void setFilter (std::string filter_string)
set Filter string.
The string uses a , b , c , d to refer to first to the fourth column, and supports comparison and logical operator like C++. Parentheses can be used to group logic, but notice that the underlying hardware module does not support comparing one column with multiple constant boundaries in OR relationship. Integral constants will be extracted from expression.
For example, an expression could be (a < 10 && b < 20) || (c >= d) .
Parameters:
| filter_string | filter expression string |