I have an rdd in pyspark which looks like follows: It has two sub matrices..(array,array) [ array([[-13.00771575, 0.2740844 , 0.9752694 , 0.67465999, -1.45741537, 0.546775 , 0.7900841 , -0.59473707, -1.11752044, 0.61564356], [ -0. , 12.20115746, -0.49016935, -0.9236129 , -1.1693633 , -0.39135626, 1.10752864, 0.16920118, -1.098806 , 1.10045185], [ 0. , 0. , -11.26425992, 0.56309152, 0.44872832, 0.69722768, 0.84200281, 0.89537327, 0.10460865, -0.62938474], [ -0. , -0. , 0. , 13.1112119 , 0.39986223, -1.22218936, 0.72315955, 0.12208597, -0.6258082 , -0.91077504], [ 0. , -0. , 0. , 0. , -11.04483145, -1.71948244, -0.73239228, -0.19651712, -0.97931725, -0.43263423], [ 0. , 0. , 0. , -0. , 0. , -12.1996715 , -0.05580816, 0.20517336, 0.53584998, 1.3370874 ], [ 0. , -0. , -0. , 0. , 0. , 0. , 12.32603631, 0.47498103, -0.65901705, -0.85713277], [ 0. , 0. , 0. , -0. , 0. , -0. , 0. , 11.90030251, 1.73036795, 0.70588443], [ -0. , -0. , 0. , 0. , -0. , -0. , 0. , -0. , 13.00493769, 1.37753403], [ 0. , -0. , 0. , 0. , 0. , -0. , 0. , 0. , -0. , -10.89006283]]),
array([[-12.43375184, 1.07703619, -0.47818221, 1.65919732, 0.96307502, -1.6322447 , -1.09409297, -0.64849112, -1.09349557, -0.68706834], [ 0. , -11.93616969, 0.08784614, 1.76677411, -0.0585134 , -0.70979485, 0.29757848, 1.19562173, -1.54176475, 1.71500862], [ 0. , -0. , -12.42060272, 2.17060365, -1.3212244 , 0.73742297, 0.50410937, -0.35278129, -0.40513689, -0.81222302], [ -0. , 0. , 0. , -11.93419851, -1.15614929, 1.04085489, 0.69986351, -1.3615322 , 0.43467842, -1.33041858], [ -0. , -0. , 0. , 0. , 11.22907137, -0.12925322, 0.46293906, -2.01577912, -2.26566926, -0.17750339], [ 0. , 0. , 0. , 0. , -0. , -12.0705513 , -0.19432359, 0.41226088, 0.79436699, -0.61288711], [ 0. , -0. , 0. , 0. , -0. , -0. , 11.99770753, -1.24277228, 1.32240282, 1.5140609 ], [ -0. , 0. , -0. , -0. , 0. , -0. , 0. , -13.07008472, 0.52031563, -1.56247391], [ 0. , -0. , 0. , 0. , -0. , -0. , -0. , -0. , 13.16585107, 0.57741265], [ 0. , 0. , -0. , -0. , 0. , 0. , 0. , -0. , -0. , -13.53719704]]) ] So, basically I have sub matrices like [sub_matrix_1, sub_matrix_2.... ] (the above has just two matrices.. I want to combine in one big matrix column wise [ sub_matrix_1 sub_matrix_2 .... ] Any suggestions?