Real to Int mathmatically (not fix)

I am not using this in lisp but I figured this would be the place to
ask.

Is there a math equation that will return an integer from an unknown
real?

--
Ken Alexander
Acad2004
Windows XP

"We can't solve problems by using the same kind
of thinking we used when we created them."
--Albert Einstein

 

Hi Ken,

Do you mean:
If UnknownObject is a real then return 1, if not return 0 ?
or
can you strip the decimal portion of the number leaving the digit part only
?
or
can you round the number to the nearest whole number ?

The answer to all three is yes, but to allow readers to tell you how you
need to clarify the question.


Laurie Comerford
CADApps
www.cadapps.com.au

 

You have N=a.b (275.6833) and you want a or b (275 or 6833)?

All programming languages (including vlisp) have at least one such
function. What you want, I think, is an algebraic method. No can do,
sorry. If you get into infinite series you can write a function that
will limit to a or b. Alternatively, you can state "N mod a = b" and
quiet any party.

rs

 

Hi Laurie,

Yes, I need to strip the decimal portion leaving an integer. This
needs to be done with a math equation not a programming function.

Thanks,

--
Ken Alexander
Acad2004
Windows XP

"We can't solve problems by using the same kind
of thinking we used when we created them."
--Albert Einstein

 

Hi Ken,

i would write it in this way:

int (a) = a - (a mod 1)

bob.at

 

Ken

(defun MyInt (Val)
(fix (- Val (rem Val 1)))
)

Cheers

 

(Hey,Ken! Long time since we passed notes!)

Look for the Greatest Possible Integer... by definition, drops anything
beyond the decimal.
Since this is a real simple operation, someone must have done it in LISP by
now.

(I'd try Jurg's code... he has helped me a bit in the past... and that's not
to say other contributions here don't work... just I haven't time to test
and render opinion)

regards!

 

Bob,

"Mod" was the ticket, Thanks a bunch.


--
Ken Alexander
Acad2004
Windows XP

"We can't solve problems by using the same kind
of thinking we used when we created them."
--Albert Einstein

 

You are satisfied -- which is the bottom line.

But, a little demurrer, "mod" is not an algebraic process, so the
question "Is there a math equation that will return an integer from an
unknown real?" is not really satisfied. In other words, x=3 mod 2 cannot
be solved by algebraic means.

rs

 

It looks as though I have not have worded my needs correctly.
I've never heard of mod before today. So happens it fulfilled my
needs for today. I'm sure there will be more later.

Thanks for taking the time to respond to all.

--
Ken Alexander
Acad2004
Windows XP

"We can't solve problems by using the same kind
of thinking we used when we created them."
--Albert Einstein