Title: Plot a smiley face function in C#

This example shows how you can plot a smiley face function defined by the following equations.

[x^2 + y^2 - 225] * [x^2 + y^2 - 10000] * [(x - 45)^2 + (y - 35)^2 - 225] * [(x + 45)^2 + (y - 35)^2 - 225] = 0 [y + Sqrt(16 - x^2)] = 0

You can use the techniques described in the following examples to plot the equations.

• Pass a method to another method in C#
• Plot an equation containing two variables in C#

This example uses the PlotFunction method from the first of the previous examples in the following calls:

PlotFunction(gr, F1, -6, -6, 6, 6, dx, dy); PlotFunction(gr, F2, -6, -6, 6, 6, dx, dy);

The following code shows the F1 and F2 functions.

// Calculate: // [x^2 + y^2 - 225] * // [x^2 + y^2 - 10000] * // [(x - 45)^2 + (y - 35)^2 - 225] * // [(x + 45)^2 + (y - 35)^2 - 225] private float F1(float x, float y) { // Flip y to make the image appear right side up. return (x * x + y * y - 25f) * (x * x + y * y - 1f) * ((x - 2.5f) * (x - 2.5f) + (y - 2.0f) * (y - 2.0f) - 1f) * ((x + 2.5f) * (x + 2.5f) + (y - 2.0f) * (y - 2.0f) - 1f); } // Calculate: // y + Sqrt(16 - x^2) private float F2(float x, float y) { return (float)(y + Math.Sqrt(12.25f - x * x)); }

Download the example to experiment with it and to see additional details.