I'm trying to create a candlestick chart using Charts
As you guys can notice from my screenshot, the chart only shows the highest and lowest values instead of displaying the values for all the candles. Is there any way I can implement that with the Charts framework?
Thanks in advance.
If you want to display only highest and lowest values, you need to implement you own renderer inherited from CandleStickChartRenderer. In fact you just need to override one function drawValues(context: CGContext).
I have made some example which contain a hundred lines of code, but in fact my custom code contains about thirty lines.
class MyCandleStickChartRenderer: CandleStickChartRenderer {
private var _xBounds = XBounds() // Reusable XBounds object
private var minValue: Double
private var maxValue: Double
// New constructor
init (view: CandleStickChartView, minValue: Double, maxValue: Double) {
self.minValue = minValue
self.maxValue = maxValue
super.init(dataProvider: view, animator: view.chartAnimator, viewPortHandler: view.viewPortHandler)
}
// Override draw function
override func drawValues(context: CGContext)
{
guard
let dataProvider = dataProvider,
let candleData = dataProvider.candleData
else { return }
guard isDrawingValuesAllowed(dataProvider: dataProvider) else { return }
var dataSets = candleData.dataSets
let phaseY = animator.phaseY
var pt = CGPoint()
for i in 0 ..< dataSets.count
{
guard let dataSet = dataSets[i] as? IBarLineScatterCandleBubbleChartDataSet
else { continue }
let valueFont = dataSet.valueFont
let trans = dataProvider.getTransformer(forAxis: dataSet.axisDependency)
let valueToPixelMatrix = trans.valueToPixelMatrix
_xBounds.set(chart: dataProvider, dataSet: dataSet, animator: animator)
let lineHeight = valueFont.lineHeight
let yOffset: CGFloat = lineHeight + 5.0
for j in stride(from: _xBounds.min, through: _xBounds.range + _xBounds.min, by: 1)
{
guard let e = dataSet.entryForIndex(j) as? CandleChartDataEntry else { break }
guard e.high == maxValue || e.low == minValue else { continue }
pt.x = CGFloat(e.x)
if e.high == maxValue {
pt.y = CGFloat(e.high * phaseY)
} else if e.low == minValue {
pt.y = CGFloat(e.low * phaseY)
}
pt = pt.applying(valueToPixelMatrix)
if (!viewPortHandler.isInBoundsRight(pt.x))
{
break
}
if (!viewPortHandler.isInBoundsLeft(pt.x) || !viewPortHandler.isInBoundsY(pt.y))
{
continue
}
if dataSet.isDrawValuesEnabled
{
// In this part we draw min and max values
var textValue: String?
var align: NSTextAlignment = .center
if e.high == maxValue {
pt.y -= yOffset
textValue = "← " + String(maxValue)
align = .left
} else if e.low == minValue {
pt.y += yOffset / 5
textValue = String(minValue) + " →"
align = .right
}
if let textValue = textValue {
ChartUtils.drawText(
context: context,
text: textValue,
point: CGPoint(
x: pt.x,
y: pt.y ),
align: align,
attributes: [NSAttributedStringKey.font: valueFont, NSAttributedStringKey.foregroundColor: dataSet.valueTextColorAt(j)])
}
}
}
}
}
}
Do not forget use you custom renderer for you chart. ;)
myCandleStickChartView.renderer = MyCandleStickChartRenderer(view: myCandleStickChartView, minValue: 400, maxValue: 1450)
Related
I'm trying to make something simple to test Vision Framework on MacOS.
I tried to modify code from this tutorial to use a single image from screenshot instead of camera feed.
https://www.appcoda.com/vision-framework-introduction/
However, I get this error:
Error Domain=com.apple.vis Code=3 "Failed to create image for processing due to invalid requested buffer dimensions"
Is it because screenshot image doesn't fit certain specification? Do I need to preprocess the file?
If so, how can I process it in order to fit the dimensions?
My testing code is below.
