R Snippet (R/Local/R Snippet) interprets strings as doubles? Example attached

[eduece99]

Dear KNIME,

 

I've a problem with the attached workflow where I suspect there's a bug in the workflow.  It's difficult to explain without one opening the workflow, but here's what I can summarise:

 

- input = a set of double datatype columns

- process = the row of each double column with the maximum value has the character "m" appended to it & output

- problem - R/Local/R Snippet interprets the output column as double datatype even though there's a string value - it should be output as a String datatype! 

Strangely (as attached) the Knime Labs "Table to R" then "R to Table" does this correctly.  Also, the R/Local/R Snippet interprets the column as a string when there are 2 (not 1) rows with characters in them.

 

Very specific bug (unless it's an intended feature?) but significant nevertheless IMO

Ed.

 

 

Ed.

• r_snippet_doublestring_bug.zip

[Aaron_Hart]

Hi Ed, 

If you notice the nodes in your examples have different Icons, then are actually from different extensions.  If you add a new R Snippet node, it will have the new icon, and you can then use something like:

BEDROCS.R <- apply(knime.in, 2, function(cols) {
  max.index <- which( max(cols) == cols )
  cols[ max.index ] <- paste( cols[ max.index ], "m", sep="" )

  as.character(cols)
} )

knime.out <- data.frame(BEDROCS.R)

[eduece99]

Aaron,

 

Yeah I know they're different extensions - I don't understand why they're behaving differently in this instance, hence why I'm reporting this.

 

Ed.

[Aaron_Hart]

Does the problem persist in the current integration? If so, I can investigate further.  

[eduece99]

Aaron,

 

I'm using KNIME 2.9.4.  I'm not using quite the latest version although I have a colleage who does - I can ask him.  I doubt there'll be a difference though.

 

Ed.