Plot Array as Graph in ImageView - objective-c

Question

How can I plot an array to an imageview as a graph?
I've been testing this in Playground and it works, but how can plot this as an imageview in an actual project?
let sineArraySize = 64
let frequency1 = 4.0
let phase1 = 0.0
let amplitude1 = 2.0
let sineWave = (0..<sineArraySize).map {
amplitude1 * sin(2.0 * M_PI / Double(sineArraySize) * Double($0) * frequency1 + phase1)
}
func plotArrayInPlayground<T>(arrayToPlot:Array<T>, title:String) {
for currentValue in arrayToPlot {
XCPCaptureValue(title, currentValue)
}
}
plotArrayInPlayground(sineWave, "Sine wave 1")

Answer 1

One way you could do this:
// this function creates a plot of an array of doubles where it scales to the provided width and the x-axis is on half height
func plotArray(arr: [Double], width: Double, height: Double) -> NSImage {
if arr.isEmpty { return NSImage() }
let xAxisHeight = height / 2
let increment = width / Double(arr.count)
let image = NSImage(size: NSSize(width: width, height: height))
image.lockFocus()
// set background color
NSColor.whiteColor().set()
NSRectFill(NSRect(x: 0, y: 0, width: width, height: height))
let path = NSBezierPath()
// line width of plot
path.lineWidth = 5
path.moveToPoint(NSPoint(x: 0, y: arr[0] * increment + xAxisHeight))
var i = increment
for value in dropFirst(sineWave) {
path.lineToPoint(NSPoint(x: i, y: value * increment + xAxisHeight))
i += increment
}
// set plot color
NSColor.blueColor().set()
path.stroke()
image.unlockFocus()
return image
}
var imageView = NSImageView()
imageView.image = plotArray(sineWave, 500, 200)
// have fun