如题，保留matrix和table原本的列名等，怎么没有index损失互相转换呢？
大概可以这样互相转换：
a = table(2020.01.01..2020.01.05 as date1, 1..5 as price, 6..10 as vol)
b = matrix(a[,1:]).rename!(a.date1,a.colNames()[1:])
c = table(b.rowNames() as date1,b)
