Order-independent constraint-based causal structure learning for gaussian distribution models using GPUs

Abstract

Learning the causal structures in high-dimensional datasets allows deriving advanced insights from observational data, thus creating the potential for new applications. One crucial limitation of state-of-the-art methods for learning causal relationships, such as the PC algorithm, is their long execution time. While, in the worst case, the execution time is exponential to the dimension of a given dataset, it is polynomial if the underlying causal structures are sparse. To address the long execution time, parallelized extensions of the algorithm have been developed addressing the Central Processing Unit (CPU) as the primary execution device. While modern multicore CPUs expose a decent level of parallelism, coprocessors, such as Graphics Processing Units (GPUs), are specifically designed to process thousands of data points in parallel, providing superior parallel processing capabilities compared to CPUs. In our work, we leverage the parallel processing power of GPUs to address the drawback of the long execution time of the PC algorithm and develop an efficient GPU-accelerated implementation for Gaussian distribution models. Based on an experimental evaluation of various high-dimensional real-world gene expression datasets, we show that our GPU-accelerated implementation outperforms existing CPU-based versions, by factors up to 700.