public void mousePressed(MouseEvent me) {
POINT = me.getPoint();
double xa = POINT.x - w / 2 - (a - originX) * scale;
F.addVariable("x", a);
double ya = POINT.y - h / 2 + (F.getValue() - originY) * scale;
if (xa * xa + ya * ya < rr) {
newA = true;
}
requestFocus();
}
public void drawEndpoints(Graphics2D g) {
F.addVariable("x", a);
drawPoint(g, a, F.getValue(), Color.red, overA);
try {
drawPoint(
g,
a,
Double.parseDouble(F.evaluate(F.differentiate(F.getTopNode(), "x")).toString()),
Color.red,
false);
} catch (ParseException e) {
} catch (Exception e) {
}
}
public void draw(Graphics2D g) {
F.addVariable("x", a);
double fa = F.getValue();
// draw tangent line
double m;
double[] P = toCartesianPoint(0, 0);
double[] Q = toCartesianPoint(w, 0);
g.setStroke(new BasicStroke(3.0f));
try {
m = Double.parseDouble(F.evaluate(F.differentiate(F.getTopNode(), "x")).toString());
drawLine(g, P[0], fa + m * (P[0] - a), Q[0], fa + m * (Q[0] - a), Color.gray);
applet.setStat("Slope \u2248 ", m, Color.red);
} catch (ParseException e) {
} catch (Exception e) {
}
// draw derivative from b to c
try {
double start = w / 2 + (b - originX) * scale;
double stop = w / 2 + (c - originX) * scale;
GeneralPath path = new GeneralPath();
F.addVariable(variable, b);
double y = Double.parseDouble(F.evaluate(F.differentiate(F.getTopNode(), "x")).toString());
path.moveTo(start, (float) (h / 2 - (y - originY) * scale));
while (start < stop) {
F.addVariable(variable, (start - w / 2) / scale + originX);
y = Double.parseDouble(F.evaluate(F.differentiate(F.getTopNode(), "x")).toString());
path.lineTo(start, (float) (h / 2 - (y - originY) * scale));
start++;
}
g.setColor(Color.red);
g.setStroke(curve);
g.draw(path);
} catch (ParseException e) {
} catch (Exception e) {
}
}