Thanks!
import Cocoa
import Vision
class ViewController: NSViewController {
var requests = [VNRequest]()
func start() {
let textRequest = VNDetectTextRectanglesRequest(completionHandler: self.detectTextHandler)
textRequest.reportCharacterBoxes = true
self.requests = [textRequest]
let url = URL(fileURLWithPath:NSString(string:"~/Screenshot.png").expandingTildeInPath)
let imageRequestHandler = VNImageRequestHandler(url:url)
do {
try imageRequestHandler.perform(self.requests)
} catch {
print(error)
}
}
func detectTextHandler(request: VNRequest, error: Error?) {
guard let observations = request.results else {
print("no result")
return
}
let result = observations.map({$0 as? VNTextObservation})
DispatchQueue.main.async() {
for region in result {
guard let rg = region else {
continue
}
self.highlightWord(box: rg)
if let boxes = region?.characterBoxes {
for characterBox in boxes {
self.highlightLetters(box: characterBox)
}
}
}
}
}
func highlightWord(box: VNTextObservation) {
guard let boxes = box.characterBoxes else {
return
}
var maxX: CGFloat = 9999.0
var minX: CGFloat = 0.0
var maxY: CGFloat = 9999.0
var minY: CGFloat = 0.0
for char in boxes {
if char.bottomLeft.x < maxX {
maxX = char.bottomLeft.x
}
if char.bottomRight.x > minX {
minX = char.bottomRight.x
}
if char.bottomRight.y < maxY {
maxY = char.bottomRight.y
}
if char.topRight.y > minY {
minY = char.topRight.y
}
}
let xCord = maxX
let yCord = (1 - minY)
let width = (minX - maxX)
let height = (minY - maxY)
let frame = CGRect(x: xCord, y: yCord, width: width, height: height)
print("Word: \(frame)")
}
func highlightLetters(box: VNRectangleObservation) {
let xCord = box.topLeft.x
let yCord = (1 - box.topLeft.y)
let width = (box.topRight.x - box.bottomLeft.x)
let height = (box.topLeft.y - box.bottomLeft.y)
let frame = CGRect(x: xCord, y: yCord, width: width, height: height)
print("Letter: \(frame)")
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
start()
}
override var representedObject: Any? {
didSet {
// Update the view, if already loaded.
}
}
}
I want to show the arrow of the maximum and minimum value just like the picture below.
Does anyone have ideas about how to achieve it using iOS-Charts? Thanks a lot.
You need to write your own custom renderer for CandleStickChartView.
Fortunately, in your case you need overwrite only one method.
So, inherit class from CandleStickChartRenderer and override method drawValues(context: CGContext). You can just copy/paste most of the code from parent's method and make only necessary changes.
class MyCandleStickChartRenderer: CandleStickChartRenderer {
internal var _xBounds = XBounds()
var minValue: Double
var maxValue: Double
init (view: CandleStickChartView, minValue: Double, maxValue: Double) {
self.minValue = minValue
self.maxValue = maxValue
super.init(dataProvider: view, animator: view.chartAnimator, viewPortHandler: view.viewPortHandler)
}
override func drawValues(context: CGContext)
{
// ... I remove some code that was not changed ...
for j in stride(from: _xBounds.min, through: _xBounds.range + _xBounds.min, by: 1)
{
guard let e = dataSet.entryForIndex(j) as? CandleChartDataEntry else { break }
// need to show only min and max values
guard e.high == maxValue || e.low == minValue else { continue }
pt.x = CGFloat(e.x)
if e.high == maxValue {
pt.y = CGFloat(e.high * phaseY)
} else if e.low == minValue {
pt.y = CGFloat(e.low * phaseY)
}
pt = pt.applying(valueToPixelMatrix)
// ... I remove some code that was not changed ...
if dataSet.isDrawValuesEnabled
{
var textValue: String?
var align: NSTextAlignment = .center
// customize position for min/max value
if e.high == maxValue {
pt.y -= yOffset
textValue = "← " + String(maxValue)
align = .left
} else if e.low == minValue {
pt.y += yOffset / 5
textValue = String(minValue) + " →"
align = .right
}
if let textValue = textValue {
ChartUtils.drawText(
context: context,
text: textValue,
point: CGPoint(
x: pt.x,
y: pt.y ),
align: align,
attributes: [NSAttributedStringKey.font: valueFont, NSAttributedStringKey.foregroundColor: dataSet.valueTextColorAt(j)])
}
}
}
}
}
}
Also you need to create instance of your renderer and set it as property in your chart view.
myCandleStickChartView.renderer = MyCandleStickChartRenderer(view: candleStickChartView, minValue: 400, maxValue: 1450)
And in the end ...
