我正在读取外部文本文件（30 行，7 列）的数据帧，每一行都用“，”分隔。我的缺失值表示为“，”。当我将数据读入二维数组时，缺失值被替换为 0.00，但我在数据中也有 0.00 值。当我计算平均值时，计数（项目数（n））显示为计数 - （缺失值的数量）。如何动态选择缺失值。
谢谢斯里
数据
337.60,220.40,0.00,0.00,200.42,216.61,261.04
323.00,249.20,65.30,0.00,201.93,210.91,309.98
116.80,474.80,0.00,0.00,203.43,215.76,234.93
72.10,505.90,0.00,0.00,204.93,215.72,233.47
148.30,771.70,0.00,0.00,206.44,217.00,239.05
90.70,287.20,0.00,0.00,207.94,215.43,216.85
337.20,334.50,10.20,0.00,209.45,226.85,306.57
142.50,142.80,0.00,0.00,210.95,240.09,240.31
279.10,289.60,51.80,0.00,212.45,227.75,262.30
273.60,337.70,0.00,0.00,213.96,256.86,223.66
332.40,425.60,0.00,0.00,215.46,238.36,237.63
45.70,299.30,0.00,0.00,216.96,223.92,241.41
49.10,529.40,0.00,0.00,218.47,235.81,282.17
185.30,331.80,38.00,0.00,219.97,235.81,309.29
552.90,454.80,0.00,0.00,221.47,224.60,269.09
176.20,441.60,0.00,0.00,222.98,232.44,293.95
170.00,,0.00,,,,327.96
200.00,,0.00,,,,291.69
241.20,156.00,0.00,0.00,227.49,235.55,278.66
118.00,383.20,3.20,0.00,228.99,269.28,325.31
62.00,189.70,0.00,0.00,230.50,248.73,266.95
400.20,244.20,0.00,0.00,232.00,239.70,271.27
163.70,826.60,0.00,500.00,233.50,245.06,294.98
250.40,236.60,0.00,0.00,235.01,261.72,288.24
51.30,684.20,0.00,0.00,236.51,245.06,237.37
412.50,128.90,0.00,500.00,238.01,245.16,268.66
452.00,,,,,,314.68
481.00,155.50,0.00,0.00,241.02,278.72,348.44
162.20,201.90,0.00,500.00,242.52,250.36,255.58
171.80,152.00,0.00,500.00,244.03,246.85,339.06