The data is organized as follows. The 32 electrodes are arranged in a circular array, so that the center of electrode n is at position theta_n = 2*pi*n/32.
The first number in each file is the magnitude M of the applied current. The next 32 numbers in the data file are the voltages on the 32 electrodes that arise from the current pattern cos(theta) (i.e., the current on the nth electrode is M*cos(theta_n)); the second 32 numbers are voltages that arise from the current pattern cos(2*theta); etc. Thus, after the magnitude M, the next 16*32 numbers are voltages due to the patterns cos(theta), cos(2*theta), ... cos(16*theta). After this are 32 numbers that arise from the current pattern sin(theta); the next 32 numbers are from sin(2*theta), etc. The last set of 32 numbers is from sin(15*theta).