I'm building a pie chart by chart iOS framework. I'm able to hide the value and label when the the slice is tiny but I can't hide the value line for tiny slice.
If I add this code on setDataCount()
set.valueLineWidth = 0.0
It will hide all the value line. How to hide it by the size of slice?
#IBOutlet weak var myChart: PieChartView!
var valueColors = [UIColor]()
var dataEntries = [PieChartDataEntry]()
var record = [Record]()
var category = [String]()
var categoryTotal : [Double] = []
var categoryArray : [String] = []
func setDataCount() {
var totalValue = 0.0
for a in categoryTotal {
totalValue += a
}
UserDefaults.standard.set(totalValue, forKey: "totalValue")
valueAndColor()
let set = PieChartDataSet(values: dataEntries, label: nil)
set.colors = valueColors
set.valueLinePart1OffsetPercentage = 0.8
set.valueLinePart1Length = 0.2
set.valueLinePart2Length = 0.4
set.xValuePosition = .outsideSlice
set.yValuePosition = .outsideSlice
set.selectionShift = 0.0
let data = PieChartData(dataSet: set)
let Formatter:ChartFormatter = ChartFormatter()
data.setValueFormatter(Formatter)
data.setValueFont(.systemFont(ofSize: 11, weight: .light))
data.setValueTextColor(.black)
myChart.data = data
myChart.highlightValues(nil)
}
func valueAndColor(){
for i in 0..<categoryArray.count{
let dataEntry = PieChartDataEntry(value: categoryTotal[i], label: categoryArray[i % categoryArray.count])
dataEntries.append(dataEntry)
//I'm using this code to hide the label
let value = categoryTotal[i]
let total = UserDefaults.standard.double(forKey: "totalValue")
var valueToUse = value/total * 100
valueToUse = Double(round(10*valueToUse)/10)
let minNumber = 10.0
if(valueToUse < minNumber) {
dataEntries[i].label = ""
}else{
dataEntries[i].label = categoryArray[i % categoryArray.count]
}
if categoryArray[i] == "吃喝" {
valueColors.append(UIColor.yellow)
}...
}
I'm using this code to hide the value %
public class ChartFormatter: NSObject, IValueFormatter{
public func stringForValue(_ value: Double, entry: ChartDataEntry, dataSetIndex: Int, viewPortHandler: ViewPortHandler?) -> String {
let total = UserDefaults.standard.double(forKey: "totalValue")
var valueToUse = value/total * 100
valueToUse = Double(round(10*valueToUse)/10)
let minNumber = 10.0
if(valueToUse < minNumber) {
return ""
}
else {
let pFormatter = NumberFormatter()
pFormatter.numberStyle = .percent
pFormatter.maximumFractionDigits = 1
pFormatter.multiplier = 1
pFormatter.percentSymbol = " %"
let hideValue = pFormatter.string(from: NSNumber(value: value))
return String(hideValue ?? "0")
}
}
}
Inside the file PieChartRenderer change from this:
if dataSet.valueLineColor != nil
{
context.setStrokeColor(dataSet.valueLineColor!.cgColor)
context.setLineWidth(dataSet.valueLineWidth)
context.move(to: CGPoint(x: pt0.x, y: pt0.y))
context.addLine(to: CGPoint(x: pt1.x, y: pt1.y))
context.addLine(to: CGPoint(x: pt2.x, y: pt2.y))
context.drawPath(using: CGPathDrawingMode.stroke)
}
to this:
if dataSet.valueLineColor != nil
{
if(valueText == "") {
context.setStrokeColor(UIColor.clear.cgColor)
}
else {
context.setStrokeColor(dataSet.valueLineColor!.cgColor)
}
context.setLineWidth(dataSet.valueLineWidth)
context.move(to: CGPoint(x: pt0.x, y: pt0.y))
context.addLine(to: CGPoint(x: pt1.x, y: pt1.y))
context.addLine(to: CGPoint(x: pt2.x, y: pt2.y))
context.drawPath(using: CGPathDrawingMode.stroke)
}
The change basically checks if the valueText is the empty string, and if so it changes the linecolor to a clear color.
