X<10) - it does this by getting Xmin, Xmax and the necessary increment.
Token[] elements = evaluateRange(tokens, ref i);
Token Xmin = elements[0];
Token Xmax = elements[1];
Token inc = elements[2];
PlotFunction newPlot = new PlotFunction(equationTokens, Xmin, Xmax, inc, tokens);
newPlot.curIndex = i;
newPlot.varNameIndex = Convert.ToInt32(elements[3].GetValue());
return(newPlot);
}
public GraphDrawer(PlotFunction plotFunc, MainWindow windowToDrawOn)
{
this.plotFunc = plotFunc;
window = windowToDrawOn;
}
/// <summary>
/// Method called by the interpreter to analyse the set of tokens gathered by the lexer.
/// </summary>
/// <param name="tokens"></param>
/// <returns> the value of the given expression.</returns>
public double AnalyseTokens(List <Token> tokens)
{
//check if there are any function definitions present.
for (int i = 0; i < tokens.Count; i++)
{
//plot func has the following syntax:
//plot(Y=X,Xmin,Xmax,inc)
//So need to gather the algebraic function, Xmin, Xmax and the increment
//And pass it into a PlotFunction object for processing.
if (tokens[i].GetType() == Globals.SUPPORTED_TOKENS.PLOT)
{
//the plot function must be the first token.
if (i != 0)
{
throw new ItemsBeforePlotFunctionException("Plot function found in unexpected token position " + i);
}
PlotFunction plot = PlotFunction.plotFunctionHandle(tokens, i);
if (plot.curIndex != (tokens.Count - 1))
{
throw new ItemsAfterPlotFunctionException("Nothing can follow after the plot function definition.");
}
plot.getValues();
/////////////////////////////////////////////////////////////////
//Draw onto the canvas.
this.g = new GraphDrawer(plot, l.window);
if (Globals.SHOW_GRAPH_CANVAS)
{
g.Draw();
}
/////////////////////////////////////////////////////////////////
//Draw it also onto LiveCharts.
l.dataPoints = g.plotFunc.dataPoints;
l.canvasXLabels = g.Xlabels;
l.Xname = g.plotFunc.X;
l.Yname = g.plotFunc.Y;
if (Globals.SHOW_LIVE_CHARTS)
{
l.Draw();
}
status = STATUSES.PLOT_FUNCTION_CALLED;
return(double.NaN);
}
else if (tokens[i].GetType() == Globals.SUPPORTED_TOKENS.SIN)
{
//create the sin function and find a value.
SinFunction s = new SinFunction(tokens, i, false);
tokens = s.getNewEquation();
}
else if (tokens[i].GetType() == Globals.SUPPORTED_TOKENS.COS)
{
CosFunction c = new CosFunction(tokens, i, false);
tokens = c.getNewEquation();
}
else if (tokens[i].GetType() == Globals.SUPPORTED_TOKENS.TAN)
{
TanFunction t = new TanFunction(tokens, i, false);
tokens = t.getNewEquation();
}
else if (tokens[i].GetType() == Globals.SUPPORTED_TOKENS.LOG)
{
LogFunction l = new LogFunction(tokens, i, true);
tokens = l.getNewEquation();
}
else if (tokens[i].GetType() == Globals.SUPPORTED_TOKENS.LN)
{
LnFunction l = new LnFunction(tokens, i, false);
tokens = l.getNewEquation();
}
else if (tokens[i].GetType() == Globals.SUPPORTED_TOKENS.SQRT)
{
SqrtFunction s = new SqrtFunction(tokens, i, false);
tokens = s.getNewEquation();
}
else if (tokens[i].GetType() == Globals.SUPPORTED_TOKENS.ROOT)
{
RootFunction r = new RootFunction(tokens, i, true);
tokens = r.getNewEquation();
}
else if (tokens[i].GetType() == Globals.SUPPORTED_TOKENS.ABS)
{
AbsFunction a = new AbsFunction(tokens, i, false);
tokens = a.getNewEquation();
}
}
return(processTokens(tokens));
}