I tried setting yAxis to integer using NSNumberFormatter,
yAxis.valueFormatter = NSNumberFormatter()
yAxis.valueFormatter.minimumFractionDigits = 0
but the problem here is I am getting duplicate yAxis values - 0, 1, 2, 2, 3, 4 and 5.
How this can be eliminated?
These are the issues I am facing. I tried setting
barChart.leftAxis.axisMaximum = 5.0
barChart.leftAxis.axisMinimum = 0.0
barChart.leftAxis.customAxisMin = 0
barChart.leftAxis.customAxisMax = 5.0
but not helping any suggestions?
This cannot be avoided, because you don't allow fraction digit.
minimumFractionDigits = 0 means no decimal if possible, like 2.1 and 2.0, they will result in 2.1 and 2 ( if maximumFractionDigits = 1)
You need to give the information what's the raw value and what's the value of maximumFractionDigits
EDIT:
the y axis label is calculated by default via internal func computeAxisValues
it calculate the interval based on your max and min value, and the label count.
if _yAxis.isForceLabelsEnabled is enabled, then it will read labelCount and just use (max-min)/(labelCount-1) to calculate the interval. It is disabled by default.
When isForceLabelsEnabled is false, it has a small algorithm to calculate what's the proper way to get a good looking number.
Take a look at internal func computeAxisValues to find out what meets your need.
Update for your second part of question:
you should not touch axisMaximum nor min
enable forceLabelsEnabled
change yAxis.labelCount to 6 or 5 or whatever you like
enable xAxis.wordWrapEnabled
Related
In widget iOS14, I want to show values in graphical form using bar chart.
I have used this library "https://github.com/dawigr/BarChart" to draw bar chart.
But in Xcode12+, it's not showing negative values and considering negative value as 0 and throwing warning as shown in screen shot.
"[SwiftUI] Invalid frame dimension (negative or non-finite)"
You could try to normalise your input Values to prevent getting errors like this.
e.g.: if your data set contains values from -10 to 100, your min normalised value would be 0 and your max normalised value 1. This only works if your numbers are CGFloat, Double or something like this, numbers in Int format would be rounded up.
This could be done by using an extension like this:
extension Array where Element == Double {
var noramlized: [Double] {
if let min = self.min(), let max = self.max() {
return self.map{ ($0 - min) / (max - min) }
}
return []
}
}
I don't no how you get your values for the frame exactly, but I think you did something like this:
// normalise your data set:
let data : [Double] = [Double]()
youChart(inputData: data.noramlized)
// get values for the frame
let height = data.noramlized.max()
// if your normalised value is too small for your purpose (your max will always be 1.0 but in relation to the rest it might fit), you can scale it up like height * 20.
// the width might be a non changing value that you will enter manually or it will append on the count of bars in your chart.
I want to make Y-axis interval with a certain difference. Let's say the multiple of 100 or any fix value, currently it draws with their own interval.
I am sharing my formatting code here.
let leftAxis = chartView.leftAxis
leftAxis.valueFormatter = IntAxisValueFormatter()
leftAxis.granularityEnabled = true
leftAxis.granularity = 1
I am able to solve my challenge, I am adding my fix here. First I calculated the total range then divided them by interval diff and set the LabelCount.
let totalRange = maxY - minY
let interval = 100 //Let's say 100 in my case
leftAxis.setLabelCount(Int(totalRange/interval) + 1, force: true)
One way is you calculate scale value according to your data. And you can use following function to scale as you need. But exact with value difference I don't think it is possible.
self.lineChart.setScaleMinima(1.0, scaleY: 2.0)
In above value first parameter will zoom in horizontally while second will zoom vertically.
Hello i made a "Clicker" as a first project while learning swift i have an automated timer that is supposed to remove some numbers from other numbers but sometimes i get values like 0.600000000000001 and i have no idea why.
Here is my "Attack" function that removes 0.2 from the Health of a zombie.
let fGruppenAttackTimer = NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: Selector("fGruppenAttackTime"), userInfo: nil, repeats: true)
func fGruppenAttackTime() {
zHealth -= 0.2
if zHealth <= 0 {
zHealth = zSize
pPengar += pPengarut
}
...
}
And here is my attackZ button that is supposed to remove 1 from the health of the zombie
#IBAction func attackZ(sender: UIButton) {
zHealth -= Double(pAttack)
fHunger -= 0.05
fGruppenHunger.progress = Float(fHunger / 100)
Actionlbl.text = ""
if zHealth <= 0 {
zHealth = zSize
pPengar += pPengarut
}
}
Lastly here are the variables value:
var zHealth = 10.0
var zSize = 10.0
var pAttack = 1
var pPengar = 0
var pPengarut = 1
When the timer is on and the function is running and i click the button i sometimes get weird values like 0.600000000000001 and if i set the 0.2 in the function to 0.25 i get 0.0999999999999996 sometimes. I wonder why this happens and what to do with it.
In trojanfoe's answer, he shares a link that describes the source of the problem regarding rounding of floating point numbers.
