请教：SAS矩阵赋值错误-经管之家官网！

请教各位朋友，下面是我编的一段程序，最后那个错误提示是为什么呢？不胜感激
line=82，col=13？
63 %let c11=2462499; %let c12=-15237;%let c13=391262; %let c14=4649443;%let c15=1540806; %let c16=-7024.20;
64 %let c21=-15237;%let c22=542725;%let c23=217862; %let c24=-145310;%let c25=-95813;%let c26=-11480;
65 %let c31=391261;%let c32=217862;%let c33=626039; %let c34=-1686817; %let c35=-460936; %let c36=-2840.09;
66 %let c41=4649443; %let c42=-145310; %let c43=-1686817; %let c44=50499756; %let c45=1382734; %let c46=26538;
67 %let c51=1540806; %let c52=-95813;%let c53=-460936;%let c54=1382734;%let c55=4235180; %let c56=3903.75;
68 %let c61=-7024.20;%let c62=-11480; %let c63=-2840.09; %let c64=26538; %let c65=3903.75; %let c66=584.12;
69
70
71 proc iml;
NOTE: IML Ready
72 reset print;
73 use rescaled_u;
74 read all var{c_u0 c_u1 c_u2 c_u3 c_u4 c_u5} into c_u;
75 s=((c_u`) * c_u)/298;
76 ls=(root(s))`;
77 sigma={&c11 &c12 &c13 &c14 &c15 &c16,
78 &c21 &c22 &c23 &c24 &c25 &c26,
79 &c31 &c32 &c33 &c34 &c35 &c36,
80 &c41 &c42 &c43 &c44 &c45 &c46,
81 &c51 &c52 &c53 &c54 &c55 &c56,
82 &c61 &c62 &c63 &c64 &c65 &c66};
ERROR: Mixing character with numeric in matrix literal at line=82 col=13.