The problem of dimension reduction is of increasing importance in modern data analysis. In this paper, we consider modeling the collection of points in a high dimensional space as a union of low dimensional subspaces. In particular we propose a highly scalable sampling based algorithm that clusters the entire data via first spectral clustering of a small random sample followed by classifying or labeling the remaining out of sample points. The key idea is that this random subset borrows information across the entire data set and that the problem of clustering points can be replaced with the more efficient and robust problem of "clustering sub-clusters". We provide theoretical guarantees for our procedure. The numerical results indicate we outperform other state-of-the-art subspace clustering algorithms with respect to accuracy and speed.

On a fine early afternoon in late March a young German-Iranian friend and I walked into the Garage Gallery at the Fire Station in Doha, Qatar - and we wondered. We were there to see the famous Chinese artist Ai Weiwei's "Laundromat": "A traveling installation", as the official description of the exhibition says, "that brings the current European migrant crisis into sharp focus." We had read before that "the work is centered around a vast makeshift camp near the village of Idomeni, on the border with the Republic of Macedonia. As part of his recently released documentary Human Flow, Ai Weiwei has borne witness to the brutal plight of refugees worldwide." Does the brutal plight of refugees worldwide - those from Syria in particular - need a witness?

A multiple-exposure portrait of Chinese contemporary artist and human rights activist Ai Weiwei, made on film in Beverly Hills, on the occasion of his new documentary, "Human Flow." A multiple-exposure portrait of Chinese contemporary artist and human rights activist Ai Weiwei, made on film in Beverly Hills, on the occasion of his new documentary, "Human Flow." (Jay L. Clendenin / Los Angeles Times) Ai Weiwei is nothing if not prolific. He spent the better part of 2016 traveling around the globe visiting refugee camps for his new documentary feature film, "Human Flow," debuting in theaters this month. He's made so much art that he currently has work in 12 museum and gallery exhibitions around the world -- eight of them solo shows. In New York, the contemporary artist and social justice activist is installing some 300 works across the city's five boroughs for the Public Art Fund exhibition "Good Fences Make Good Neighbors," opening Oct. 12.