Re: Fractions

2002-09-23 Thread Michael T. Babcock 

MySQL wrote:

   You might also consider using two integer type fields - one for the
   numerator and another for the denominator. This way storage and recovery are
   easy and the mathematics are wide open.
   _M

I suspect that a float add is faster than 3 integer multiplies and
sum.
  

It depends on why you're storing this information in the first place. 
 If what you want is the precision of fractions (which you lose with 
floating point), then store the numerator and denominator.  If you want 
quick and dirty calculations at certain points in your code, store both ...

Example (where $x, $y are variables):
INSERT INTO FracTable (numerator, denominator, appxval) values ($x, $y, 
$x/$y);

-- 
Michael T. Babcock
C.T.O., FibreSpeed Ltd.
http://www.fibrespeed.net/~mbabcock



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Re: Fractions

2002-09-22 Thread Jan Steinman 

From: MySQL [EMAIL PROTECTED]

   From: Madscientist [EMAIL PROTECTED]

   You might also consider using two integer type fields - one for the
   numerator and another for the denominator. This way storage and recovery are
   easy and the mathematics are wide open.
   _M

I suspect that a float add is faster than 3 integer multiplies and
sum.

Ah, but it is not as accurate!

If the original poster knows he needs fractions, he won't be happy with float.

Just as one should NEVER use floating point to represent money, one should NEVER use 
it for representing fractions that need to be precise. For example, (1/3 as a float) * 
3 will come out to 0..

-- 
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Re: Fractions

2002-09-20 Thread MySQL 

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   At 20:47 -0500 9/18/02, William Martell wrote:
   Hello.
   
   Can anyone tell me whether we can represent fractions in MySQL 4.0.  I have
   data representing different lengths of objects measured in inches.  Can I
   load this data as is into a field in MySQL or do I have to convert it first
   into an floating point interger or decimal value???

   You could store them as strings, but you'd have to interpret them on
   the client side, most likely.

In which case you might as well store them as reals, with char
substitution (interpret).  As reals, later when the inevitable desire
occurs to add different lengths, it will be simple.

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RE: Fractions

2002-09-20 Thread Madscientist 

You might also consider using two integer type fields - one for the
numerator and another for the denominator. This way storage and recovery are
easy and the mathematics are wide open.
_M

]-Original Message-
]From: MySQL [mailto:[EMAIL PROTECTED]]
]Sent: Thursday, September 19, 2002 7:51 PM
]To: [EMAIL PROTECTED]
]Cc: [EMAIL PROTECTED]; [EMAIL PROTECTED]
]Subject: Re: Fractions
]
]
]   Mailing-List: contact [EMAIL PROTECTED]; run by ezmlm
](http://www.ezmlm.org)
]   X-Sender: [EMAIL PROTECTED]@teton.kitebird.com
]   Date: Thu, 19 Sep 2002 08:54:55 -0500
]   From: Paul DuBois [EMAIL PROTECTED]
]   News-Group: list.mysql
]   Reply-To: [EMAIL PROTECTED]
]
]   At 20:47 -0500 9/18/02, William Martell wrote:
]   Hello.
]   
]   Can anyone tell me whether we can represent fractions in MySQL
]4.0.  I have
]   data representing different lengths of objects measured in
]inches.  Can I
]   load this data as is into a field in MySQL or do I have to
]convert it first
]   into an floating point interger or decimal value???
]
]   You could store them as strings, but you'd have to interpret them on
]   the client side, most likely.
]
]In which case you might as well store them as reals, with char
]substitution (interpret).  As reals, later when the inevitable desire
]occurs to add different lengths, it will be simple.
]
]-
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Re: Fractions

2002-09-20 Thread MySQL 

   From: Madscientist [EMAIL PROTECTED]
   Cc: [EMAIL PROTECTED]
   Date: Fri, 20 Sep 2002 08:26:21 -0400
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   You might also consider using two integer type fields - one for the
   numerator and another for the denominator. This way storage and recovery are
   easy and the mathematics are wide open.
   _M

I suspect that a float add is faster than 3 integer multiplies and
sum.


