Re: st: Mata buffered read 64-bit integer (8 byte/int64), how?

[Stas Kolenikov <skolenik@gmail.com>]

I guess at least a part of Sergiy's question is, "Can the mere mortals
like himself use the quad type that is obviously out there in Mata, as
all of the -quadsum()- and the like functions provide at least some
interface to this type?"


-- Stas Kolenikov, PhD, PStat (SSC)
-- Senior Survey Statistician, Abt SRBI
-- Opinions stated in this email are mine only, and do not reflect the
position of my employer
-- http://stas.kolenikov.name



On Thu, Jun 13, 2013 at 3:55 PM, Sergiy Radyakin <serjradyakin@gmail.com> wrote:
> Thank you, Stas,
> this is what I am doing now. Storage in a struct (or in my case simply
> in two real variables) is not a problem. The problem starts when you
> need one (LARGE) value, then x=x1*2^32+x2 becomes already lossy, since
> (as the manual says) : "Doubles can store up to 9,007,199,254,740,991
> exactly". Not that I would expect anyone to have files that big :)
> but formally I want to be on the safe side and I didn't expect a
> problem having 64-bit integers in (at least) 64-bit Stata.
>
> Sergiy
>
> On Thu, Jun 13, 2013 at 4:48 PM, Stas Kolenikov <skolenik@gmail.com> wrote:
>> You can probably define the -struct-ure that could store such strings,
>> and convert them into numbers for arithmetic operations. Bill Gould
>> may have had an article on this in Stata Journal -- the generic use of
>> structures is described in
>> http://www.stata-journal.com/sjpdf.html?articlenum=pr0035. Coding
>> matrix multiplication with these elements will quickly become an
>> overkill :-\.
>>
>> -- Stas Kolenikov, PhD, PStat (SSC)
>> -- Senior Survey Statistician, Abt SRBI
>> -- Opinions stated in this email are mine only, and do not reflect the
>> position of my employer
>> -- http://stas.kolenikov.name
>>
>>
>>
>> On Thu, Jun 13, 2013 at 3:12 PM, Sergiy Radyakin <serjradyakin@gmail.com> wrote:
>>> I read a 32-bit integer value from a buffered file with d=fbufget(C,fh,"%4bu").
>>>
>>> How do I read a 64-bit integer from the same file when Mata does not
>>> support format "%8bu"? And what can be the type of the LHS (type of
>>> variable d above) to accommodate the result of the read without the
>>> loss of information (double is not good, not sure about quad
>>> precision).
>>>
>>> I can read it as 8-bytes string, or 8 individual bytes, but I also
>>> need to work with the result as a value in Mata. So looking for a
>>> convenient solution.
>>>
>>> Thank you,
>>>      Sergiy
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