This program combines list-driven photometry files from the CASU pipeline toolkit or CASUTOOLS into light curves, optionally performing differential photometry. Output is written to FITS binary tables.

Most of the documentation is in the form of a man page. To view this without installing it:

nroff -man -Tascii lightcurves.man | more

GNU "less" produces slightly nicer formatting, if available.

• A C99 compiler on a POSIX / UNIX-like platform.

The use of the mmap system call can be disabled if needed, but there are other dependencies and assumptions specific to this type of system, such as the use of getopt and isatty, which are POSIX functions. I may be motivated to fix this if it is a serious problem.

The program has been successfully compiled and run on Windows using MinGW. Native Windows API calls are used in buffer.c to perform memory mapping if HAVE_MMAP is defined (this is the default in the Makefile). Full functionality has not been tested thoroughly so some issues may remain.

• My C subroutine library from "lib" on github.

The Makefiles currently assume it's located in a directory "../lib". Please refer to the README.md file there for notes on how to install the IERS data files and JPL ephemerides. These are needed to compute Barycentric Julian Dates (BJDs) in the output file. The program will run without them, but the BJD values will not be written.

• CFITSIO, version 3.x http://heasarc.gsfc.nasa.gov/fitsio/

The Makefile uses pkg-config to obtain suitable compiler and linker flags for CFITSIO. On some systems, if CFITSIO is installed in a non-standard location, the PKG_CONFIG_PATH environment variable may need to be adjusted to allow pkg-config to find the cfitsio.pc file installed by CFITSIO.

• PGPLOT >= 5.1.1 (optional, plots disabled if unavailable) http://www.astro.caltech.edu/~tjp/pgplot/

To disable use of PGPLOT, comment out the appropriate lines in the Makefile. This will result in no diagnostic plots being produced, but this is not a serious problem, most of the quantities needed to produce them appear in the output files. The most important of these is an RMS versus magnitude diagram, and can be produced by plotting the "rms" versus "medflux" columns from the output file using your favourite method for plotting columns of FITS binary tables.

The Fortran compiler (FC variable in "make") is used to link the binaries in order to bring in any runtime dependencies for PGPLOT. This can be changed to use the C compiler if PGPLOT is not being linked. Please refer to the appropriate commented section of the Makefile.

CASUTOOLS (publicly available) or the CASU pipeline toolkit (not publicly available) are needed to produce suitable input files, but these packages are not directly needed to compile, link, or run anything in this package.

For CASUTOOLS, see: http://casu.ast.cam.ac.uk/surveys-projects/software-release

Type "make" to build both binaries. There is no install target, but this can be done if desired by copying the binaries "lightcurves" and "update" to a suitable location, and "lightcurves.man" can be placed in one of the man1 directories on the man path so the standard "man" utility can find it. If installing these binaries on the system, it would be advisable to rename "update" to a more descriptive name, less likely to clash with other packages, such as "lightcurves-update".

The standard Makefile should work unmodified if:

(a) pkg-config can find cfitsio.pc (see above). (b) the PGPLOT_DIR environment variable points to your PGPLOT installation, or PGPLOT is installed in one of the system include and library paths. (c) the FC variable in "make" points to the correct Fortran compiler.

Invariably, one of these things is not true for most real systems, especially in astronomy departments.

Item (c) deserves a special note. Most "make" programs I have come across recently default to FC=f77, which is almost always the wrong choice on modern systems (in fact, it often does not even exist!). On most Linux and other systems using the GNU compiler collection, you will need to set FC=gfortran. This can be done on the "make" command line or with an environment variable.