matlab拟合那个是常数项啊?

matlab拟合那个是常数项啊?
A=[1 21.2
2 14.5
3 17.7
4 4.9
5 5.3
6 5.7
7 7.1
8 6.5
9 2.1
10 1.4]
x=A(:,1)
y=A(:,2)
[p,brint,r,rint,starts]=regress(y,x)
A =
1.0000 21.2000
2.0000 14.5000
3.0000 17.7000
4.0000 4.9000
5.0000 5.3000
6.0000 5.7000
7.0000 7.1000
8.0000 6.5000
9.0000 2.1000
10.0000 1.4000
x =
1
2
3
4
5
6
7
8
9
10
y =
21.2000
14.5000
17.7000
4.9000
5.3000
5.7000
7.1000
6.5000
2.1000
1.4000
Warning:R-square is not well defined unless X has a column of ones.
Type "help regress" for more information.
> In D:\数学建模\matlab\toolbox\stats\regress.m at line 105
p =
0.8265
brint =
-0.3223 1.9753
r =
20.3735
12.8470
15.2205
1.5940
1.1675
0.7410
1.3145
-0.1119
-5.3384
-6.8649
rint =
2.9202 37.8268
-8.6030 34.2970
-5.0295 35.4706
-21.7776 24.9657
-21.9328 24.2679
-22.0145 23.4966
-20.9960 23.6250
-21.9428 21.7189
-26.1501 15.4732
-26.6891 12.9592
starts =
0.5462 NaN NaN
>>