Fig. 1.

A heterogeneous network consists of drug similarity network ${\mathbf{S}}_r\in {ℝ}^{n_r\times n_r}$ with n_r drugs, disease similarity network ${\mathbf{S}}_d\in {ℝ}^{n_d\times n_d}$ with n_d diseases, drug-disease association network ${\mathbf{W}}_{\mathit{\text{rd}}}\in {ℝ}^{n_r\times n_d}$ between n_r drugs and n_d diseases. Each circle represents a drug, each hexagon represents a disease. In the drug (disease) similarity network, the solid edges describe the similarities of drug (disease) pairs. In the drug-disease association network, the solid edges indicate the known drug-disease associations, and the dashed edges indicate the potential associations between drugs and diseases, which are the new indications of drugs