[en] A software for microcomputer of PC type has been developed to set an automatic treatment of the
stress-strain curves drawn from rock testing systems. The software implements procedures for smoothing
and detecting the characteristic points of stress-strain curves. The smoothing is made by three points
sliding mean, while the detection of the characteristic points is made by an original treatment using
numerical derivatives. This treatment allows the setting of the onset of the linear portion of the curve, the
elastic limit and the failure strength. The software implements also an original algorithm to build Mohr's
envelopes. It has been tested with satisfactory results on many rocks ranging from fragile to ductile
materials.
