Dataset 'cpus' from the R MASS package. According to the description in the documentation of the package (https://cran.r-project.org/web/packages/MASS/MASS.pdf ): "A relative performance measure and characteristics of 209 CPUs. Source: P. Ein-Dor and J. Feldmesser (1987) 'Attributes of the performance of central processing units: a relative performance prediction model.' Comm. ACM. 30, 308–317" We converted the data to a text file by the following R commands: library('MASS') write.matrix(cpus,file='/tmp/cpus.txt',sep=',') X = logarithm of the second column ('syct', cycle time in nanoseconds) Y = logarithm of the seventh column ('perf', published performance on a benchmark mix relative to an IBM 370/158-3) We consider syct to be one of the causes of perf. Ground truth: X -> Y