Is there a easy way to create a procedural level with a cellular automaton in swift/SpriteKit(library?)? I want to create a 'cave' with 11 fields in the height and 22 width. These should be randomly created and every field without a wall should be reached.
I just found a documentation using Objective-C, which I am not familiar with. I spend quite some time trying to understand the code and follow the example without success.
PS: If there is an easier way I appreciate some algorithms
I made a Playground where you can experiment
//: Playground - noun: a place where people can play
import UIKit
import SpriteKit
import XCPlayground
class Cave {
var cellmap:[[Bool]]
let chanceToStartAlive = 35
let deathLimit = 3
let birthLimit = 4
var xCell = 40 // number of cell in x axes
var yCell = 20 // number of cell in y axes
var wCell = 20 // cell width
var hCell = 20 // cell height
init(){
cellmap = Array(count:yCell, repeatedValue:
Array(count:xCell, repeatedValue:false))
cellmap = self.initialiseMap(xCell, yIndex:yCell)
}
func initialiseMap(xIndex:Int, yIndex:Int) -> [[Bool]]{
var map:[[Bool]] = Array(count:yIndex, repeatedValue:
Array(count:xIndex, repeatedValue:false))
for y in 0...(yIndex - 1) {
for x in 0...(xIndex - 1) {
let diceRoll = Int(arc4random_uniform(100))
if diceRoll < chanceToStartAlive {
map[y][x] = true
} else {
map[y][x] = false
}
}
}
return map
}
func addSprite(scene:SKScene){
for (indexY, row) in cellmap.enumerate(){
for (indexX, isWall) in row.enumerate(){
if isWall {
let wall = SKSpriteNode(color: UIColor.redColor(), size: CGSize(width: wCell, height: hCell))
wall.position = CGPoint(x: (indexX * wCell) + (wCell / 2) , y: (indexY * hCell) + (hCell / 2) )
scene.addChild(wall)
}
}
}
}
func countAliveNeighbours(x:Int, y:Int) -> Int{
var count = 0
var neighbour_x = 0
var neighbour_y = 0
for i in -1...1 {
for j in -1...1 {
neighbour_x = x + j
neighbour_y = y + i
if(i == 0 && j == 0){
} else if(neighbour_x < 0 || neighbour_y < 0 || neighbour_y >= cellmap.count || neighbour_x >= cellmap[0].count){
count = count + 1
} else if(cellmap[neighbour_y][neighbour_x]){
count = count + 1
}
}
}
return count
}
func applyRules(){
var newMap:[[Bool]] = Array(count:yCell, repeatedValue:
Array(count:xCell, repeatedValue:false))
for y in 0...(cellmap.count - 1) {
for x in 0...(cellmap[0].count - 1) {
let nbs = countAliveNeighbours( x, y: y);
if(cellmap[y][x]){
if(nbs < deathLimit){
newMap[y][x] = false;
}
else{
newMap[y][x] = true;
}
} else{
if(nbs > birthLimit){
newMap[y][x] = true;
}
else{
newMap[y][x] = false;
}
}
}
}
cellmap = newMap
}
}
let view:SKView = SKView(frame: CGRectMake(0, 0, 1024, 768))
XCPShowView("Live View", view: view)
let scene:SKScene = SKScene(size: CGSizeMake(1024, 768))
scene.scaleMode = SKSceneScaleMode.AspectFit
let aCave = Cave()
aCave.applyRules()
aCave.applyRules()
aCave.addSprite(scene)
view.presentScene(scene)
Updated the playground code for Xcode 8 and Swift 3. I swapped the X and Y cell count since you will likely see the view in a "portrait" orientation.
Remember to open the Assistant Editor to view the results. It also takes a little while to execute, so give it a couple of minutes to run the algorithm.
