1. An information processing device comprising hardware including a microprocessor, the microprocessor comprising: an input unit for inputting a feature quantity vector and an objective variable corresponding to the feature quantity vector; a basis function generation unit for generating a basis function by randomly selecting a prototype function among a plurality of pre-stored prototype functions and randomly setting parameters of the selected prototype function for outputting a scalar quantity by mapping the feature quantity vector; a scalar quantity calculation unit for mapping the feature quantity vector using the basis function generated by the basis function generation unit and calculating the scalar quantity corresponding to the feature quantity vector; a basis function evaluation unit for evaluating whether or not the basis function used to calculate the scalar quantity is useful for estimating the objective variable using the objective variable input by the input unit along with the scalar quantity calculated by the scalar quantity calculation unit and the feature quantity vector corresponding to the scalar quantity; a generation alternation unit for generating a next-generation basis function by executing at least one operation from the selection of the useful basis function, generation of a new basis function by mutation and crossover using the useful basis function, and random generation of the new basis function on the basis of an evaluation result by the basis function evaluation unit, by utilizing an evolutionary technique, wherein generating further comprises randomly selecting a method of generating second-generation basis functions from among a mutation method, a crossover method, and a random generation method; an estimation function generation unit for generating an estimation function for estimating the objective variable from the scalar quantity by machine learning on the basis of the scalar quantity calculated by the scalar quantity calculation unit and the objective variable corresponding to the scalar quantity using the basis function evaluated to be useful by the basis function evaluation unit; and an output unit for outputting the estimation function generated by the estimation function generation unit, wherein processing of generating the estimation function by the estimation function generation unit, processing of generating the next-generation basis function by the generation alternation unit, processing of calculating the scalar quantity by the scalar quantity calculation unit, and processing of evaluating the basis function by the basis function evaluation unit are iteratively executed.