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维特比算法中的这一行具体做什么？

[英]What does this line in the Viterbi algorithm specifically do?

原文 2016-08-11 19:33:30 7 1 algorithm/ dynamic-programming/ notation/ viterbi

维特比线

I am more concerned in understanding the assignment arrow to the left followed by max s'=1 to N. Disregard the semantics of the variables. 我更关心理解左边的赋值箭头，后跟max s'= 1到N。忽略变量的语义。

Thank you! 谢谢！

1 个解决方案

It is a recursive formula to determine the value of viterbi[s,t] for a given value of s and t . 对于给定的s和t值，它是确定viterbi [s，t]的值的递归公式。

In fact, viterbi is a matrix of N rows, and s is a row number in that matrix, and t a column number. 实际上， 维特比是N行的矩阵，而s是该矩阵中的行号，而t是列号。

The value in the cell at s,t of the matrix is determined by taking all values in the previous column (column t-1 , and row s' going from 1 to N ), -- which are supposed to be already known -- and multiplying them by specific values from two other matrices (I ignore their role in this, but these matrices are a given, and the value of s , s' and t determine which value to pick from those matrices). 单元格中矩阵s，t处的值是通过取前一列中的所有值（列t-1 ，行s'从1到N ）确定的，这些值应该是已知的。并将它们乘以其他两个矩阵的特定值（我忽略了它们在其中的作用，但是这些矩阵是给定的，而s ， s'和t的值决定了从这些矩阵中选择哪个值）。

From all these N products, the greatest is taken. 从所有这N种产品中，获取最大的价值。

When you start with known values for the first column ( t = 1), you can find with this formula the values in the second column, and when you have those, the third, ...etc. 当您从第一列的已知值开始（ t = 1）时，可以使用此公式在第二列中找到值，而拥有这些值时，则可以找到第三列中的...等。