A system, comprising: an array of n electrodes; an electrical line; a switching circuit via which the electrodes are individually coupleable to the electrical line; a sensor; and processing circuitry; wherein the system is configured for the following to be performed in each of m iterations: (i) coupling, by the switching circuit, a subset of electrodes to the electrical line; (ii) sensing, by the sensor, an electrical parameter produced over the electrical line by a subset of electrodes coupled to said electrical line; and (iii) obtaining, by the processing circuitry and from the sensor, a value of the electrical parameter; wherein m is less than n; wherein the processing circuitry is configured to identify those of the electrodes that exhibit outlier electrical behavior by calculating a 11 a 12 a 1 n a 21 a 22 a 2 n a m 1 a m 2 a mn x 1 x 2 x n = b 1 b 2 b m; each row of a 11 a 12.. a 1 n a 21 a 22.. a 2 n..... a m 1 a m 2.. a mn and of b 1 b 2. b m corresponds to one of the m iterations; each column of a 11 a 12 ⋅ ⋅ a 1 n a 21 a 22 ⋅ ⋅ a 2 n ⋅ ⋅ ⋅ ⋅ ⋅ a m 1 a m 2 ⋅ ⋅ a mn corresponds to one of the n electrodes in the array; each position of a 11 a 12 ⋅ ⋅ a 1 n a 21 a 22 ⋅ ⋅ a 2 n ⋅ ⋅ ⋅ ⋅ ⋅ a m 1 a m 2 ⋅ ⋅ a mn is populated with either a first value or a second value depending on whether the electrode was enabled or disabled in the iteration; each position of b 1 b 2 b m is populated with the value of the electrical parameter for the iteration; and each of the x values is an unknown, which the processing circuitry determines by finding the set of x values that satisfy a 11 a 12 a 1 n a 21 a 22 a 2 n a m 1 a m 2 a mn x 1 x 2 x n = b 1 b 2 b m; wherein the processing circuitry is configured to determine a plurality of sets of x values that are each plausible, calculate the sum of |x 1 |+|x 2 |+... |x n |, and select the set whose sum is smallest; and wherein the processing circuitry is configured to select outliers from the set whose sum is smallest and to identify the corresponding electrodes as outlier electrodes. an array of n electrodes; an electrical line; a switching circuit via which the electrodes are individually coupleable to the electrical line; a sensor; and processing circuitry; wherein the system is configured for the following to be performed in each of m iterations: (i) coupling, by the switching circuit, a subset of electrodes to the electrical line; (ii) sensing, by the sensor, an electrical parameter produced over the electrical line by a subset of electrodes coupled to said electrical line; and (iii) obtaining, by the processing circuitry and from the sensor, a value of the electrical parameter; (i) coupling, by the switching circuit, a subset of electrodes to the electrical line; (ii) sensing, by the sensor, an electrical parameter produced over the electrical line by a subset of electrodes coupled to said electrical line; and (iii) obtaining, by the processing circuitry and from the sensor, a value of the electrical parameter; wherein m is less than n; wherein the processing circuitry is configured to identify those of the electrodes that exhibit outlier electrical behavior by calculating a 11 a 12 a 1 n a 21 a 22 a 2 n a m 1 a m 2 a mn x 1 x 2 x n = b 1 b 2 b m; each row of a 11 a 12.. a 1 n a 21 a 22.. a 2 n..... a m 1 a m 2.. a mn and of b 1 b 2. b m corresponds to one of the m iterations; each column of a 11 a 12 ⋅ ⋅ a 1 n a 21 a 22 ⋅ ⋅ a 2 n ⋅ ⋅ ⋅ ⋅ ⋅ a m 1 a m 2 ⋅ ⋅ a mn corresponds to one of the n electrodes in the array; each position of a 11 a 12 ⋅ ⋅ a 1 n a 21 a 22 ⋅ ⋅ a 2 n ⋅ ⋅ ⋅ ⋅ ⋅ a m 1 a m 2 ⋅ ⋅ a mn is populated with either a first value or a second value depending on whether the electrode was enabled or disabled in the iteration; each position of b 1 b 2 b m is populated with the value of the electrical parameter for the iteration; and each of the x values is an unknown, which the processing circuitry determines by finding the set of x values that satisfy a 11 a 12 a 1 n a 21 a 22 a 2 n a m 1 a m 2 a mn x 1 x 2 x n = b 1 b 2 b m; wherein the processing circuitry is configured to determine a plurality of sets of x values that are each plausible, calculate the sum of |x 1 |+|x 2 |+... |x n |, and select the set whose sum is smallest; and wherein the processing circuitry is configured to select outliers from the set whose sum is smallest and to identify the corresponding electrodes as outlier electrodes.