In terms of what to do, there are a number of approaches:
You can shift to integer types. For example, if your existing values can all be represented with a maximum of two decimal places, multiply those by 100 and then use Int types everywhere, excising the Double and Float representations from your code.
You can simply deal with the very small variations that Double type introduces. For example:
If displaying the results in the UI, use NumberFormatter to convert the Double value to a String using a specified number of decimal places.
let formatter = NumberFormatter()
formatter.maximumFractionDigits = 2
formatter.minimumFractionDigits = 0 // or you might use `2` here, too
formatter.numberStyle = .decimal
print(formatter.string(for: value)!)
By the way, the NSNumberFormatter enjoys another benefit, too, namely that it honors the localization settings for the user. For example, if the user lives in Germany, where the decimal place is represented with a , rather than a ., the NSNumberFormatter will use the user's native number formatting.
When testing to see if a number is equal to some value, rather than just using == operator, look at the difference between two values and seeing if they're within some permissible rounding threshold.
You can use Decimal/NSDecimalNumber, which doesn't suffer from rounding issues when dealing with decimals:
var value = Decimal(string: "1.0")!
value -= Decimal(string: "0.9")!
value -= Decimal(string: "0.1")!
Or:
var value = Decimal(1)
value -= Decimal(sign: .plus, exponent: -1, significand: 9)
value -= Decimal(sign: .plus, exponent: -1, significand: 1)
Or:
var value = Decimal(1)
value -= Decimal(9) / Decimal(10)
value -= Decimal(1) / Decimal(10)
Note, I explicitly avoid using any Double values such as Decimal(0.1) because creating a Decimal from a fractional Double only captures whatever imprecision Double entails, where as the three examples above avoid that entirely.
It's because of floating point rounding errors.
For further reading, see What Every Computer Scientist Should Know About Floating-Point Arithmetic.
Squeezing infinitely many real numbers into a finite number of bits
requires an approximate representation. Although there are infinitely
many integers, in most programs the result of integer computations can
be stored in 32 bits. In contrast, given any fixed number of bits,
most calculations with real numbers will produce quantities that
cannot be exactly represented using that many bits. Therefore the
result of a floating-point calculation must often be rounded in order
to fit back into its finite representation. This rounding error is the
characteristic feature of floating-point computation.
In UISlider Control if I set "MinimumValue = 0" & "MaximimValue=2000" then I am not able to set the exact value. On release of slider thumb image it changes the value to + or - 5 to10. My slider width = 225px.
For example:- if I try to set the slider value to 100 then on release of slider thumb it shows me result like 105 or 95.
Code
IBOutlet UISlider * slider;
//"Slider" Object attached using XIB(.NIB)
slider.minimumValue = 0;
slider.maximumValue = 100;
//Attached Below Method Using XIB(.NIB) with "value Changed" event.
-(IBAction)slider_Change:(id)sender;
{
//Assigning value to UITextField
textFiled.text = [NSString stringWithFormat:#"%d",(((int) (slider.value)) * 20)];
}
Because you have set your slider range to be so large each pixel on the screen is equivalent to 8.888.
2000 / 255 = 8.8888888889
To get graduations of 1 you'll need to move the slider 1/8 of a pixel (this is impossible).
Alternatives are:
Make the slider longer
Reduce the slider range
Use a different control UIStepper
In addition to the answer by #rjstelling, it seems as if you are trying to convert the value of the slider to become an integer value. I believe that the default of the slider is a double value, this would cause the value to become rounded as it is increasing, since there will not be decimal values. Unless it is a requirement, see if you can use double.
textFiled.text = [NSString stringWithFormat:#"%f",(slider.value * 20.0)];
or if for some reason you'd want to restrict the level of decimal places you could go, you could do:
textField.text = [NSString stringWithFormat:#"%.1f", slider.value * 20.0];
This will give you the result of a decimal like 1.5 as your answer.
You could do anything with the decimal or even do something like %1.2f, %4.3f, or even %10.4f,
those will produce results like: 0.34, 0012.446, and something extreme like 000000345.1111
Hope this helps
Now i have a working Joystick, but I want to increase the characters speed.
I´m using this one at the moment: http://roadtonerdvana.wordpress.com/2013/09/20/jcinput-a-simple-joystick-for-sprite-kit/
I attached an Imagefile as the moving object, but it´s way too slow for my purpose.
Where and how can I change the speed?
If you read the post you'll know that the joystick returns a x and y value, each ranging from -1 to 1.
Every time you move the joystick, the properties x and y of it change accordingly, the maximum value is 1 and the minimum is -1.
In the update method, you could do something like this to adjust the speed :
-(void)update:(CFTimeInterval)currentTime {
// I'm using the magic number of 5 as an example of how to magnify the speed x5
float speedX = 5 * self.joystick.x;
float speedY = 5 * self.joystick.y;
[self.myLabel setPosition:CGPointMake(self.myLabel.position.x+speedX, self.myLabel.position.y+speedY)];
}