Transforming multidimensional data into a onedimensional sequence using space-filling curves, such as the Hilbert curve, has been studied extensively in many papers. This work provides a systematic presentation of the construction of an arbitrarily accurate multidimensional space-filling curve approximation which is a generalization of the Sierpi ński spacefilling curve. At the same time, according to the space-filling curve construction, we present a simple algorithm for determining one of the counter-images on a unit interval of a data point lying in a multidimensional cube. The computational complexity of the algorithm depends linearly on the dimension of the cube. The paper contains numerical algorithms for local generation of the curve approximation and determination of the quasi-inverse of a data point used to transform multidimensional data into the one-dimensional form.