问题
Is there a way to automatically convert NA values to ? in weka while loading .csv files? Or do we have to use some other script/program to either replace them with ? or a blank space before loading into weka.
Any help or suggestions are welcome. Thanks
回答1:
Unfortunately I do not believe Weka has a way to do this conversion. This is the case because Weka's native format is .arff files. In .arff files, missing values are denoted with a "?". When a .csv file is loaded, it expects missing values to also be denoted by "?".
Depending on your method of using Weka I suggest:
For the Weka GUI, use "find and replace" in a simple text editor to change "NA" to "?" before loading the .csv into Weka.
For the Weka Java API, write a method to preprocess your ".csv" file before handing it over to the Weka .csv loader.
来源：https://stackoverflow.com/questions/19210756/convert-na-values-to-automatically-while-loading