Data analysis defines the following three methods.
|Classes unknown and
found from many data and formed into classes.
|Classes have already
been defined and
you only decide to which class a new object
|Identification of a trend line in the data sets and formation of relationships between data X and Y.|
With 2D data X and Y this is almost obvious with the classes and trend lines, but face multidimensional data sets and try to find classes and trend lines or dependencies there! Only methods (neural networks) and tools (software tools) can help.