Healthy tissues in the body are usually diploid, with one chromosome inherited from each parent. Carcinogenesis is often associated with changes of copy number of whole chromosomes or chromosomal segments. To improve our understanding of cancer evolution and customization of therapy to individual patients, identifying the haplotype of origin of these copy number changes is critical. In this project, we are developing tools for phasing of polyploid genomes and haplotype-specific copy number inference in single cells using computational and machine learning methods.