Power spectrum emulations at redshifts z = 0 (top left), z = 0.5 (top right), z = 1 (bottom left), and z = 10 (bottom right) for model regressions with a single parameter, Ω_m = 0.31. The top panel of each plot shows the power spectra obtained with our different emulation variants, extremely randomized trees (ET), neural networks (NN), Random Forests (RF), and support vector machines (SVM). The bottom panel in each plot shows the ratio of the power in each emulation to the power in the ground truth N-body simulation (P_E(k) = Estimated; P_S(k) = Simulated).