strtod - Dynamic Memory?

[Marky C]

atof is not working.

double a = atof("12.345");

a gets set to 12.000

I am working on a toshiba micro. The data map has no space allocated
to it for dynamic memory.

Does anyone have an idea? Could it be due to the lack of dynamic
memmor space?

All thoughts gratefully received

Marky C

[Richard Bos]

eg*********@hot mail.com (Marky C) wrote:

atof is not working.

double a = atof("12.345");

a gets set to 12.000
That is not allowed, surely? 12.345 must be representable, albeit
possibly with a slight error, within a double. "12.345" is a valid
string representation of 12.345. Therefore, atof() _must_ convert
"12.345" to (double)12.345 plus-or-minus a slight error, which error is
certainly smaller than two decimals.
I am working on a toshiba micro. The data map has no space allocated
to it for dynamic memory.
The latter should be immaterial, but are you sure that this is a
complete hosted ISO C implementation, and not a freestanding one, or
even a non-ISO version?
Does anyone have an idea? Could it be due to the lack of dynamic
memmor space?

Shouldn't be.

Richard

[Leor Zolman]

On 1 Apr 2004 05:29:39 -0800, eg*********@hot mail.com (Marky C) wrote:

atof is not working.

double a = atof("12.345");

a gets set to 12.000

I am working on a toshiba micro. The data map has no space allocated
to it for dynamic memory.

Does anyone have an idea? Could it be due to the lack of dynamic
memmor space?
That's difficult to imagine. Are you sure you've included the appropriate
header file (math.h or stdlib.h)? If you'd have gotten 0 or some totally
random number instead of 12 into a, then forgetting to include the header
would have been a lot higher on my probability chart. But it is still a
possibility.

If that doesn't fix it, you may need to locate a group that knows more
specifics about your platform.
-leor

All thoughts gratefully received

Marky C

--
Leor Zolman --- BD Software --- www.bdsoft.com
On-Site Training in C/C++, Java, Perl and Unix
C++ users: Download BD Software's free STL Error Message Decryptor at:
www.bdsoft.com/tools/stlfilt.html

[Mike Wahler]

"Marky C" <eg*********@ho tmail.com> wrote in message
news:9e******** *************** ***@posting.goo gle.com...

atof is not working.

double a = atof("12.345");

a gets set to 12.000
If you're using a pre-C99 compiler, and failed
to provide a prototype for 'atof()' (by #including
<stdlib.h>), then the compiler will assume that 'atof()'
returns type 'int'. This fact will truncate the
fractional part of the return value before assigning
it to 'a'. If using a C99 compiler without providing
the prototype, you should have received a diagnostic.

I am working on a toshiba micro. The data map has no space allocated
to it for dynamic memory.
That shouldn't matter, as long as you're using a conforming
hosted implemenatation .

Does anyone have an idea? Could it be due to the lack of dynamic
memmor space?
Perhaps, but I doubt it.

All thoughts gratefully received

-Mike

[Dan Pop]

In <9e************ **************@ posting.google. com> eg*********@hot mail.com (Marky C) writes:

atof is not working.

double a = atof("12.345");

a gets set to 12.000
Did you consider including <stdlib.h> ?
I am working on a toshiba micro. The data map has no space allocated
to it for dynamic memory.

Does anyone have an idea? Could it be due to the lack of dynamic
memmor space?

Nope. Show us a complete program illustrating your problem.

Dan
--
Dan Pop
DESY Zeuthen, RZ group
Email: Da*****@ifh.de

[Peter Slootweg]

"Marky C" <eg*********@ho tmail.com> wrote in message
news:9e******** *************** ***@posting.goo gle.com...

atof is not working.

double a = atof("12.345");

a gets set to 12.000

I am working on a toshiba micro. The data map has no space allocated
to it for dynamic memory.

Does anyone have an idea? Could it be due to the lack of dynamic
memmor space?

All thoughts gratefully received

Marky C

First I'd check what everyone else suggested
i.e. did you include stdlib.h?
If you did then I'd confirm the locale you are using has '.' as the decimal
point

try the following ( assuming printf actually displays something on your
system)
#include <locale.h>
#include <stdio.h>

void PrintLocaleDeci mal(void)
{
struct lconv *lcp = localeconv();

printf("decimal ='%s'\n",
lcp->decimal_point) ;
}

[Fred L. Kleinschmidt]

Marky C wrote:

atof is not working.

double a = atof("12.345");

a gets set to 12.000

I am working on a toshiba micro. The data map has no space allocated
to it for dynamic memory.

Does anyone have an idea? Could it be due to the lack of dynamic
memmor space?

All thoughts gratefully received

Marky C

Did you #include <stdlib.h> ? If not, your compiler thinks the result of
the atof call is an int.

--
Fred L. Kleinschmidt
Boeing Associate Technical Fellow
Technical Architect, Common User Interface Services
M/S 2R-94 [phone]

[Malcolm]

"Mike Wahler" <mk******@mkwah ler.net> wrote in message

If you're using a pre-C99 compiler, and failed
to provide a prototype for 'atof()' (by #including
<stdlib.h>), then the compiler will assume that 'atof()'
returns type 'int'. This fact will truncate the
fractional part of the return value before assigning
it to 'a'.

That's not what normally happens. Generally the compiler interprets the
double as an integer, either grabbing bytes from the stack or reading from
the register used for integer returns, with garbage results.

[Martin Ambuhl]

Marky C wrote:

atof is not working.
Maybe, but more likely your code is wrong.
double a = atof("12.345");
a gets set to 12.000
This suggest atof is returning an int, which would be the default
assumption if atof were not prototyped. This suggests that you forgot
to #include <stdlib.h>
I am working on a toshiba micro. The data map has no space allocated
to it for dynamic memory.
Does anyone have an idea? Could it be due to the lack of dynamic
memmor space?
All that should be irrelevant. All thoughts gratefully received

Cut and paste the following _exactly_. Report your findings.

#include <stdlib.h>
#include <stdio.h>

int main(void)
{
double a = atof("12.345");
double b = strtod("12.345" , 0);
printf("a = %g, b = %g\n", a, b);
return 0;
}

[output should be]
a = 12.345, b = 12.345

[Dan Pop]

In <6c************ *************** *****@4ax.com> Leor Zolman <le**@bdsoft.co m> writes:

On 1 Apr 2004 05:29:39 -0800, eg*********@hot mail.com (Marky C) wrote:

atof is not working.

double a = atof("12.345");

a gets set to 12.000

I am working on a toshiba micro. The data map has no space allocated
to it for dynamic memory.

Does anyone have an idea? Could it be due to the lack of dynamic
memmor space?

That's difficult to imagine. Are you sure you've included the appropriate
header file (math.h or stdlib.h)? If you'd have gotten 0 or some totally

It's <stdlib.h> *only*. A <math.h> declaring atof would be broken.

Dan
--
Dan Pop
DESY Zeuthen, RZ group
Email: Da*****@ifh.de