//: Playground - noun: a place where people can play
import UIKit
import SpriteKit
import XCPlayground
import PlaygroundSupport
class Cave {
var cellmap:[[Bool]]
let chanceToStartAlive = 35
let deathLimit = 3
let birthLimit = 4
var xCell = 20 // number of cell in x axes
var yCell = 40 // number of cell in y axes
var wCell = 20 // cell width
var hCell = 20 // cell height
init(){
cellmap = Array(repeating:
Array(repeating:false, count:xCell), count:yCell)
cellmap = self.initialiseMap(xIndex: xCell, yIndex:yCell)
}
func initialiseMap(xIndex:Int, yIndex:Int) -> [[Bool]]{
var map:[[Bool]] = Array(repeating:
Array(repeating:false, count:xIndex), count:yIndex)
for y in 0...(yIndex - 1) {
for x in 0...(xIndex - 1) {
let diceRoll = Int(arc4random_uniform(100))
if diceRoll < chanceToStartAlive {
map[y][x] = true
} else {
map[y][x] = false
}
}
}
return map
}
func addSprite(scene:SKScene){
for (indexY, row) in cellmap.enumerated(){
for (indexX, isWall) in row.enumerated(){
if isWall {
let wall = SKSpriteNode(color: UIColor.red, size: CGSize(width: wCell, height: hCell))
wall.position = CGPoint(x: (indexX * wCell) + (wCell / 2) , y: (indexY * hCell) + (hCell / 2) )
scene.addChild(wall)
}
}
}
}
func countAliveNeighbours(x:Int, y:Int) -> Int{
var count = 0
var neighbour_x = 0
var neighbour_y = 0
for i in -1...1 {
for j in -1...1 {
neighbour_x = x + j
neighbour_y = y + i
if(i == 0 && j == 0){
} else if(neighbour_x < 0 || neighbour_y < 0 || neighbour_y >= cellmap.count || neighbour_x >= cellmap[0].count){
count = count + 1
} else if(cellmap[neighbour_y][neighbour_x]){
count = count + 1
}
}
}
return count
}
func applyRules(){
var newMap:[[Bool]] = Array(repeating:
Array(repeating:false, count:xCell), count:yCell)
for y in 0...(cellmap.count - 1) {
for x in 0...(cellmap[0].count - 1) {
let nbs = countAliveNeighbours( x: x, y: y);
if(cellmap[y][x]){
if(nbs < deathLimit){
newMap[y][x] = false;
}
else{
newMap[y][x] = true;
}
} else{
if(nbs > birthLimit){
newMap[y][x] = true;
}
else{
newMap[y][x] = false;
}
}
}
}
cellmap = newMap
}
}
let view:SKView = SKView(frame: CGRect(x: 0, y: 0, width: 768, height: 1024))
let scene:SKScene = SKScene(size: CGSize(width: 768, height: 1024))
scene.scaleMode = SKSceneScaleMode.aspectFit
PlaygroundPage.current.needsIndefiniteExecution = true
PlaygroundPage.current.liveView = view
let aCave = Cave()
aCave.applyRules()
aCave.applyRules()
aCave.addSprite(scene: scene)
view.presentScene(scene)
Can I make an array of SK nodes of which one is selected randomly and brought from the top to bottom of the screen. For example say I have 25 or so different platforms that will be falling out of the sky on a portrait iPhone. I need it to randomly select one of the platforms from the array to start and then after a certain amount of time/ or pixel space randomly select another to continue the same action until reaching the bottom etc. Im new to swift but have a pretty decent understanding of it. I haven't been able to find out how to create an array of SKsprite nodes yet either. Could someone help with this?
