android,runtime-error,broadcasting

See this part in the error message: NumberFormatException: Invalid int: "null" you seem to try to parse the String "null" to an int. This is not possible and will therefore throw NumberFormatException....

matrix,octave,matrix-multiplication,broadcasting

This is because Octave (in a notable difference from Matlab) automatically broadcasts. The * operator in Octave is the matrix multiplication operator. So in your case a*b would output (in Matlab as well) a*b ans = 1 2 3 2 4 6 3 6 9 which should be expected. The...