Question

matlab数据拟合老出错是怎么回事？

clc;clear
data=load('市镇乡.txt');
x1=data(:,1)'/10000;
x2=data(:,2)'/10000;
x3=data(:,3)'/10000;%数据没问题啊，我检验过
r=0:90;
fun=inline('a(1)*exp( -((a(2)-r)/a(3))^2 )','a','r');
a=nlinfit(r,x1,fun,[32, 30.09, 38.69]);
X1=a(1)*exp( -( (a(2)-r)/a(3) )^2 );
plot(t,x1,'o',t,X1);
284746.88 202044.15 840255.24
210324.4 159711.09 685471.38
249153.52 178953.39 759177.98
262096.56 196271.46 810772.6
291218.4 209741.07 847625.9
268568.08 213589.53 854996.56
310632.96 234756.06 943444.48
313868.72 228983.37 965556.46
323576 234756.06 1031892.4
323576 255922.59 1112969.66
352697.84 259771.05 1149822.96
342990.56 279013.35 1245641.54
362405.12 273240.66 1341460.12
375348.16 294407.19 1437278.7
462713.68 380997.54 1820553.02
498307.04 363679.47 1695251.8
501542.8 357906.78 1496243.98
550079.2 377149.08 1496243.98
478892.48 300179.88 1230900.22
397998.48 209741.07 965556.46
375348.16 196271.46 943444.48
410941.52 190498.77 884479.2
511250.08 234756.06 1009780.42
462713.68 228983.37 928703.16
430356.08 238604.52 921332.5
488599.76 269392.2 950815.14
501542.8 280937.58 958185.8
465949.44 277089.12 869737.88
546843.44 330967.56 1017151.08
537136.16 323270.64 1017151.08
601851.36 359831.01 1208788.24
640680.48 369452.16 1179305.6
669802.32 400239.84 1282494.84
679509.6 407936.76 1341460.12
数据放不下91组，我随便来了些，关键是能出图形就好 大神求救啊~~~~~

Answer 1

感谢楼上，自己把它给弄出来了，嘿嘿

主要是忘了x是向量，要 点平方~
a(1)*exp( -((a(2)-r)/a(3))^2 改成
a(1)*exp( -((a(2)-r)/a(3))^.2
另外
plot(t,x1,'o',t,X1);改成
plot(r,x1,'o',r,X1);
ok

Answer 2

既然数据没错，我给楼主个建议，把X1换个数表示，用Y1试试。。感觉是和x1重复了