FORC+ : First Order Reversal Curves + Reversibility

Display produced by FORC+
FORC+ is a program that will read a FORC data file generated by an AGM or VSM and display the FORC curves and the irreversible (Preisach density) and reversible FORC distributions. It can also construct the same plots for simple models, for comparison with experimental data.

The advantage of FORC+ over other programs for displaying the FORC density is that it avoids or decreases the need for averaging, by displaying positive and negative density in complementary colors, so that noise looks white from a distance and real positive and negative features stand out. It also is a stand-alone program -- it will run on a Windows PC without any third-party graphics software. Installation is trivial (copy two files) and then you just drag your data file to the executable. It is free to use, but we ask that if you publish something using it you cite this website ( and a paper describing the method: AIP Advances 9, 035117 (2019) (you may need to open this in a new tab). A slightly expanded version of this paper can be downloaded from ArXiV .

Please note that the present version is very preliminary -- it does not have axis labels or numbers. A powerpoint presentation with screen snapshots to which axis labels have been added is here. The presentation also has a brief introduction to the FORC method, some references, and a description of the reversible switching field distribution that is added in FORC+.

There are some papers that use FORC+ listed here. The patterned Co/Pd multilayer whose FORC curves are shown at the right is described in: A. G. Owen, Hao Su, A. Montgomery and S. Gupta, J. Vac. Sci. Technol. B 35, 061801(2017).

To get started, download and run the latest (beta) version (1.84). Previous versions are listed on version history

This code has been developed by P. B. Visscher.