I uploaded a first version of the source code for my implementation of the "trustworthy Julia sets algorithm" by Figueiredo et al.

https://github.com/marcm200/julia-tsa-core

The functionality is pretty simple for now, but images up to 2^18 pixel width have been generated by it:

• command line version
• generating a Julia set from scratch for the quadratic, cubic, quartic or pentic case.
• resuming computation from temporary raw data
• refinement simulation

EDIT: Nov 18, 2019: I changed the title to reflect that there are currently two different programs in this topic - polynomial 2D and the trivariate polynomial 3D one (reply #9).

Linkback: https://fractalforums.org/programming/11/true-shapeia-2d3d-julia-set-source-code/2930/

Yes, I will in a couple of days. I'm trying to understand the licensing of the tdm64 compiler I'm using and if I can just compile and upload the exe of my code or if there's more legal things to do beforehand.

I edited BATCH CREATION file to render an image, see the result:

@echo off
juliatsacore_quadratic_win32.exe 4096 -0.78 -0.05 2 6
copy _tsa_juliaset_Y00X00.bmp julia-tsa-core_19071501.bmp
pause

New version with added functionality (source and binaries):

https://github.com/marcm200/julia-tsa-core/releases

• detecting basins of attraction
• detecting periodicity and immediate basins of periodic points
• polynomials z^n+A*z+C for n=2..6 implemented in one binary
• binaries provided for C++ double, long double and __float128 precision
• seed value c can be used as a single value or a complex interval
• check for sufficient precision of data type under current screen width, formula, complex plane range

I don't think this set is computable in a trustworthy manner to show interior cells.

The seed value I found in wikibooks is c=-0.390837354761211+0.586641524321638*i (I suspect it's a truncated/rounded value).
Julia sets with specific c values are only computable here if the real and imaginary parts both are dyadic fractions due to the underlying datatype.  Is the exact seed such a rational p/2^n ?

If not or if it is irrational I could only compute a set-family using a small complex box interval around the c seed. However since the actual seed is on the boundary of the Mandelbrot set, I think any complex interval would encompass both interior and exterior of the Mset and hence the set-family will contain both Cantor dust sets without interior and sets with interior. So the TSA algorithm would never show black cells (black when using c as an interval is the intersection of all black regions (2013 paper by Figueiredo, page 7).

A complex plane region where the whole set for the exact value resides, would be computable - if that is sufficient for your purposes. The image below shows such an interval Julia set family at level 16 (trustworthily downscaled 16-fold).

c=( [-13114327..-13114324] + i* [19684422..19684425] ) *2^-25

Two tools for the TSA algorithm:

Tool: TSApredictor (works only for the 2D version)
Purpose: To predict a refinement level at which interior cells can be detected.
Code and binaries for win32, win64 at: https://github.com/marcm200/TSApredictor

For limitations of the fast prediction process, please see forum link and the above-linked README.

Tool: bitPrec
Purpose: For user-entered real-valued expressions (e.g. component functions of complex or triplex iterative polynomials), the tool analyzes which datatype (double, long double, float128) is needed at a specific refinement level to provide error-free computation.

Code and binaries for win32, win64 at: https://github.com/marcm200/bitPrec

The command-line parser is very simple (variables and numbers are only one-digit/character, so 12*x must be written as 6*x+6*x, no unary operator, bracket-free expression) (detailed description in README in above link).

Below is an example output for a cubic complex polynomial:

z^3+A*z+c == (x+i*y)^3 + (f+g*i)*(x+i*y) + (d+e*i)

|re(C)=d|<=2,|im(C)=e|<=2
|re(A)=f|<=2,|im(A)=g|<=2
|x|<=4,|y|<=4

axisrange = -4 .. +4
SCALE := (2*axis range) / (2^REFINEMENT LEVEL == pixels per axis)
  := 2^-(REF-3)

notation: e.g. 3.21 = 24
  3 bits for the integer part
 21 bits for the fractional part
 24 total bits


