Are there are any floating points more accurate than Double available in Swift? I know that in C there is the long double, but I can't seem to find its equivalent in Apple's new programming language.
Any help would be greatly appreciated!
Yes there is! There is Float80 exactly for that, it stores 80 bits (duh), 10 bytes. You can use it like any other floating point type. Note that there are Float32, Float64 and Float80 in Swift, where Float32 is just a typealias for Float and Float64 is one for Double
Currently iOS 11+ runs on 64 Bit platform, Double holds Highest among all.
Double has a precision of at least 15 decimal digits, whereas the
precision of Float can be as little as 6 decimal digits. The
appropriate floating-point type to use depends on the nature and range
of values you need to work with in your code. In situations where
either type would be appropriate, Double is preferred.
However in CGFloat The native type used to store the CGFloat, which is Float on 32-bit architectures and Double on 64-bit architectures
https://developer.apple.com/library/content/documentation/Swift/Conceptual/Swift_Programming_Language/TheBasics.html
Related
Learning about the difference between Floats and Doubles in Swift. I can't think of any reasons to use Float. I know there are, and I know I am just not experienced enough to understand them.
So my question is why would you use float in Swift?
why would you use float in Swift
Left to your own devices, you likely never would. But there are situations where you have to. For example, the value of a UISlider is a Float. So when you retrieve that number, you are working with a Float. It’s not up to you.
And so with all the other numerical types. Swift includes a numerical type corresponding to every numerical type that you might possibly encounter as you interface with Cocoa and the outside world.
Float is a typealias for Float32. Float32 and Float16 are incredibly useful for GPU programming with Metal. They both will feel as archaic someday on the GPU as they do on the CPU, but that day is years off.
https://developer.apple.com/metal/
Double
Represents a 64-bit floating-point number.
Has a precision of at least 15 decimal digits.
Float
Float represents a 32-bit floating-point number.
precision of Float can be as little as 6 decimal digits.
The appropriate floating-point type to use depends on the nature and range of values you need to work with in your code. In situations where either type would be appropriate, Double is preferred.
In Swift Programing language official documentation, It says
Double represents a 64-bit floating-point number.
Float represents a 32-bit floating-point number.
Link: https://docs.swift.org/swift-book/LanguageGuide/TheBasics.html#ID321
Then, Why is there Float64? What is the difference between them? Or Are they same?
The headers, found by hitting command+shift+o and searching for Float64, say:
/// A 64-bit floating point type.
public typealias Float64 = Double
/// A 32-bit floating point type.
public typealias Float32 = Float
and
Base floating point types
Float32 32 bit IEEE float: 1 sign bit, 8 exponent bits, 23 fraction bits
Float64 64 bit IEEE float: 1 sign bit, 11 exponent bits, 52 fraction bits
Float80 80 bit MacOS float: 1 sign bit, 15 exponent bits, 1 integer bit, 63 fraction bits
Float96 96 bit 68881 float: 1 sign bit, 15 exponent bits, 16 pad bits, 1 integer bit, 63 fraction bits
Note: These are fixed size floating point types, useful when writing a floating
point value to disk. If your compiler does not support a particular size
float, a struct is used instead.
Use of of the NCEG types (e.g. double_t) or an ANSI C type (e.g. double) if
you want a floating point representation that is natural for any given
compiler, but might be a different size on different compilers.
As a general rule, unless you’re writing code that is dependent on binary representations, you should use the standard Float v Double names. But if you are writing something where binary compatibility is needed (e.g. writing/parsing binary Data to be exchanged with some other platform), then you can use the data types that bear the number of bits in the name, e.g. Float32 vs. Float64 vs. Float80.
Go to the definiation of Float64
/// A 64-bit floating point type.
public typealias Float64 = Double
/// A 32-bit floating point type.
public typealias Float32 = Float
In PLC Structure Text what is main difference between a LReal Vs a Real data type? Which would you use when replacing a double or float when converting from a C based language to structure text with a PLC
LReal is a double precision real, float, or floating point variables that is a 64 bit signed value rather then a real is a single precision real, float, or floating point that is made from a 32 bit signed value. So it stores more in a LReal which makes LReal closer to a Double and a Float. The other thing to keep in mind is depending on the PLC it will convert a Real into a LReal for calculations. Plus a LReal is limited to 15 decimal places rather than a Real is 9 decimal places. So if you need more then 9 decimal places I would recommend LReal but if you need less I would stick with Real because with LReals you have to convert from a Integer to a Real to a LReal. So it would save you a step.
How do I handle floating point issue in Swift if Double's precission is not enough? Is there an analog of Java's BigDecimal?
Swift's Float80 is higher-precision (but not arbitrarily large).
http://swiftdoc.org/v2.0/type/Float80/
I'm very new to Ada and was trying to see if it offers double precision type. I see that we have float and
Put( Integer'Image( Float'digits ) );
on my machine gives a value of 6, which is not enough for numerical computations.
Does Ada has double and long double types as in C?
Thanks a lot...
It is a wee bit more complicated than that.
The only predefined floating-point type that compilers have to support is Float. Compilers may optionally support Short_Float and Long_Float. You should be able to look in appendex F of your compiler documentation to see what it supports.
In practice, your compiler almost certianly defines Float as a 32-bit IEEE float, and Long_Float as a 64-bit. Note that C pretty much works this way too with its float and double. C doesn't actually define the size of those.
If you absolutely must have a certian precision (eg: you are sharing the data with something external that must use IEEE 64-bit), then you should probably define your own float type with exactly that precision. That would ensure your code is either portable to any platform or compiler you move it to, or that it will produce a compiler error so you can fix the issue.
You can create any size Float you like. For a long it would be:
type My_Long_Float is digits 11;
Wiki Books is a good reference for things like this.