Calculation of Parameters of Crop Water Production Function of Jensen model based on Simplex Particle Swarm Optimization Algorithm

In this paper, simplex particle swarm optimization algorithm (SMPSO) is introduced to calculate Parameters of Crop Water Production Function directly. The powerful global search ability of particle swarm optimization algorithm (PSO) and the well local search ability of simplex method (SM) are combined in SMPSO. The dimension of space of a particulate is determined by the phases of crop growth and development period in SMPSO, and the sensitive index lambda_i , an important parameter of crop water production function, is regarded as optimized variable to be calculated directly. This method can eliminate some problems existing in linear regression method, such as biased estimate and distortion of result and it can search the global optimization value more easily than the PSO. Through example analysis, we can see that the SMPSO is better than PSO in accuracy and calculation speed.