===============================================================
|real z_new| <=
                 |d| ||maxw=  2 2.0 .25
             + |f*x| ||maxw=  8 4.0 (.25)+(.(SCALE))
             + |g*y| ||maxw=  8 4.0 (.25)+(.(SCALE))
             + |x^3| ||maxw= 64 7.0 3*(.(SCALE))
     + |3*(x*(y^2))| ||maxw=192 8.0 (.0)+((.(SCALE))+(2*(.(SCALE))))
-----------------------------------------------------------
                ||maxw=274 9.0 max(.25,(.25)+(.(SCALE)),3*(.(SCALE)),(.0)+((.(SCALE))+(2*(.(SCALE)))))

REF 10 9.32 = 41 => double
REF 11 9.33 = 42 => double
REF 12 9.34 = 43 => double
REF 13 9.35 = 44 => double
REF 14 9.36 = 45 => double
REF 15 9.37 = 46 => double
REF 16 9.39 = 48 => double
REF 17 9.42 = 51 => double
REF 18 9.45 = 54 => long double
REF 19 9.48 = 57 => long double
REF 20 9.51 = 60 => long double
REF 21 9.54 = 63 => float128
REF 22 9.57 = 66 => float128
REF 23 9.60 = 69 => float128
REF 24 9.63 = 72 => float128

===============================================================
|imag z_new| <=
                 |e| ||maxw=  2 2.0 .25
             + |f*y| ||maxw=  8 4.0 (.25)+(.(SCALE))
             + |g*x| ||maxw=  8 4.0 (.25)+(.(SCALE))
     + |3*((x^2)*y)| ||maxw=192 8.0 (.0)+((2*(.(SCALE)))+(.(SCALE)))
             + |y^3| ||maxw= 64 7.0 3*(.(SCALE))
-----------------------------------------------------------
                ||maxw=274 9.0 max(.25,(.25)+(.(SCALE)),(.0)+((2*(.(SCALE)))+(.(SCALE))),3*(.(SCALE)))

REF 10 9.32 = 41 => double
REF 11 9.33 = 42 => double
REF 12 9.34 = 43 => double
REF 13 9.35 = 44 => double
REF 14 9.36 = 45 => double
REF 15 9.37 = 46 => double
REF 16 9.39 = 48 => double
REF 17 9.42 = 51 => double
REF 18 9.45 = 54 => long double
REF 19 9.48 = 57 => long double
REF 20 9.51 = 60 => long double
REF 21 9.54 = 63 => float128
REF 22 9.57 = 66 => float128
REF 23 9.60 = 69 => float128
REF 24 9.63 = 72 => float128


New release (1.1.0) of juliatsa3dcore.

https://github.com/marcm200/juliatsa3d-core/releases

Performance improvements:

• reduced number of bounding box calculations (split color propagation)
• reduced memory transfer to cache (low-resolution reverse cell graph)
• support for Robert Munafo's fast double-double f107 datatype
• optimized calculation path for __float128 and f107 bbx calculations in some formulas
• faster internal viewer to create final 2D image
• some new formulas added (names SHnn)

(I changed the topic's title to "true shape/IA" as I think the former title was too ambiguous).

I can compile it and run on Ubuntu:

g++ main.cpp -Wall
main.cpp:1001:45: warning: overflow in conversion from ‘__clock_t’ {aka ‘long int’} to ‘int32_t’ {aka ‘int’} changes value from ‘7200000000’ to ‘-1389934592’ [-Woverflow]
 1001 | int32_t CLOCKHOURSTOSAVE=CLOCKS_PER_SEC*3600*2;
      |                                             ^
main.cpp: In member function ‘int32_t Data5::readRawBlowUp()’:
main.cpp:1587:18: warning: format ‘%d’ expects argument of type ‘int’, but argument 2 has type ‘int64_t’ {aka ‘long int’} [-Wformat=]
 1587 |  printf("\n  %I64d GB cell memory allocated\n",1+(memused >> 30));
      |              ~~~~^                             ~~~~~~~~~~~~~~~~~
      |                  |                              |
      |                  int                            int64_t {aka long int}
      |              %I64ld
main.cpp: In function ‘int color_changeS32(DDBYTE, DDBYTE, DDBYTE, DDBYTE)’:
main.cpp:5407:12: warning: comparison of integer expressions of different signedness: ‘int32_t’ {aka ‘int’} and ‘const DDBYTE’ {aka ‘const unsigned int’} [-Wsign-compare]
 5407 |      if (f == source1) {
      |          ~~^~~~~~~~~~
main.cpp: In function ‘char* seedCstr225(char*)’:
main.cpp:5568:24: warning: format ‘%d’ expects argument of type ‘int’, but argument 3 has type ‘int64_t’ {aka ‘long int’} [-Wformat=]
 5568 |  sprintf(erg,"c_ia_%I64d_%I64d_x_%I64d_%I64d",
      |                    ~~~~^
      |                        |
      |                        int
      |                    %I64ld
 5569 |   (int64_t)floor(DENOM225*(double)seedC0re),
      |   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      |   |
      |   int64_t {aka long int}
main.cpp:5568:30: warning: format ‘%d’ expects argument of type ‘int’, but argument 4 has type ‘int64_t’ {aka ‘long int’} [-Wformat=]
 5568 |  sprintf(erg,"c_ia_%I64d_%I64d_x_%I64d_%I64d",
      |                          ~~~~^
      |                              |
      |                              int
      |                          %I64ld
 5569 |   (int64_t)floor(DENOM225*(double)seedC0re),
 5570 |   (int64_t)floor(DENOM225*(double)seedC1re),
      |   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      |   |
      |   int64_t {aka long int}
main.cpp:5568:38: warning: format ‘%d’ expects argument of type ‘int’, but argument 5 has type ‘int64_t’ {aka ‘long int’} [-Wformat=]
 5568 |  sprintf(erg,"c_ia_%I64d_%I64d_x_%I64d_%I64d",
      |                                  ~~~~^
      |                                      |
      |                                      int
      |                                  %I64ld
......
 5571 |   (int64_t)floor(DENOM225*(double)seedC0im),
      |   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      |   |
      |   int64_t {aka long int}
main.cpp:5568:44: warning: format ‘%d’ expects argument of type ‘int’, but argument 6 has type ‘int64_t’ {aka ‘long int’} [-Wformat=]
 5568 |  sprintf(erg,"c_ia_%I64d_%I64d_x_%I64d_%I64d",
      |                                        ~~~~^
      |                                            |
      |                                            int
      |                                        %I64ld
......
 5572 |   (int64_t)floor(DENOM225*(double)seedC1im)
      |   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      |   |
      |   int64_t {aka long int}
main.cpp: In function ‘char* FAKTORAstr225(char*)’:
main.cpp:5587:21: warning: format ‘%d’ expects argument of type ‘int’, but argument 3 has type ‘int64_t’ {aka ‘long int’} [-Wformat=]
 5587 |  sprintf(erg,"A_%I64d_%I64d",
      |                 ~~~~^
      |                     |
      |                     int
      |                 %I64ld
 5588 |   (int64_t)floor(DENOM225*(double)FAKTORAre),
      |   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      |   |
      |   int64_t {aka long int}
main.cpp:5587:27: warning: format ‘%d’ expects argument of type ‘int’, but argument 4 has type ‘int64_t’ {aka ‘long int’} [-Wformat=]
 5587 |  sprintf(erg,"A_%I64d_%I64d",
      |                       ~~~~^
      |                           |
      |                           int
      |                       %I64ld
 5588 |   (int64_t)floor(DENOM225*(double)FAKTORAre),
 5589 |   (int64_t)floor(DENOM225*(double)FAKTORAim)
      |   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      |   |
      |   int64_t {aka long int}
main.cpp: In function ‘void periodicity_m3(char*)’:
main.cpp:5683:18: warning: format ‘%d’ expects argument of type ‘int’, but argument 2 has type ‘int64_t’ {aka ‘long int’} [-Wformat=]
 5683 |  printf("\n  %I64d reference points identified\n",refpointsctr);
      |              ~~~~^                                ~~~~~~~~~~~~
      |                  |                                |