So far the only way I've been able to get any sort of effect similar to what I've wanted is by placing each of the nodes off the screen and adding them to a dictionary and making them move like this
class ObstacleStatus {
var isMoving = false
var timeGapForNextRun = Int(0)
var currentInterval = Int(0)
init(isMoving: Bool, timeGapForNextRun: Int, currentInterval: Int) {
self.isMoving = isMoving
self.timeGapForNextRun = timeGapForNextRun
self.currentInterval = currentInterval
}
func shouldRunBlock() -> Bool {
return self.currentInterval > self.timeGapForNextRun
}
and
func moveBlocks(){
for(blocks, ObstacleStatus) in self.blockStatuses {
var thisBlock = self.childNodeWithName(blocks)
var thisBlock2 = self.childNodeWithName(blocks)
if ObstacleStatus.shouldRunBlock() {
ObstacleStatus.timeGapForNextRun = randomNum()
ObstacleStatus.currentInterval = 0
ObstacleStatus.isMoving = true
}
if ObstacleStatus.isMoving {
if thisBlock?.position.y > blockMaxY{
thisBlock?.position.y -= CGFloat(self.fallSpeed)
}else{
thisBlock?.position.y = self.origBlockPosistionY
ObstacleStatus.isMoving = false
}
}else{
ObstacleStatus.currentInterval++
}
}
}
using this for the random function
func randomNum() -> Int{
return randomInt(50, max: 300)
}
func randomInt(min: Int, max:Int) -> Int {
return min + Int(arc4random_uniform(UInt32(max - min + 1)))
}
All this has been doing for me is moving the pieces down at random timed intervals often overlapping them, But increasing the min or max of the random numbers doesn't really have an affect on the actual timing of the gaps. I need to be able to specify a distance or time gap.
One of many possible solutions is to create a falling action sequence which calls itself recursively until no more platform nodes are left. You can control the mean "gap time" and the range of its random variation. Here is a working example (assuming the iOS SpriteKit game template):
import SpriteKit
extension Double {
var cg: CGFloat { return CGFloat(self) }
}
extension Int {
var cg: CGFloat { return CGFloat(self) }
}
func randomInt(range: Range<Int>) -> Int {
return range.startIndex + Int(arc4random_uniform(UInt32(range.endIndex - range.startIndex)))
}
extension Array {
func randomElement() -> Element? {
switch self.count {
case 0: return nil
default: return self[randomInt(0..<self.count)]
}
}
func apply<Ignore>(f: (T) -> (Ignore)) {
for e in self { f(e) }
}
}
class GameScene: SKScene {
var screenWidth: CGFloat { return UIScreen.mainScreen().bounds.size.width }
var screenHeight: CGFloat { return UIScreen.mainScreen().bounds.size.height }
let PlatformName = "Platform"
let FallenPlatformName = "FallenPlatform"
func createRectangularNode(#x: CGFloat, y: CGFloat, width: CGFloat, height: CGFloat) -> SKShapeNode {
let rect = CGRect(x: x, y: y, width: width, height: height)
let path = UIBezierPath(rect: rect)
let node = SKShapeNode(path: path.CGPath)
return node
}
func createPlatformNodes(numNodes: Int, atHeight: CGFloat) -> [SKShapeNode] {
var padding = 20.cg
let width = (screenWidth - padding) / numNodes.cg - padding
padding = (screenWidth - width * numNodes.cg) / (numNodes.cg + 1)
let height = width / 4
var nodes = [SKShapeNode]()
for x in stride(from: padding, to: numNodes.cg * (width + padding), by: width + padding) {
let node = createRectangularNode(x: x, y: atHeight, width: width, height: height)
node.fillColor = SKColor.blackColor()
node.name = PlatformName
nodes.append(node)
}
return nodes
}
func createFallingAction(#by: CGFloat, duration: NSTimeInterval, timeGap: NSTimeInterval, range: NSTimeInterval = 0) -> SKAction {
let gap = SKAction.waitForDuration(timeGap, withRange: range)
// let fall = SKAction.moveToY(toHeight, duration: duration) // moveToY appears to have a bug: behaves as moveBy
let fall = SKAction.moveByX(0, y: -by, duration: duration)
let next = SKAction.customActionWithDuration(0) { [unowned self]
node, time in
node.name = self.FallenPlatformName
self.fallNextNode()
}
return SKAction.sequence([gap, fall, next])
}
func fallNextNode() {
if let nextNode = self[PlatformName].randomElement() as? SKShapeNode {
let falling = createFallingAction(by: screenHeight * 0.7, duration: 1, timeGap: 2.5, range: 2) // mean time gap and random range
nextNode.runAction(falling)
} else {
self.children.apply { ($0 as? SKShapeNode)?.fillColor = SKColor.redColor() }
}
}
override func didMoveToView(view: SKView) {
self.backgroundColor = SKColor.whiteColor()
for platform in createPlatformNodes(7, atHeight: screenHeight * 0.8) {
self.addChild(platform)
}
fallNextNode()
}
}