What does this error tell us when I'm trying to run an example in Apache Mahout?

I am studying to use Apache Mahout, and get the following message after running one of its example:

Exception in thread "main" org.apache.hadoop.mapreduce.lib.input.InvalidInputException: Input path does not ex开发者_StackOverflow中文版ist: file:/home/user1/workspace/LDAAnalysis/output/data

In fact, the directory of */output/data was found to be created there after running. I don't understand what does this error message tell us?

The first big question is, "what example"? Some are going to work locally, some won't. I assume it's LDA-related, but would be very helpful to say. Or print more of the stack trace.

It is not merely a question of writing the path correctly. You have to have the right destination set up. From your comment I am not sure if you have Hadoop set up or not or whether HDFS if running or where you've put your input.