      |                  int                              int64_t {aka long int}
      |              %I64ld
main.cpp:6183:15: warning: comparison of integer expressions of different signedness: ‘int32_t’ {aka ‘int’} and ‘uint32_t’ {aka ‘unsigned int’} [-Wsign-compare]
 6183 |    if (finalf != SQUARE_VISITED) {
      |        ~~~~~~~^~~~~~~~~~~~~~~~~
main.cpp: In function ‘void periodicity(char*)’:
main.cpp:6311:40: warning: format ‘%d’ expects argument of type ‘int’, but argument 2 has type ‘int64_t’ {aka ‘long int’} [-Wformat=]
 6311 |  printf("\nperiodicity memory used %I64d GB\n",1+(memused >> 30));
      |                                    ~~~~^       ~~~~~~~~~~~~~~~~~
      |                                        |        |
      |                                        int      int64_t {aka long int}
      |                                    %I64ld
main.cpp:6480:14: warning: format ‘%d’ expects argument of type ‘int’, but argument 4 has type ‘int64_t’ {aka ‘long int’} [-Wformat=]
 6480 |      LOGMSG3("Implementation error. new blob#%i, but list with %I64d elements\n",anzfatouinorbit,anzliste);
      |              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~                 ~~~~~~~~
      |                                                                                                  |
      |                                                                                                  int64_t {aka long int}
main.cpp:1236:15: note: in definition of macro ‘LOGMSG3’
 1236 |  fprintf(flog,TT,AA,BB); fflush(flog);\
      |               ^~
main.cpp:6480:68: note: format string is defined here
 6480 | OGMSG3("Implementation error. new blob#%i, but list with %I64d elements\n",anzfatouinorbit,anzliste);
      |                                                          ~~~~^
      |                                                              |
      |                                                              int
      |                                                          %I64ld
main.cpp:6480:14: warning: format ‘%d’ expects argument of type ‘int’, but argument 3 has type ‘int64_t’ {aka ‘long int’} [-Wformat=]
 6480 |      LOGMSG3("Implementation error. new blob#%i, but list with %I64d elements\n",anzfatouinorbit,anzliste);
      |              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~                 ~~~~~~~~
      |                                                                                                  |
      |                                                                                                  int64_t {aka long int}
main.cpp:1237:9: note: in definition of macro ‘LOGMSG3’
 1237 |  printf(TT,AA,BB);\
      |         ^~
main.cpp:6480:68: note: format string is defined here
 6480 | OGMSG3("Implementation error. new blob#%i, but list with %I64d elements\n",anzfatouinorbit,anzliste);
      |                                                          ~~~~^
      |                                                              |
      |                                                              int
      |                                                          %I64ld
main.cpp:6516:15: warning: format ‘%d’ expects argument of type ‘int’, but argument 3 has type ‘int64_t’ {aka ‘long int’} [-Wformat=]
 6516 |       LOGMSG2("Implementation error. list mistake %I64d elements, 0 expected\n",anzliste);
      |               ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~
      |                                                                                 |
      |                                                                                 int64_t {aka long int}
main.cpp:1230:15: note: in definition of macro ‘LOGMSG2’
 1230 |  fprintf(flog,TT,AA); fflush(flog);\
      |               ^~
main.cpp:6516:55: note: format string is defined here
 6516 |       LOGMSG2("Implementation error. list mistake %I64d elements, 0 expected\n",anzliste);
      |                                                   ~~~~^
      |                                                       |
      |                                                       int
      |                                                   %I64ld
main.cpp:6516:15: warning: format ‘%d’ expects argument of type ‘int’, but argument 2 has type ‘int64_t’ {aka ‘long int’} [-Wformat=]
 6516 |       LOGMSG2("Implementation error. list mistake %I64d elements, 0 expected\n",anzliste);
      |               ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~
      |                                                                                 |
      |                                                                                 int64_t {aka long int}
main.cpp:1231:9: note: in definition of macro ‘LOGMSG2’
 1231 |  printf(TT,AA);\
      |         ^~
