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// async
encrypt(message).async { ciphertext in /* do somthing */ }
get(URL).async {(data, response, error) in /* do somthing */ }

// await
let ciphertext = encrypt(message).await()
let (data, response, error) = get(URL).await()

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// synchronous API
func encrypt(message: String) -> Task<String> {
    return Task {
        encrypt(message)
    }
}
// asynchronous API
func get(URL: NSURL) -> Task<(NSData?, NSURLResponse?, NSError?)> {
    return Task {completionHandler in
        NSURLSession().dataTaskWithURL(URL, completionHandler: completionHandler).resume()

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Task {
    let enhancedImage = self.applyImageFilter(image)
    Task {self.imageView.image = enhancedImage}.async(.Main)
    let completed = UIView.animateWithDurationAsync(0.3) { self.label.alpha = 1 }.await(.Main)
    // add code to happen next here
}.async()

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dispatch_promise {
    return self.applyImageFilter(image)
}.then { enhancedImage in
    self.imageView.image = enhancedImage
    return UIView.animateWithDurationPromise(0.3) {
        self.label.alpha = 1
    }
}.then {
    // add code to happen next here
}

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// get a global concurrent queue
let queue = dispatch_get_global_queue(QOS_CLASS_USER_INTERACTIVE, 0)
// submit a task to the queue for background execution
dispatch_async(queue) {
    let enhancedImage = self.applyImageFilter(image) // expensive operation taking a few seconds
    // update UI on the main queue
    dispatch_async(dispatch_get_main_queue()) {
        self.imageView.image = enhancedImage
        UIView.animateWithDuration(0.3, animations: {
            self.imageView.alpha = 1

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function getCharCodes(s) {
  return s.toUpperCase().split("").map(c => c.charCodeAt(0))
}

function zip(a, b) {
    return a.map((char,i) => [char, b[i % b.length]]);
}

function decrypt(ciphertext, key) {
  const plaintextCharCode = zip(getCharCodes(ciphertext), getCharCodes(key)).map(pair => (pair[0] - pair[1] + 26) % 26 + "A".charCodeAt(0))

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function click(el) {
	var evt = document.createEvent("MouseEvents");
	evt.initMouseEvent("click", true, true, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null);
	el.dispatchEvent(evt);
}

function click2(el) {
	var evt = document.createEvent("MouseEvents");
	evt.initMouseEvent("mousedown", true, false, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null);

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Math 115A

Chapter 1

1.2-1.6

Definitions

• Definition of a vector space

---

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// stores an array of images (PImage[]) for each scene
ArrayList<PImage[]> scenes;
// keeps track of the index of the current scene
int sceneIndex = 0;
// used to animate the images of the current scene
int frameIndex = 0;

// keep track of the last mouse position
float clickedX;
float clickedY;

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# To pngs 1 frame per second 
# https://trac.ffmpeg.org/wiki/Create%20a%20thumbnail%20image%20every%20X%20seconds%20of%20the%20video
mkdir frames && ffmpeg -i video.mov -vf fps=1 frames/ffout%03d.png

# screen recording to gif
mkdir bufferFrames && ffmpeg -i video.mov -vf scale=320:-1 -r 30 bufferFrames/ffout%03d.png && convert -delay 4.167 -loop 0 bufferFrames/ffout*.png ZLHistogramAudioPlotBuffer.gif