用matlab做多元线性回归，程序输入如下：
x1=[1996.25,1996.5,1996.75,1997,1997.25,1997.5,1997.75,1998,1998.25,1998.5,1998.75,1999,1999.25,1999.5,1999.75,2000,2000.25,2000.5,2000.75,2001,2001.25,2001.5,2001.75,2002,2002.25,2002.5,2002.75,2003,2003.25,2003.5,2003.75,2004,2004.25,2004.5,2004,75,2005,2005.25,2005.5,2005.75,2006,2006.25,2006.5,2006.75,2007,2007.25,2007.5,2007.75,2008,2008.25,2008.5,2008.75,2009,2009.25,2009.5,2009.75,2010,2010.25,2010.5,2010.75,2011,2011.25,2011.5,2011.75,2012]';
x2=[1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0]';
x3=[0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0]';x4=[0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0]';
y=[9.910631, 9.910631, 9.910631, 9.910631, 9.999405, 9.999405, 9.999405, 9.999405,10.07481,10.07481,10.07481,10.07481,10.14836,10.14836,10.14836,10.14836,10.22918,10.22918,10.22918,10.22918,10.30895,10.30895,10.30895,10.30895,10.39594,10.39594,10.39594,10.39594,10.49148,10.49148,10.49148,10.49148,10.58754,10.58754,10.58754,10.58754,10.6947,10.6947,10.6947,10.6947,10.81403,10.81403,10.81403,10.81403,10.94651,10.94651,10.94651,10.94651,11.03849,11.03849,11.03849,11.03849,11.12664,11.12664,11.12664,11.12664,11.22592,11.22592,11.22592,11.22592,11.32396,11.32396,11.32396,11.32396]';
e=ones(64,1);
[b,bint,r,rint,stats]=regress(y,[e,x1,x2,x3,x4],0.05)

运行老是提示：Error using horzcat
CAT arguments dimensions are not consistent.

什么问题，怎么解决？