clear all
close all
clc

x1 = [1	 2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20];
y0 = [16	32	70	142 	260 	436 	682	 1010	1432	1960	2606	3382	4300	5372	6610	8026	9632	11440	13462	15710];
%y0 = [16	32	70	142 	265 	436 	680	 1010	1432	1960	2606	3382	4300	5372	6610	8026	9000	11440	13432	15700];

figure
plot(x1,y0,'r*')

p1 = polyfit(x1,y0,1)   			%一階擬合  
y1 = polyval(p1,x1)
hold on
plot(x1,y1,'r-')

p2 = polyfit(x1,y0,2)   			%二階擬合  
y2 = polyval(p2,x1)
hold on
plot(x1,y2,'b-')

p3 = polyfit(x1,y0,3)   			%三階擬合  
y3 = polyval(p3,x1)
hold on
plot(x1,y3,'m-')

p4 = polyfit(x1,y0,4)   			%四階擬合  
y4 = polyval(p4,x1)
hold on
plot(x1,y4,'g-')
xlabel('溫度(攝氏度)')
ylabel('蒸發(fā)速度(ml/h)')
legend('data','一階擬和','二階擬和','三階擬和','四階擬和')