I see. One problem here is that I don't know in advance the size of the returned list, so the allocation should happen in the c++ library side. So I am guessing the way around it is to return a pointer to the mpfr_ptr. Right?
El domingo, 5 de febrero de 2017, 11:43:54 (UTC+1), vdelecroix escribió: > > If you want to be complient with GMP/MPFR/FLINT you should change the > signature of > > mpfr_t* my_function (mpfr_t *_coef) > > to > > void my_function(mfpr_ptr result, mpfr_ptr input, slong len) > > And such function should not do any allocation at all. > > Le 05/02/2017 à 11:40, Vincent Delecroix a écrit : > > If you had a look at the code I provided you can check that what you did > > is very wrong. > > > > mpfr_t is already an array. The type "mpfr_t * x" make no sense at all. > > > > Le 05/02/2017 à 11:38, mmarco a écrit : > >> I am afraid I didn't explain my problem well enough. > >> > >> My problem is not to write c++ code with mpfr. That is solved > >> It is also not to call c++ libraries from cython code that involves > plain > >> mpfr numbers. That is also solved. > >> My problem is to do so with functions that involve *arrays *(or lists, > or > >> vectors) of mpfr numbers. > >> > >> In particular, assume that i have writen a c++ library that provides a > >> function my_function that takes an array of mpfr numbers and returns > >> another array of mpfr numbers. So I try to write some cython code to > >> interface in from sage: > >> > >> #clang C++ > >> #clib my_library > >> > >> > >> include 'cysignals/signals.pxi' > >> > >> > >> from sage.libs.mpfr cimport * > >> from sage.rings.real_mpfr cimport RealNumber > >> from sage.rings.real_mpfr import RealField > >> > >> > >> cdef extern from "my_library.h": > >> mpfr_t* my_function (mpfr_t *_coef) > >> > >> > >> def my_cython_function(values): > >> cdef mpfr_t* cvalues = <mpfr_t*> > >> sage_malloc(sizeof(mpfr_t)*len(values)) > >> cdef mpfr_t tempnum > >> cdef mpfr_t* rop > >> for i,v in enumerate(values): > >> tempnum = values[i].value > >> mpfr_init(cvalues[i]) > >> mpfr_set(cvalues[i], tempnum, MPFR_RNDN) > >> sig_on > >> rop = my_function(cvalues) > >> sig_off > >> > >> > >> This code is suppopsed to just create an array of mpfr objects to be > >> passed > >> to my_function, and another array to get the result of that function. > >> When > >> I try to compile it I get the following error: > >> > >> > >> > --------------------------------------------------------------------------- > >> > >> UnicodeDecodeError Traceback (most recent call > >> last) > >> /home/mmarco/sage/local/lib/python2.7/site-packages/IPython/core/ > >> interactiveshell.pyc in run_code(self, code_obj, result) > >> 2896 if result is not None: > >> 2897 result.error_in_exec = sys.exc_info()[1] > >> -> 2898 self.showtraceback() > >> 2899 else: > >> 2900 outflag = 0 > >> > >> /home/mmarco/sage/local/lib/python2.7/site-packages/IPython/core/ > >> interactiveshell.pyc in showtraceback(self, exc_tuple, filename, > >> tb_offset, > >> exception_only) > >> 1822 except Exception: > >> 1823 stb = self.InteractiveTB. > >> structured_traceback(etype, > >> -> 1824 value, tb, > tb_offset= > >> tb_offset) > >> 1825 > >> > >> > >> 1826 self._showtraceback(etype, value, stb) > >> > >> > /home/mmarco/sage/local/lib/python2.7/site-packages/IPython/core/ultratb.pyc > > >> > >> in structured_traceback(self, etype, value, tb, tb_offset, > >> number_of_lines_of_context) > >> 1404 self.tb = tb > >> 1405 return FormattedTB.structured_traceback( > >> -> 1406 self, etype, value, tb, tb_offset, > >> number_of_lines_of_context) > >> 1407 > >> > >> > >> 1408 > >> > >> > /home/mmarco/sage/local/lib/python2.7/site-packages/IPython/core/ultratb.pyc > > >> > >> in structured_traceback(self, etype, value, tb, tb_offset, > >> number_of_lines_of_context) > >> 1312 # Verbose modes need a full traceback > >> 1313 return VerboseTB.structured_traceback( > >> -> 1314 self, etype, value, tb, tb_offset, > >> number_of_lines_of_context > >> 1315 ) > >> 1316 else: > >> > >> > /home/mmarco/sage/local/lib/python2.7/site-packages/IPython/core/ultratb.pyc > > >> > >> in structured_traceback(self, etype, evalue, etb, tb_offset, > >> number_of_lines_of_context) > >> 1162 > >> 1163 formatted_exception = > >> self.format_exception_as_a_whole(etype > >> , evalue, etb, number_of_lines_of_context, > >> -> 1164 > >> tb_offset) > >> 1165 > >> > >> > >> 1166 colors = self.Colors # just a shorthand + quicker name > >> lookup > >> > >> > /home/mmarco/sage/local/lib/python2.7/site-packages/IPython/core/ultratb.pyc > > >> > >> in format_exception_as_a_whole(self, etype, evalue, etb, > >> number_of_lines_of_context, tb_offset) > >> 1111 return "" > >> 1112 > >> -> 1113 last_unique, recursion_repeat = > >> find_recursion(orig_etype, > >> evalue, records) > >> 1114 > >> 1115 frames = self.format_records(records, last_unique, > >> recursion_repeat) > >> > >> > /home/mmarco/sage/local/lib/python2.7/site-packages/IPython/core/ultratb.pyc > > >> > >> in find_recursion(etype, value, records) > >> 453 # quarter of the traceback (250 frames by default) is > >> repeats, > >> and find the > >> 454 # first frame (from in to out) that looks different. > >> --> 455 if not is_recursion_error(etype, value, records): > >> 456 return len(records), 0 > >> 457 > >> > >> > /home/mmarco/sage/local/lib/python2.7/site-packages/IPython/core/ultratb.pyc > > >> > >> in is_recursion_error(etype, value, records) > >> 439 # a recursion error. > >> 440 return (etype is recursion_error_type) \ > >> --> 441 and "recursion" in str(value).lower() \ > >> 442 and len(records) > 500 > >> 443 > >> > >> UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position > >> 1158: > >> ordinal not in range(128) > >> > >> > >> > >> > >> I tried to circunvent this problem by using c++ vectors instead of > >> malloc'ed arrays, but then it is the c++ compilet which complains abput > >> creating vectors of mpfr_t objects. > >> > >> Thoughts? > >> > -- You received this message because you are subscribed to the Google Groups "sage-devel" group. 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