The wave packets both linear and nonlinear such as solitons (signals) described by a complex time-dependent function are mapped onto positive probability distributions (tomograms). Quasidistributions, wavelets and tomograms are shown to have an intrinsic connection. Analysis is extended to signals obeying to the von Neumann-like equation. For solitons (nonlinear signals) obeying to the nonlinear Schrödinger equation, the tomographic probability representation is introduced. It is shown that in the probability representation the soliton satisfies to a nonlinear generalization of the Fokker-Planck equation. Solutions to the Gross-Pitaevskii equation corresponding to solitons in Bose-Einstein condensate are considered.