We demonstrated the identification of unresponsive and ranked responsive directions in non-injective, singleand double-MOF sensor arrays based on HKUST-1 and Co-MOF-74 immersed in a mixture involving CH 4 , CO 2 , C 2 H 6 , and N 2 relevant to natural gas sensing . Our case studies involved ≤two MOFs and ≤four components in the gas, instructively allowing us to visualize a(x) and clarify the meaning of the unresponsive and ranked responsive directions in gas composition space. The SVD in eqn. 6 is particularly powerful for large sensor arrays and high-dimensional gas composition spaces where, unfortunately, visualization of a(x) is extremely difficult.