   ]-Original Message-
   ]From: MySQL [mailto:[EMAIL PROTECTED]]
   ]Sent: Thursday, September 19, 2002 7:51 PM
   ]To: [EMAIL PROTECTED]
   ]Cc: [EMAIL PROTECTED]; [EMAIL PROTECTED]
   ]Subject: Re: Fractions
   ]
   ]
   ]   Mailing-List: contact [EMAIL PROTECTED]; run by ezmlm
   ](http://www.ezmlm.org)
   ]   X-Sender: [EMAIL PROTECTED]@teton.kitebird.com
   ]   Date: Thu, 19 Sep 2002 08:54:55 -0500
   ]   From: Paul DuBois [EMAIL PROTECTED]
   ]   News-Group: list.mysql
   ]   Reply-To: [EMAIL PROTECTED]
   ]
   ]   At 20:47 -0500 9/18/02, William Martell wrote:
   ]   Hello.
   ]   
   ]   Can anyone tell me whether we can represent fractions in MySQL
   ]4.0.  I have
   ]   data representing different lengths of objects measured in
   ]inches.  Can I
   ]   load this data as is into a field in MySQL or do I have to
   ]convert it first
   ]   into an floating point interger or decimal value???
   ]
   ]   You could store them as strings, but you'd have to interpret them on
   ]   the client side, most likely.
   ]
   ]In which case you might as well store them as reals, with char
   ]substitution (interpret).  As reals, later when the inevitable desire
   ]occurs to add different lengths, it will be simple.

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Fractions

2002-09-19 Thread William Martell 

Hello.

Can anyone tell me whether we can represent fractions in MySQL 4.0.  I have
data representing different lengths of objects measured in inches.  Can I
load this data as is into a field in MySQL or do I have to convert it first
into an floating point interger or decimal value???

Thanks in advance.
William


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Re: Fractions

2002-09-19 Thread Paul DuBois 

At 20:47 -0500 9/18/02, William Martell wrote:
Hello.

Can anyone tell me whether we can represent fractions in MySQL 4.0.  I have
data representing different lengths of objects measured in inches.  Can I
load this data as is into a field in MySQL or do I have to convert it first
into an floating point interger or decimal value???

You could store them as strings, but you'd have to interpret them on
the client side, most likely.


Thanks in advance.
William


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Fractions

2002-09-19 Thread William Martell 

sql,query,database,odbc


Hello All,

Can anyone tell me whether I can represent fractions in MySQL 4.  I have
data representing different lengths of objects measured in inches.  Can I
load this data as is into a field in MySQL and still retain the same value
or do I have to convert it first to a float or decimal value??

What type of data type will the field be bigint, int, decimal???  The
measurements are small, for example 2 1/2 inches, 3 1/8 inches.

Thanks in advance


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Re: Fractions

2002-09-19 Thread David Patte 

you could store them as 3 integers. The integral part, the numerator of 
the fraction and the denominator of the fraction - then interpret them 
at the client side.


William Martell wrote:
 sql,query,database,odbc
 
 
 Hello All,
 
 Can anyone tell me whether I can represent fractions in MySQL 4.  I have
 data representing different lengths of objects measured in inches.  Can I
 load this data as is into a field in MySQL and still retain the same value
 or do I have to convert it first to a float or decimal value??
 
 What type of data type will the field be bigint, int, decimal???  The
 measurements are small, for example 2 1/2 inches, 3 1/8 inches.
 
 Thanks in advance


-- 
David Patte
Relative Data, Inc.
--
MyStars! 2.7 Shareware for Stargazers
Website #1: http://www.relativedata.com/
Website #2: http://www.mystarslive.com/
24 Hr Bus. Phone/Fax: 1 (613) 728-4240


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Re: Fractions

2002-09-19 Thread Thomas Spahni 

On Wed, 18 Sep 2002, William Martell wrote:

 Can anyone tell me whether we can represent fractions in MySQL 4.0.  I have
 data representing different lengths of objects measured in inches.  Can I
 load this data as is into a field in MySQL or do I have to convert it first
 into an floating point interger or decimal value???

Did you consider storing a fraction using 2 integers? That's the way we
did it many years ago in Forth.

Thomas Spahni
-- 
sql, query


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Re: Fractions

2002-09-19 Thread Michael T. Babcock 


[ this mysql spam filter sucks -- including a query in one's message 
isn't good enough ]

[EMAIL PROTECTED] wrote:

you could store them as 3 integers. The integral part, the numerator 
of the fraction and the denominator of the fraction - then interpret 
them at the client side.



This would even have the benefit of making the whole thing sortable 
(with approximations) ...

# val_i := integer; val_n := numerator; val_d := denominator
SELECT id FROM table WHERE val_i + (val_n / val_d)  10;

-- 
Michael T. Babcock
C.T.O., FibreSpeed Ltd.
http://www.fibrespeed.net/~mbabcock



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