Get 16 bit floating point precision as a ushort

daikirai · 2024-11-08T00:10:00.094Z

I saw on SO that using ``Convert.ToUInt16(2.2)`` would give me the 16 bit representation of the float, but instead it just gives me ``2``, what is the proper way to do what i want?

A

Angius•11/8/24, 12:19 AM

Not 100% sure what you want to achieve here

D

daikiraiOP•11/8/24, 12:20 AM

i want 2.2 to be represented as 0x4066

D

daikiraiOP•11/8/24, 12:20 AM

that is the IEEE754 representation

D

daikiraiOP•11/8/24, 12:20 AM

of a 16 bit floating point number

M

MODiX•11/8/24, 12:24 AM

Angius

REPL Result: Success

var bytes = BitConverter.GetBytes(2.2f);
var s = "";

foreach (var b in bytes)
  s += b.ToString("X2");

s

var bytes = BitConverter.GetBytes(2.2f);
var s = "";

foreach (var b in bytes)
  s += b.ToString("X2");

s

var bytes = BitConverter.GetBytes(2.2f);
var s = "";

foreach (var b in bytes)
  s += b.ToString("X2");

s

var bytes = BitConverter.GetBytes(2.2f);
var s = "";

foreach (var b in bytes)
  s += b.ToString("X2");

s

Result: string

CDCC0C40

CDCC0C40

CDCC0C40

CDCC0C40

Compile: 495.085ms | Execution: 40.475ms | React with ❌ to remove this embed.

A

Angius•11/8/24, 12:25 AM

Huh, not quite the expected result

D

daikiraiOP•11/8/24, 12:26 AM

A

Angius•11/8/24, 12:26 AM

That said... not sure how can you represent a float as an ushort

A

Angius•11/8/24, 12:26 AM

One has decimal points... another doesn't

D

daikiraiOP•11/8/24, 12:26 AM

maybe i can use a span :p

A

Angius•11/8/24, 12:27 AM

Unless you do float -> binary -> ushort, to get an ushort value of the binary representation of the float

A

Angius•11/8/24, 12:27 AM

Which would be... largely pointless, but possible

D

daikiraiOP•11/8/24, 12:27 AM

well the goal is float -> binary string

D

daikiraiOP•11/8/24, 12:27 AM

but a 16 bit binary string

A

Angius•11/8/24, 12:29 AM

Floats are 32-bit

D

daikiraiOP•11/8/24, 12:29 AM

are there 16 bit floats then?

D

daikiraiOP•11/8/24, 12:29 AM

i mean

D

daikiraiOP•11/8/24, 12:29 AM

like

D

daikiraiOP•11/8/24, 12:30 AM

a "half" type

D

daikiraiOP•11/8/24, 12:30 AM

floats are singles

A

Angius•11/8/24, 12:30 AM

Not in C#, no

A

Angius•11/8/24, 12:30 AM

float

float

float

float is 32 bits,

double

double

double

double is 64,

decimal

decimal

decimal

decimal is 128

A

Angius•11/8/24, 12:30 AM

Ah, wait

A

Angius•11/8/24, 12:30 AM

https://devblogs.microsoft.com/dotnet/introducing-the-half-type/

A

Angius•11/8/24, 12:31 AM

https://learn.microsoft.com/en-us/dotnet/api/system.half?view=net-8.0

A

Angius•11/8/24, 12:31 AM

Available since .NET 5

D

daikiraiOP•11/8/24, 12:33 AM

now i need to figure out a way to convert a float to a half?

A

Angius•11/8/24, 12:34 AM

You will lose precision doing so

D

daikiraiOP•11/8/24, 12:34 AM

yeah im fine with that

D

daikiraiOP•11/8/24, 12:35 AM

this doesnt seem to work

Convert.ToUInt16((Half)2.2)

Convert.ToUInt16((Half)2.2)

Convert.ToUInt16((Half)2.2)

Convert.ToUInt16((Half)2.2)

Unhandled exception. System.InvalidCastException: Unable to cast object of type 'System.Half' to type 'System.IConvertible'.
   at System.Convert.ToUInt16(Object value)
   at MapEncoder.EncodePosDword(Single x, Single y) in C:\Users\antho\Documents\Code\CSHARP\BitWriter\MapEncoder.cs:line 18
   at MapEncoder.EncodeNotes(List`1 notes) in C:\Users\antho\Documents\Code\CSHARP\BitWriter\MapEncoder.cs:line 59
   at MapEncoder.Encode(Map map) in C:\Users\antho\Documents\Code\CSHARP\BitWriter\MapEncoder.cs:line 90
   at Program.<Main>$(String[] args) in C:\Users\antho\Documents\Code\CSHARP\BitWriter\Program.cs:line 30

