Transform Block into Matrix Format

KNIME Analytics Platform
1

I need to convert a txt file with block-wise entry list into matrix format. Say I have following

# entry

index 1: A

index 2: 1

# EOF entry

# entry

index 1: B

index 2: 2

# EOF entry

 

I want to convert that to

index 1: A B

index 2: 1 2

(entry, EOF entry can be filtered out later on)

I have read-in the index names into column 1 and all values (A,B,1,2) into column 2 already. But now, how to proceed? Thank you

2

Hello rockbar,

You can use a GroupBy on the index and aggregate the value as list, and then use a Split Collection Column to get the desired format.

Best,
Ferry

3

With the pivoting node, this is also nicely done.

Best, Iris

4

I have problems configuring the pivot node.

When I use pivot on the index column and aggregation on column with the values. I get exactly one neverending row, entries not really identifiable anymore. Thus, something wrong here.

The GroupBy Node tells me, that the number of entries is too long ("Group contains too many values). I have to add, that the number of "entry" blocks is higher than 10,000! Thus, this high number might be a problem?

5

Ok, I realized, that the problem dimensions are too big. Therefore I reduced the dataset to have only one unique identifier index per entry and then did the compare too another dataset which was intended :-)