  We propose a simple method of constructing a system of differential equations
of chaotic behavior based on the regression only from a scalar observable
time-series data. The estimated system enables us to reconstruct invariant sets
and statistical properties as well as to infer short time-series. Our
successful modeling relies on the introduction of a set of Gaussian radial
basis functions to capture local structure. The proposed method is used to
construct a system of ordinary differential equations whose orbit reconstructs
a time-series of a variable of the well-known Lorenz system as a simple but
typical example. A system for a macroscopic fluid variable is also constructed.