main.cpp:6516:55: note: format string is defined here
 6516 |       LOGMSG2("Implementation error. list mistake %I64d elements, 0 expected\n",anzliste);
      |                                                   ~~~~^
      |                                                       |
      |                                                       int
      |                                                   %I64ld
main.cpp:6797:14: warning: unused variable ‘PP_FLAGS’ [-Wunused-variable]
 6797 |  const DBYTE PP_FLAGS         =0b1110000000000000;
      |              ^~~~~~~~
main.cpp:6801:14: warning: unused variable ‘PP_UN_VISITED’ [-Wunused-variable]
 6801 |  const DBYTE PP_UN_VISITED    =0b1011111111111111;
      |              ^~~~~~~~~~~~~
main.cpp:6803:14: warning: unused variable ‘PP_UN_POSSIBLEPER’ [-Wunused-variable]
 6803 |  const DBYTE PP_UN_POSSIBLEPER=0b1101111111111111;
      |              ^~~~~~~~~~~~~~~~~
main.cpp: In member function ‘void Data5::precomputeScreenRect()’:
main.cpp:10608:20: warning: format ‘%d’ expects argument of type ‘int’, but argument 2 has type ‘int64_t’ {aka ‘long int’} [-Wformat=]
10608 |  printf(" used %I64d GB\n",
      |                ~~~~^
      |                    |
      |                    int
      |                %I64ld
10609 |   (memoryused >> 30)+1);
      |   ~~~~~~~~~~~~~~~~~~~~
      |                     |
      |                     int64_t {aka long int}
main.cpp: In function ‘int32_t main(int32_t, char**)’:
main.cpp:11047:10: warning: format ‘%d’ expects argument of type ‘int’, but argument 3 has type ‘int64_t’ {aka ‘long int’} [-Wformat=]
11047 |  LOGMSG2("%I64d bounding boxes calculated\n",ctrbbxfa);
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~
      |                                              |
      |                                              int64_t {aka long int}
main.cpp:1230:15: note: in definition of macro ‘LOGMSG2’
 1230 |  fprintf(flog,TT,AA); fflush(flog);\
      |               ^~
main.cpp:11047:15: note: format string is defined here
11047 |  LOGMSG2("%I64d bounding boxes calculated\n",ctrbbxfa);
      |           ~~~~^
      |               |
      |               int
      |           %I64ld
main.cpp:11047:10: warning: format ‘%d’ expects argument of type ‘int’, but argument 2 has type ‘int64_t’ {aka ‘long int’} [-Wformat=]
11047 |  LOGMSG2("%I64d bounding boxes calculated\n",ctrbbxfa);
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~
      |                                              |
      |                                              int64_t {aka long int}
main.cpp:1231:9: note: in definition of macro ‘LOGMSG2’
 1231 |  printf(TT,AA);\
      |         ^~
main.cpp:11047:15: note: format string is defined here
11047 |  LOGMSG2("%I64d bounding boxes calculated\n",ctrbbxfa);
      |           ~~~~^
      |               |
      |               int
      |           %I64ld
a@zalman:~/julia-tsa-core$ ls
a.out  _bit_requirements_per_function.zip  _juliasets.gif  LICENSE  main.cpp  _periodic_points_basilica.bat  README.md
a@zalman:~/julia-tsa-core$ ./a.out
juliatsacoredyn
file principal part _L10__z2c_c_ia_-1_-1_x_0_0.bmp
initialising main object ...
No stored data found. Computation starts anew.
searching for special exterior ... x1024 768 512 256   roughly -2..2 x -2..2 used
precomputing sub-expressions ... Y X

counting parents ...
setting parents to squares ... x
propagating definite color ... 944 432
propagating definite color ... 800 288
propagating definite color ... 656
propagating definite color ... 1024 512
propagating definite color ... 880 368
propagating definite color ... 736 224
propagating definite color ... 592
propagating definite color ... 960 448
propagating definite color ... 816 304
propagating definite color ... 672 160
propagating definite color ... 528 saving raw data ... done

propagating potentially white ... 1024 768 512 256
propagating potentially white ... 880 624 368
propagating potentially white ... 992 736 480 224
propagating potentially white ... 848 592 336
propagating potentially white ... 960 704 448 192
propagating potentially white ... 816 560 304
propagating potentially white ... 928 672 416 160
propagating potentially white ... 784 528 272
propagating potentially white ... 896 640 384
propagating potentially white ... 1008 752 496 240
propagating potentially white ... 864 608 352
propagating potentially white ... 976 720 464 208
propagating potentially white ... 832 576 320
propagating potentially white ... 944 688 432 176
searching for interior cells ... 1024 896 768 640 512 384 256 128
INTERIOR present
saving raw data ... done

saving image ... freeing non-image memory ...

duration 0 sec
                                                         1417453 bounding boxes calculated