Well, sounds like you are loading classes that need Hadoop, and you have not put Hadoop in your classpath.
These questions aren't particularly specific to Mahout -- I think you'd benefit from learning a bit more about how Java works first. It'll get you past a lot of small issues like this. On Fri, Sep 4, 2009 at 11:55 PM, Sven Boekhoff<[email protected]> wrote: > It does nor work. > It throws the error: > > Exception in thread "main" java.lang.NoClassDefFoundError: > org/apache/hadoop/io/Writable > at java.lang.ClassLoader.defineClass1(Native Method) > at java.lang.ClassLoader.defineClass(ClassLoader.java:621) > at > java.security.SecureClassLoader.defineClass(SecureClassLoader.java:124) > at java.net.URLClassLoader.defineClass(URLClassLoader.java:260) > at java.net.URLClassLoader.access$000(URLClassLoader.java:56) > at java.net.URLClassLoader$1.run(URLClassLoader.java:195) > at java.security.AccessController.doPrivileged(Native Method) > at java.net.URLClassLoader.findClass(URLClassLoader.java:188) > at java.lang.ClassLoader.loadClass(ClassLoader.java:307) > at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301) > at java.lang.ClassLoader.loadClass(ClassLoader.java:252) > at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320) > Caused by: java.lang.ClassNotFoundException: org.apache.hadoop.io.Writable > at java.net.URLClassLoader$1.run(URLClassLoader.java:200) > at java.security.AccessController.doPrivileged(Native Method) > at java.net.URLClassLoader.findClass(URLClassLoader.java:188) > at java.lang.ClassLoader.loadClass(ClassLoader.java:307) > at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301) > at java.lang.ClassLoader.loadClass(ClassLoader.java:252) > at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320) > ... 12 more > Could not find the main class: Main. Program will exit. > > Do I need the hadoop library? This is not written in the requirements,... > > > Sean Owen wrote: >> >> I think you probably want to study basic Java first then or you're >> going to run into a lot more confusion. >> >> Vector probabilities = new SparseVector(); >> >> is what you want. Interfaces and instantiating objects are the very >> basics of Java. >> >> On Fri, Sep 4, 2009 at 5:30 PM, Sven Boekhoff<[email protected]> wrote: >>> >>> I never worked with interfaces. >>> And i also don't know what "instantiate an implementation" means. >>> How does it look like? >>> >>> Sean Owen wrote: >>>> >>>> Yes, Vector is an interface! You need to instantiate an implementation >>>> like DenseVector. >>>> >>>> On Fri, Sep 4, 2009 at 5:25 PM, Sven Boekhoff<[email protected]> wrote: >>>>> >>>>> But i cant create an Vector object: >>>>> >>>>> Vector probabilities = new Vector(); >>>>> >>>>> gives an error. >>>>> >
