Estimate per-cell-type average expression profiles
Source:R/RaCInG_input_generation.R
dot-estimate_expression_profiles.RdFor each gene, solves a non-negative least squares regression of bulk TPM
expression across samples against per-sample cell-type fractions, giving
one expression value per gene per cell type:
bulk_expr[gene, sample] ~= sum_celltype fractions[sample, celltype] * profile[gene, celltype].