Unhandled exception. System.InvalidCastException: Unable to cast object of type 'System.Half' to type 'System.IConvertible'.
   at System.Convert.ToUInt16(Object value)
   at MapEncoder.EncodePosDword(Single x, Single y) in C:\Users\antho\Documents\Code\CSHARP\BitWriter\MapEncoder.cs:line 18
   at MapEncoder.EncodeNotes(List`1 notes) in C:\Users\antho\Documents\Code\CSHARP\BitWriter\MapEncoder.cs:line 59
   at MapEncoder.Encode(Map map) in C:\Users\antho\Documents\Code\CSHARP\BitWriter\MapEncoder.cs:line 90
   at Program.<Main>$(String[] args) in C:\Users\antho\Documents\Code\CSHARP\BitWriter\Program.cs:line 30

Unhandled exception. System.InvalidCastException: Unable to cast object of type 'System.Half' to type 'System.IConvertible'.
   at System.Convert.ToUInt16(Object value)
   at MapEncoder.EncodePosDword(Single x, Single y) in C:\Users\antho\Documents\Code\CSHARP\BitWriter\MapEncoder.cs:line 18
   at MapEncoder.EncodeNotes(List`1 notes) in C:\Users\antho\Documents\Code\CSHARP\BitWriter\MapEncoder.cs:line 59
   at MapEncoder.Encode(Map map) in C:\Users\antho\Documents\Code\CSHARP\BitWriter\MapEncoder.cs:line 90
   at Program.<Main>$(String[] args) in C:\Users\antho\Documents\Code\CSHARP\BitWriter\Program.cs:line 30

Unhandled exception. System.InvalidCastException: Unable to cast object of type 'System.Half' to type 'System.IConvertible'.
   at System.Convert.ToUInt16(Object value)
   at MapEncoder.EncodePosDword(Single x, Single y) in C:\Users\antho\Documents\Code\CSHARP\BitWriter\MapEncoder.cs:line 18
   at MapEncoder.EncodeNotes(List`1 notes) in C:\Users\antho\Documents\Code\CSHARP\BitWriter\MapEncoder.cs:line 59
   at MapEncoder.Encode(Map map) in C:\Users\antho\Documents\Code\CSHARP\BitWriter\MapEncoder.cs:line 90
   at Program.<Main>$(String[] args) in C:\Users\antho\Documents\Code\CSHARP\BitWriter\Program.cs:line 30

A

Angius•11/8/24, 12:35 AM

Well then, look into the

Create

Create

Create

Create methods

A

Angius•11/8/24, 12:35 AM

You can't represent a floating point number as an integer

A

Angius•11/8/24, 12:35 AM

Best case scenario it gets rounded, worst case it gets truncated

D

daikiraiOP•11/8/24, 12:36 AM

oh wait, i think the issue is that ToUInt16 takes in a generic of IConvertable but half doesnt support it

B

blueberriesiftheywerecats•11/8/24, 12:36 AM

just do
Half h = (Half)2.2f

Bblueberriesiftheywerecats just do Half h = (Half)2.2f

D

daikiraiOP•11/8/24, 12:36 AM

yeah that works, its the fact that i cant convert it to a ushort

B

blueberriesiftheywerecats•11/8/24, 12:37 AM

Its 16 bit now, why convert it

Bblueberriesiftheywerecats Its 16 bit now, why convert it

D

daikiraiOP•11/8/24, 12:38 AM

i need to write the binary version of it to a file

D

daikiraiOP•11/8/24, 12:38 AM

well

D

daikiraiOP•11/8/24, 12:38 AM

not to a file

D

daikiraiOP•11/8/24, 12:38 AM

to a string

D

daikiraiOP•11/8/24, 12:38 AM

i need to convert a half to a binary string

A

Angius•11/8/24, 12:39 AM

Do that, then

A

Angius•11/8/24, 12:39 AM

Where does the

ushort

ushort

ushort

ushort come in?

D

daikiraiOP•11/8/24, 12:40 AM

because i cant directly convert a half to a binary string

B

blueberriesiftheywerecats•11/8/24, 12:41 AM

Convert.ToString(half, 2);

D

daikiraiOP•11/8/24, 12:41 AM

uh huh

A

Angius•11/8/24, 12:42 AM

theHalf.ToString("X2")

theHalf.ToString("X2")

theHalf.ToString("X2")

theHalf.ToString("X2")

Ddaikirai uh huh

B

blueberriesiftheywerecats•11/8/24, 12:42 AM

bool?

AAngius `theHalf.ToString("X2")`

D

daikiraiOP•11/8/24, 12:42 AM

thats hex right?