Hi,
Well, NetCDF specifies default fill values for all data types, so the most
compliant solution is to one of those. Although I realise that this comment is
off post.
Cheers,
Nick.
Please consider email bloat when replying to this email ;-)
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-------- Original Message --------
On 22/04/2025 04:15, Ryo Furue wrote:
> Chris,
>
>>> Having said that, NaN is usually "safer" in that its use causes error,
>>> making your bugs easier to spot.
>>
>> agreed, I like NaN as a fill value, but there's a downside -- NaN dpes not
>> equal NaN, so code that does:
>>
>> if something == fill_value:
>>
>> Will not work. It can be tricky.
>
> That's exactly the reason for the "isnan()" function:
>
>> if (isnan(fill_value)) . . .
>
> The Fortran language also includes such a function as part of its language
> standard:
>
>> use:: ieee_arithmetic
>>
>> if (ieee_is_nan(fill_value)) then
>> . . .
>
> In addition, Fortran compilers tend to include a compile option to enable
> "floating-point exception traps". If you enable the "invalid value" trap at
> the compile time, at the runtime, the program stops with an error message as
> soon as a NaN is generated or operated upon. This sometimes helps debug your
> code.
>
> Ryo
