// Create the Vector that represents the Center of the gradient 
var centerVector = new CIVector (100, 100); // Default is [150 150]

// Create the two colors to form the Gradient.
var color1 = CIColor.FromRgba (1, 0, 1, 1);
var color0 = CIColor.FromRgba (0, 1, 1, 1);

// Constructor the actual GaussianGradient filter
var gaussGradient = new CIGaussianGradient ()
{
	Center = centerVector,
	Color0 = color0,
	Color1 = color1,
	Radius = 280f // Default is 300
};

// The Generator Filters need to be cropped before they can be displayed
var crop = new CICrop (IUCrop () 
{ 
	Image = gaussGradient.OutputImage,
	// Create the Bounds based on the Size of the application Window. (UIWindow)
	Rectangle = new CIVector (0, 0, window.Bounds.Width, window.Bounds.Height) 
};	

// Get the Final Cropped Image
var output = crop.OutputImage;
	
// To render the results, we need to create a context, and then
// use one of the context rendering APIs, in this case, we render the
// result into a CoreGraphics image, which is merely a useful representation
//
var context = CIContext.FromOptions (null);

var cgimage = context.CreateCGImage (output, output.Extent);

// The above cgimage can be added to a screen view, for example, this
// would add it to a UIImageView on the screen:
myImageView.Image = UIImage.FromImage (cgimage);