The Graph Class III

Graph.java

/** * Draw a graph of the function using the pen in the canvas. * * @f function to be graphed. */ public void draw(Function f) { double xstep = (x1 - x0) / columns; double ystep = (y1 - y0) / rows; for (int column = 0; column < columns; ++column) { double x = x0 + column * xstep; double y = f.evaluate(x); if (y >= y0 && y < y1) { int row = rows - 1 - (int) ((y - y0) / ystep); canvas[row][column] = pen; } } }

xstep and ystep are the granularities of our canvas for the x and the y coordinates, respectively.

The for loop goes through all columns of the graph. The ith column represents x₀ + i · xstep.

	`xstep` and `ystep` are the granularities of our canvas for the x and the y coordinates, respectively.
	The `for` loop goes through all columns of the graph. The ith column represents x₀ + i · xstep.