4.3993e+04
>> y18=polyval(a,4146.4122)
y18 =
4.3989e+04
>> y19=polyval(a,4253.7634)
y19 =
4.4006e+04
>> y20=polyval(a,4339.39)
y20 =
4.4067e+04
>> y21=polyval(a,4411.5603)
y21 =
4.4156e+04
>> y22=polyval(a,4636.58)
y22 =
4.4690e+04
>> y23=polyval(a,4766.2183)
y23 =
4.5202e+04
>> y24=polyval(a,4927.6928)
y24 =
4.6087e+04
>> y25=polyval(a,5107.83205)
y25 =
4.7437e+04
>> 粮食产量和年份拟合 >
x0=[1983,1984,1985,1986,1987,1988,1989,1990,1991,1992,1993,1994,1995,1996,1997,1998,1999,2000,2001,2001,2003,2004,2005,2006,2007]; >>
y0=[38728,40731,37911,39151,40208,39408,40755,44624,43529,44264,45649,44510,46662,50454,49417,51230,50839,46218,45264,45706,4307,46947,48402,49804,50160]; >> a=polyfit(x0,y0,3) a =
1.0e+10 *
0.0000 -0.0000 0.0048 -3.2269
>> y10=polyval(a,2010)
y10 =
4.8499e+04
>> y11=polyval(a,2011)
y11 =
5.0179e+04
>> y12=polyval(a,2012)
y12 =
5.2179e+04
>> y13=polyval(a,2013)
y13 =
5.4523e+04
>> y14=polyval(a,2014)
y14 =
5.7235e+04
>> y15=polyval(a,2015)
y15 =
6.0340e+04
>> y16=polyval(a,2016)
y16 =
6.3862e+04
>> y17=polyval(a,2017)
y17 =
6.7825e+04
>> y18=polyval(a,2018)
y18 =
7.2254e+04
>> y19=polyval(a,2019) y19 =
7.7173e+04
>> y20=polyval(a,2020)
y20 =
8.2605e+04
>> y21=polyval(a,2021)
y21 =
8.8576e+04
>> y22=polyval(a,2022)
y22 =
9.5110e+04
>> y23=polyval(a,2023)
y23 =
1.0223e+05
>> y24=polyval(a,2024)
y24 =
1.0996e+05
>> y25=polyval(a,2025)
y25 =
1.1833e+05
>> y26=polyval(a,2026)
y26 =
1.2736e+05
>> y27=polyval(a,2027)
y27 =
1.3707e+05
>>y28=polyval(a,2028)
y28 =
1.4749e+05
>>y29=polyval(a,2029)
y29 =
1.5864e+05
>> y30=polyval(a,2030)
y30 =
1.7055e+05
粮食产量与粮食播种面积的拟合 >>
y0=[38728,40731,37911,39151,40208,39408,40755,44624,43529,44264,45649,44510,46662,50454,49417,51230,50839,46218,45264,45706,4307,46947,48402,49804,50160]; >>
x0=[114047,112884,108845,110933,111268,110123,112205,113466,112314,110560,110509,109544,110060,112548,112912,113787,113161,108463,106080,103891,99410,101606,104278,104958,105638]; >> a=polyfit(x0,y0,3) a =
1.0e+07 *
0.0000 -0.0000 0.0003 -9.9915
>> y1=polyval(a,114047) y1 =
4.9355e+04
>> y2=polyval(a,112884) y2 =
4.4241e+04
>> y3=polyval(a,108845) y3 =
4.4705e+04
>> y4=polyval(a,110933)