• DLangLearner (4/4) Jul 17 2015 Excuse me for my trivial question, but I'd like to know how to
• byron (9/13) Jul 17 2015 You want to include [] in the cast so:
• byron (6/19) Jul 17 2015 Ah I miss read, if you want as a float, not a float array you can
• Jacob Carlborg (4/8) Jul 17 2015 I think a union can be used as well, not sure if it's better though.
• byron (14/24) Jul 17 2015 not a bad idea.
• DLangLearner (2/28) Jul 17 2015 thanks for quick reply, i'll plug above lines into my codes.
• Jonathan M Davis via Digitalmars-d-learn (5/9) Jul 17 2015 You could use std.bitmanip.peek or std.bitmanip.read - though you do nee...

"DLangLearner" <Bystander gmail.com> writes:

Excuse me for my trivial question, but I'd like to know how to 
convert byte array to float? What I could think of are 
cast(float)(byte[]) and to!float(byte[]) but they do not work for 
me. Thanks!

"byron" <byron.heads gmail.com> writes:

On Friday, 17 July 2015 at 18:43:27 UTC, DLangLearner wrote:
 Excuse me for my trivial question, but I'd like to know how to 
 convert byte array to float? What I could think of are 
 cast(float)(byte[]) and to!float(byte[]) but they do not work 
 for me. Thanks!

You want to include [] in the cast so:



byte[] b = [1, 2, 3, 4]
byte[] f = cast(float[])b;

writeln(b);
writeln(f);

You can even cast on a slice:

byte[] b = [1, 2, 3, 4, 5, 6, 7, 8]
byte[] f = cast(float[])b[4..8];

"byron" <byron.heads gmail.com> writes:

On Friday, 17 July 2015 at 18:53:24 UTC, byron wrote:
 On Friday, 17 July 2015 at 18:43:27 UTC, DLangLearner wrote:
 Excuse me for my trivial question, but I'd like to know how to 
 convert byte array to float? What I could think of are 
 cast(float)(byte[]) and to!float(byte[]) but they do not work 
 for me. Thanks!

 You want to include [] in the cast so:



 byte[] b = [1, 2, 3, 4]
 byte[] f = cast(float[])b;

 writeln(b);
 writeln(f);

 You can even cast on a slice:

 byte[] b = [1, 2, 3, 4, 5, 6, 7, 8]
 byte[] f = cast(float[])b[4..8];

Ah I miss read, if you want as a float, not a float array you can 
do:

byte[] b = [1, 2, 3, 4];
float f = *cast(float*)b.ptr;

not sure if there is a better way

Jacob Carlborg <doob me.com> writes:

On 2015-07-17 20:58, byron wrote:

 Ah I miss read, if you want as a float, not a float array you can do:

 byte[] b = [1, 2, 3, 4];
 float f = *cast(float*)b.ptr;

 not sure if there is a better way

I think a union can be used as well, not sure if it's better though.

-- 
/Jacob Carlborg

"byron" <byron.heads gmail.com> writes:

On Friday, 17 July 2015 at 19:03:46 UTC, Jacob Carlborg wrote:
 On 2015-07-17 20:58, byron wrote:

 Ah I miss read, if you want as a float, not a float array you 
 can do:

 byte[] b = [1, 2, 3, 4];
 float f = *cast(float*)b.ptr;

 not sure if there is a better way

 I think a union can be used as well, not sure if it's better 
 though.

not a bad idea.

testing on asm.dlang.org both reduce to the same assembly
(-release -inline -O)

float pointerTest(inout byte[4] b) {
    return *cast(float*)b.ptr;
}

float unionTest(inout byte[4] b) {
   union U {
    byte[4] b;
     float f;
   }
   return U(b).f;
}

"DLangLearner" <Bystander gmail.com> writes:

On Friday, 17 July 2015 at 18:58:33 UTC, byron wrote:
 On Friday, 17 July 2015 at 18:53:24 UTC, byron wrote:
 On Friday, 17 July 2015 at 18:43:27 UTC, DLangLearner wrote:
 Excuse me for my trivial question, but I'd like to know how 
 to convert byte array to float? What I could think of are 
 cast(float)(byte[]) and to!float(byte[]) but they do not work 
 for me. Thanks!

 You want to include [] in the cast so:



 byte[] b = [1, 2, 3, 4]
 byte[] f = cast(float[])b;

 writeln(b);
 writeln(f);

 You can even cast on a slice:

 byte[] b = [1, 2, 3, 4, 5, 6, 7, 8]
 byte[] f = cast(float[])b[4..8];

 Ah I miss read, if you want as a float, not a float array you 
 can do:

 byte[] b = [1, 2, 3, 4];
 float f = *cast(float*)b.ptr;

 not sure if there is a better way

thanks for quick reply, i'll plug above lines into my codes.

Jonathan M Davis via Digitalmars-d-learn writes:

On Friday, July 17, 2015 18:43:26 DLangLearner via Digitalmars-d-learn wrote:
 Excuse me for my trivial question, but I'd like to know how to
 convert byte array to float? What I could think of are
 cast(float)(byte[]) and to!float(byte[]) but they do not work for
 me. Thanks!

You could use std.bitmanip.peek or std.bitmanip.read - though you do need to
make sure that you're telling it the right endianness, depending on how the
array of bytes was generated.

- Jonathan M Davis