A technique for sieving the overdeterminedsystem is gived by utilizing least-square method and the unique solution with minimum-error is obtained.
采用最小二乘法求解矛盾方程组，可获得误差最小的唯一解。
2
LSQR and ART algorithms are applied separately to calculate tomography for the determined system of equation, overdeterminedsystem of equation and underdetermined system of equation.
Only in under very special circumstance, an overdetermined systems have accurate solutions and general an approximated solution is often found in some determination of the overdeterminedsystem.