XPost: sci.math.num-analysis   
   From: nospam@needed.invalid   
      
   On Mon, 2/23/2026 2:06 PM, David Brown wrote:   
      
   >>>>       (text version of PI)  100,000,022 bytes   
   >>>>       PI-Binary.bin          41,524,121 bytes   exponent   
   and limbs   
   >   
   > Weirdly (at least /I/ think it is weird), it is easier to calculate   
   hexadecimal digits of pi than decimal digits.   
      
   I computed the decimal representation and the hex representation   
   (by dumping the exponent and limbs), in the same run.   
      
   int mpf_out_raw (FILE *f, mpf_t X) {   
      int expt; mpz_t Z; size_t nz;   
      expt = X->_mp_exp;   
      fwrite(&expt, sizeof(int), 1, f);   
      nz = X->_mp_size;   
      Z->_mp_alloc = nz;   
      Z->_mp_size  = nz;   
      Z->_mp_d     = X->_mp_d;   
      return (mpz_out_raw(f, Z) + sizeof(int));   
   }   
      
   And that's called this way.   
      
     /* Open the destination file in binary write mode */   
     FILE *destination = fopen("PI-Binary.bin", "wb");   
     if (!destination) {   
           perror("Error opening PI-Binary.bin file");   
     } else {   
        mpf_out_raw(destination, qi); /* qi happens to hold 100 million digits of   
   PI */   
        fflush(destination);   
        fclose(destination);   
     }   
      
   You can do them in the same run.   
      
   The 7,7,7,7,7,7,7,7,2 sequence was detected in a 32 million digit run   
   of SuperPi 1.5 XS. The 100 million digit sequence is too large   
   for SuperPI, and pgmp-chudnovsky.c (with OpenMP) was   
   used for that, with a little extra code thrown in so I could get   
   the floating point storage in raw format. It takes a bit more   
   than one minute, to generate 100 million digits (16 cores). The   
   compression attempt was done on a single core, to ensure the best   
   attempt at compression with 7ZIP.   
      
   The order of the PI method O() used is covered here.   
      
   https://en.wikipedia.org/wiki/Chudnovsky_algorithm   
      
      Paul   
      
   --- SoupGate-Win32 v1.05   
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