suprdewd / jay

Given initial terms of an unknown generating function F, conjecture a functional equation that F satisfies.

jay

A simple utility that, given some initial terms of an unknown generating function F, conjectures a functional equation that F satisfies. Inspired by this talk by Jay Pantone.

Synopsis

Usage: jay [OPTION]...
Given initial terms of an unknown generating function F,
conjecture a functional equation that F satisfies.

  -D,  --diff        the highest derivative of F to appear (default: 0)
  -fd, --fdeg        the highest power of F to appear (default: 1)
  -d,  --deg         the highest powers of variables to appear
  -t,  --type        the type of the generating function: ogf, egf (default: ogf)
       --hops        generate output that HOPS understands
  -h,  --help        display this help and exit
  -q,  --quiet       don't log any unnecessary output

The program expects the initial terms to be specified on standard
input in the following format. On the first line an integer 'n',
denoting the number of variables in the generating function. On
each of the following lines, until EOF, one initial term must be
specified in the format 'i_1 i_2 ... i_n c_{i_1, i_2, ..., i_n}',
meaning that 'c_{i_1, i_2, ..., i_n}' is the coefficient of
'x_1^{i_1} x_2^{i_2} ... x_n^{i_n}' in F. The list of initial terms
must be closed down, meaning that if a coefficient is listed, then
all coefficients with smaller indices must be listed as well.

Installing

$ ./autogen.sh
$ ./configure
$ make
# make install

Or, using the Nix package manager:

$ nix-env -f ./default.nix -i

License

MIT: see the LICENSE file.

jay's Issues

Can't compile on Ubuntu

Using: Ubuntu 16.04.3 LTS and gcc version 5.4.0 20160609

Making all in src
make[1]: Entering directory '/home/jay/jay/src'
depbase=`echo jay.o | sed 's|[^/]*$|.deps/&|;s|\.o$||'`;\
g++ -DPACKAGE_NAME=\"jay\" -DPACKAGE_TARNAME=\"jay\" -DPACKAGE_VERSION=\"0.1\" -DPACKAGE_STRING=\"jay\ 0.1\" -DPACKAGE_BUGREPORT=\"[email protected]\" -DPACKAGE_URL=\"\" -DPACKAGE=\"jay\" -DVERSION=\"0.1\" -DSTDC_HEADERS=1 -DHAVE_SYS_TYPES_H=1 -DHAVE_SYS_STAT_H=1 -DHAVE_STDLIB_H=1 -DHAVE_STRING_H=1 -DHAVE_MEMORY_H=1 -DHAVE_STRINGS_H=1 -DHAVE_INTTYPES_H=1 -DHAVE_STDINT_H=1 -DHAVE_UNISTD_H=1 -DHAVE_GMP_H=1 -DHAVE_LIBGMPXX=1 -I.     -g -O2 -std=c++0x -MT jay.o -MD -MP -MF $depbase.Tpo -c -o jay.o jay.cpp &&\
mv -f $depbase.Tpo $depbase.Po
g++  -g -O2 -std=c++0x   -o jay jay.o  -lgmpxx
/usr/bin/ld: jay.o: undefined reference to symbol '__gmpq_mul'
//usr/lib/x86_64-linux-gnu/libgmp.so.10: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status
Makefile:331: recipe for target 'jay' failed
make[1]: *** [jay] Error 1
make[1]: Leaving directory '/home/jay/jay/src'
Makefile:336: recipe for target 'all-recursive' failed
make: *** [all-recursive] Error 1```

Make HOPS output actually work in HOPS

HOPS needs the output to be of the form F=something. Try to rearrange the output in that way, when possible.

Higher order derivatives shown incorrectly in HOPS output

The kth derivative of F is always shown as D(F) when --hops is used. This should instead be a nested application of diff, k levels deep.