“…Problem (1.1) with P[x) = \\x\\i and Problem (1.2) arise in many applications, including compressed sensing [9,13,24], signal/image restoration [5,19,23], data mining/classification [3,14,21], and parameter estimation [8,20]. There has been considerable discussion on the problem (1.1), see for instance [2,6,7,11,15]. If P is also smooth, then a coordinate gradient descent based on Armijo-type rule was well developed for the unconditional minimization problem (1.1) in Karmanov [10, pp.…”