An integral can also be considered a summation; in fact most integration is performed by computers by adding up values of the function between the integral limits A vector is a quantity having both a magnitude and a direction. The magnetization from nuclear spins is represented as a vector emanating from the origin of the coordinate system. Here it is along the +z axis In this picture an the vector is in the XY plane between the +X and +Y axes. The vector has X and Y components and a magnitude equal to (X2+Y2)12 Matrices A matrix is a set of numbers arranged in a rectangular array. This matrix has 3 rows and 4 columns and is said to be a 3 by 4 matrixAn integral can also be considered a summation; in fact most integration is performed by computers by adding up values of the function between the integral limits. Vectors A vector is a quantity having both a magnitude and a direction. The magnetization from nuclear spins is represented as a vector emanating from the origin of the coordinate system. Here it is along the +Z axis. In this picture the vector is in the XY plane between the +X and +Y axes. The vector has X and Y components and a magnitude equal to ( X2 + Y2 )1/2 Matrices A matrix is a set of numbers arranged in a rectangular array. This matrix has 3 rows and 4 columns and is said to be a 3 by 4 matrix