我的程序几经大家的帮助，终于运行了！但是我算的物理量怎么是字母呢？

第一列是时间点，第二列是空间点，第三列本应是我算的量的数值，怎么都变字母NAN了呢，第四列是另一个物理量，输出的没有问题！
请大家帮我分析分析！谢谢
第          60个时段
          60           1 NaN                       8140.77150876032     
          60           2 NaN                       18885.4070493370     
          60           3 NaN                       19674.0875379360     
          60           4 NaN                       19032.9832450080     
          60           5 NaN                       14642.2308576000     
          60           6 NaN                       9646.34127330240     
          60           7 NaN                       5176.08929352262     
          60           8 NaN                       2373.87853970987     
          60           9 NaN                       1012.30290810387     
          60          10 NaN                       344.302188666955     
          60          11 NaN                       81.5230139496832     
          60          12 NaN                       21.4012916138806     
          60          13 NaN                       3.31774766177148     
          60          14 NaN                      0.478183969448661     
          60          15 NaN                      6.619621383798700E-002
          60          16 NaN                      3.532762042269388E-002
          60          17 NaN                      0.000000000000000E+000
          60          18 NaN                      0.000000000000000E+000
          60          19 NaN                      6.458604725626357E-004
          60          20 NaN                      0.000000000000000E+000
          60          21 NaN                      0.000000000000000E+000
          60          22 NaN                      0.000000000000000E+000
          60          23 NaN                      0.000000000000000E+000
          60          24 NaN                      0.000000000000000E+000
          60          25 NaN                      0.000000000000000E+000
          60          26 NaN                      0.000000000000000E+000
          60          27 NaN                      0.000000000000000E+000