Demonstrating the EasyEDA Memristor using the ngspice Memristor XSPICE element. The memristor is a two-terminal resistor with memory, whose resistance depends on the time integral of the voltage across its terminals. rmin and rmax provide the lower and upper limits of the resistance, rinit is its starting value (no voltage applied so far). The voltage has to be above a threshold vt to become effective in changing the resistance. alpha and beta are two model parameters. The memristor code model is derived from a SPICE subcircuit published in: Y. V. Pershin, M. Di Ventra: "SPICE model of memristive devices with threshold", arXiv:1204.2600v1 [physics.comp-ph] 12 Apr 2012, http://arxiv.org/pdf/1204.2600.pdf See also: Dalibor Biolek, Member, IEEE, Massimiliano Di Ventra and Yuriy V. Pershin, Senior Member, IEEE: "Reliable SPICE Simulations of Memristors,Memcapacitors and Meminductors" arXiv:1307.2717v1 [physics.comp-ph] 10 Jul 2013 http://arxiv.org/pdf/1307.2717v1.pdf For more information about the the ngspice Memristor XSPICE model, please see: http://ngspice.sourceforge.net/docs/ngspice-manual.pdf#subsection.12.2.26 For information about Memristors, please see: http://en.wikipedia.org/wiki/Memristor