用曲线拟合进行施肥效果分析.doc

本科学生毕业论文 用曲线拟合进行施肥效果分析 系部名称： 数学系 专业班级： 学生姓名： 指导教师： 曲绍平 袁海燕 职 称： 副教授 助教 黑 龙 江 工 程 学 院 二○○九年六月  The Graduation Thesis for Bachelors Degree The Effective Analysis Being in Progress with Curve Fitting Of Applying Fertilizer Candidate：Wang Zhihui Specialty：Information and complete science Class：B05-75 Supervisor：Association prof. Qu Shaoping Assistant of Yuan Haiyan Heilongjiang Institute of Technology 2009-06·Harbin 摘 要 本论文是在数学基本理论的指导下，利用从某研究所获得的某地区土豆和生菜生长所需的营养素氮（N），磷（P），钾(K)的施肥量及其相应产量的实验数据，应用数学软件MATLAB对所得的数据进行曲线拟合，并用曲线拟合的几种方法分别求得施肥量与产量之间的函数关系。最后，对所得的结果从应用方面进行评价，以及给出相应的改进方案。 首先，研究每一种肥料的施肥量对产量的影响，将另外两种肥料始终固定在第七种水平上，我们用最小二乘法和插值法求得土豆和生菜的产量与氮、磷、钾的施肥量之间的函数关系；其次，用多元回归法求得在三种肥料共同影响下施肥量与产量之间的函数关系。通过讨论我们分别求出了三种肥料有一个是变量（另外两个保持在第七种水平上）和都是变量两种情况下的最优解，当然，从实际应用方面来看，后者所得的结果更有指导意义。 关键词：生菜；土豆；施肥量；产量；经验公式；曲线拟合  ABSTRACT The thesis is guided by fundamental theory of mathematics, making use of experiment data which is some area potatoes and lettuce gaining from some research institutes to grow required nutrient nitrogen (N) , phosphorus (P), potassium (K) fertilization amounts and their corresponding output , and applied mathematics software MATLAB to carry out the curve fitting on the gains data and use several kind methods of curve fitting to ask for the function relation between the amounts of applying fertilizer and output respectively .Finally, we carry out valuation on the result from the aspect of applying and give out a corresponding improvement scheme. Firstly, we study the impact of the amounts of applying fertilizer about every species fertilizer over output, another two kinds fertilizer fixing in the seventh kinds level upper, we are asking for the function relation of the nitrogen , the phosphorus, the potassium fertilization amounts and the output about the potatoes and l