This is just as an update.

MakeProfiles and CosmicCalculator now also work with the new data structure and all the great new features it has offered (e.g., option management system and table reading/writing, and column selection). So in total 4 programs now work with this system (Arithmetic and Table were done before).

If you want to try it out, you can clone and bootstrap the datastruct branch on my development fork. In case you do, the easiest way is to configure and build is with the ./tmpfs-config-make script. It will have all the `--enable-programname' configure options until all the programs are ported.

With this infra-structure built and tested on these four programs, the rest of the work on porting the other programs should be done soon. If you do get the chance to try them out it would be great.

Its interesting that while the code has become much more readable and clear, from the last commit, the total number of line deletions became larger than the additions in this branch compared to the `master' branch. By the time all programs are ported, this difference will be much more larger. So the code is becoming much more elegant :-).

This is just an update.

A large number of functions have already been defined for this data structure, please see data.h. The fits.h functions have also been corrected (and greatly simplified) to return this data structure (for image arrays, header keywords, and I am working on table columns now).

Gnuastro's Arithmetic has been fully migrated to this new data structure, and as it currently stands, it is the only program that works as expected in this branch. The main work-horse behind arithmetic on this data structure is now a library, so library users can also benefit from them. Until now, Arithmetic would convert the input data to double type, do the arithmetic operations, then save the results in the desired type. When the data sets get large (>1Gb for example), this conversion itself consumes a large amount of CPU and memory resources. Thanks to this data structure, we arithmetic library functions will now do all the work on the native type of the data, so no conversion is necessary, and is a great step towards better performance.

So in case you want to compile/test this branch please configure Gnuastro with `--enable-arithmetic --enable-table' (the new FITS functions are now corrected in the other programs yet).

Just one note: to efficiently account for native arithmetic operations on all the combinations of the different data types (especially for the binary operators that need two operands), the only way I could come up with until now was heavy usage of macros, for example see data-arithmetic-binary.c.

These macros greatly help in efficient running of the binary arithmetic operators, but it will greatly lengthen the compilation time. For example, to allow all the types to be natively operated on, on my system with default configure options, the compilation will take about 20 minutes! So I have defined configure time options to specify which types to allow for native binary arithmetic (`--enable-bin-op-XXXX', where `XXXX' is the type name). If the data type is not native, it will be converted to a native type, the arithmetic will be done and the output will be set to the proper type. I have tried to fully describe this under these options in the "Configuring" subsection of the book. With the currently default native types, it takes about 2 minutes to compile by default. But if compilation time is very important for you, you can disable optimization and shared libraries (like in debugging mode) and compilation time will be like before (less than a minute).

I am now working on fully implementing Gnuastro's Table program to use this data structure. Reading of FITS tables has been implemented, and I am now working on the writing and also reading/writing of ASCII tables. Once table columns can also be easily read using this structure, most of the job will be done: since the inputs/outputs of the programs are either table columns or images/arrays.