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Why float is called as 'float', not 'real'?

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Good day everyone. This sounds like a stupid question, but I became
just curious yesterday, and I looked up several textbooks. However, no
textbooks on computer language (that I have ) mentioned this. So I am
asking to you, gurus...

Is there any particular reason to call 'float' instead of 'real'?

Mar 24 '07 #1
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16 Replies


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On Mar 24, 12:13 am, "DirtyHarry" <kim20...@gmail.comwrote:
Good day everyone. This sounds like a stupid question, but I became
just curious yesterday, and I looked up several textbooks. However, no
textbooks on computer language (that I have ) mentioned this. So I am
asking to you, gurus...

Is there any particular reason to call 'float' instead of 'real'?
What you call 'double' - real32?

I'm certainly not well versed in the history of the languages ( I
suspect this dates back to C ) nonetheless, Fortran is the only
language I've encountered that used REAL. Granted, rational,
irrational etc - numbers are approximations of real arithmetic, I
suspect machine precision limitations plays an important role. Beyond
that I'm unsure what the impetus is.

Mar 24 '07 #2

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DirtyHarry wrote:
Good day everyone. This sounds like a stupid question, but I became
just curious yesterday, and I looked up several textbooks. However, no
textbooks on computer language (that I have ) mentioned this. So I am
asking to you, gurus...

Is there any particular reason to call 'float' instead of 'real'?
float stands for "floating point" as opposed to "fixed point". It is a
more accurate description than "real" since not all real numbers are
representable by a floating point number.
Mar 24 '07 #3

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"DirtyHarry" <ki******@gmail.comwrote in message
news:11**********************@e65g2000hsc.googlegr oups.com...
Good day everyone. This sounds like a stupid question, but I became
just curious yesterday, and I looked up several textbooks. However, no
textbooks on computer language (that I have ) mentioned this. So I am
asking to you, gurus...

Is there any particular reason to call 'float' instead of 'real'?
So if we call a float a real, does that mean we have to call an int a fake?
float is more descriptive I believe.
Mar 24 '07 #4

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DirtyHarry wrote:
Is there any particular reason to call 'float' instead of 'real'?
Because a 'float' is not a real number, but a floating point number.
There's a big difference.
Mar 24 '07 #5

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Dnia Fri, 23 Mar 2007 21:49:04 -0700, ma740988 napisał(a):
Fortran is the only language I've encountered that used REAL.
Pascal used it too ;)
And it's probably the language used formerly by OP, causing
his confusion upon encountering 'float' ;J

--
SasQ
Mar 24 '07 #6

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Jim Langston wrote:
"DirtyHarry" <ki******@gmail.comwrote in message
news:11**********************@e65g2000hsc.googlegr oups.com...
>Good day everyone. This sounds like a stupid question, but I became
just curious yesterday, and I looked up several textbooks. However, no
textbooks on computer language (that I have ) mentioned this. So I am
asking to you, gurus...

Is there any particular reason to call 'float' instead of 'real'?

So if we call a float a real, does that mean we have to call an int a
fake?
I guess the OP is talking about the mathematical term as in "real number",
not the opposite of "fake".
float is more descriptive I believe.
Agreed.

Mar 24 '07 #7

P: n/a
DirtyHarry wrote:
Good day everyone. This sounds like a stupid question, but I became
just curious yesterday, and I looked up several textbooks. However, no
textbooks on computer language (that I have ) mentioned this. So I am
asking to you, gurus...

Is there any particular reason to call 'float' instead of 'real'?
Counter question: Is there any particular reason to call it 'real' instead
of 'float'?

Mar 24 '07 #8

P: n/a
DirtyHarry wrote:
Good day everyone. This sounds like a stupid question, but I became
just curious yesterday, and I looked up several textbooks. However, no
textbooks on computer language (that I have ) mentioned this. So I am
asking to you, gurus...

Is there any particular reason to call 'float' instead of 'real'?
float is short for "floating-point." double is short for
double-precision floating point.

--

-- Pete
Roundhouse Consulting, Ltd. (www.versatilecoding.com)
Author of "The Standard C++ Library Extensions: a Tutorial and
Reference." (www.petebecker.com/tr1book)
Mar 24 '07 #9

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On Mar 24, 8:43 am, Rolf Magnus <ramag...@t-online.dewrote:
Counter question: Is there any particular reason to call it 'real' instead
of 'float'?
I suspect the OP's thought process reflects what I - perhaps all of us
- was taught in a mathematical sense. In that regard, I'd talk in
terms of integers, real numbers and complex numbers. These are terms
everyone understands including C / C++ programmers. I had a similar
question hen I first encountered 'floats and double'. I'd like to
believe Real32 and Real64 would suffice, but considering C/C++ has
been around for sometime, you chalk it up to 'it is what it is' and
move on.

In the end, the OP could always - worse case - typedef the float/
double to what he/she considers a more meaningful description. That's
the beauty of the language.

Mar 24 '07 #10

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Gianni Mariani ha scritto:

It is a
more accurate description than "real" since not all real numbers are
representable by a floating point number.
neither are all the integers by int...
Mar 24 '07 #11

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Giff wrote:
Gianni Mariani ha scritto:

It is a
>more accurate description than "real" since not all real numbers are
representable by a floating point number.

neither are all the integers by int...
All integers from INT_MIN to INT_MAX are. For 'float' that is not so.

V
--
Please remove capital 'A's when replying by e-mail
I do not respond to top-posted replies, please don't ask
Mar 24 '07 #12

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On Mar 24, 8:58 am, "ma740988" <ma740...@gmail.comwrote:
On Mar 24, 8:43 am, Rolf Magnus <ramag...@t-online.dewrote:
Counter question: Is there any particular reason to call it 'real' instead
of 'float'?

I suspect the OP's thought process reflects what I - perhaps all of us
- was taught in a mathematical sense. In that regard, I'd talk in
terms of integers, real numbers and complex numbers. These are terms
everyone understands including C / C++ programmers. I had a similar
question hen I first encountered 'floats and double'. I'd like to
believe Real32 and Real64 would suffice, but considering C/C++ has
been around for sometime, you chalk it up to 'it is what it is' and
move on.
A "real" type would have to be able to represent irrational numbers -
which floating point numbers cannot represent, since all floating
point numbers (except for infinity) are rational.
In the end, the OP could always - worse case - typedef the float/
double to what he/she considers a more meaningful description. That's
the beauty of the language.
Defining a "real" typedef for float is not going to change the types
of numbers that a float can represent. So the typedef would not change
the fact that a float does not represent real numbers, but the "real"
name could mislead anyone who sees it - into believing that it does.

Greg

Mar 25 '07 #13

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* Greg Herlihy:
On Mar 24, 8:58 am, "ma740988" <ma740...@gmail.comwrote:
>On Mar 24, 8:43 am, Rolf Magnus <ramag...@t-online.dewrote:
>>Counter question: Is there any particular reason to call it 'real' instead
of 'float'?
I suspect the OP's thought process reflects what I - perhaps all of us
- was taught in a mathematical sense. In that regard, I'd talk in
terms of integers, real numbers and complex numbers. These are terms
everyone understands including C / C++ programmers. I had a similar
question hen I first encountered 'floats and double'. I'd like to
believe Real32 and Real64 would suffice, but considering C/C++ has
been around for sometime, you chalk it up to 'it is what it is' and
move on.

A "real" type would have to be able to represent irrational numbers -
which floating point numbers cannot represent, since all floating
point numbers (except for infinity) are rational.
>In the end, the OP could always - worse case - typedef the float/
double to what he/she considers a more meaningful description. That's
the beauty of the language.

Defining a "real" typedef for float is not going to change the types
of numbers that a float can represent. So the typedef would not change
the fact that a float does not represent real numbers, but the "real"
name could mislead anyone who sees it - into believing that it does.
Well. 'int' is rather misleading too. Come to think of it, is there
any type name in a programming language that isn't misleading, when one
thinks of it with mathematical-inspired expectations?

--
A: Because it messes up the order in which people normally read text.
Q: Why is it such a bad thing?
A: Top-posting.
Q: What is the most annoying thing on usenet and in e-mail?
Mar 25 '07 #14

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"DirtyHarry" worte:
Good day everyone. This sounds like a stupid question, but I became
just curious yesterday, and I looked up several textbooks. However, no
textbooks on computer language (that I have ) mentioned this. So I am
asking to you, gurus...

Is there any particular reason to call 'float' instead of 'real'?
My guess is that it originated with the hardware designers. It seemed
descriptive so others that came along just adopted it.
My theory seems to be supported by this link.

http://www.oars.utk.edu/math_archive...pr99/0144.html
Mar 25 '07 #15

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Thanks, everyone... Finally I got out of clouds...
Mar 27 '07 #16

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Dnia Fri, 23 Mar 2007 21:59:12 -0700, Jim Langston napisał(a):
So if we call a float a real, does that mean we have to
call an int a fake?
unreal :>

--
SasQ
Mar 28 '07 #17

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