How can I set an absolute fixed cell reference in Math formula? I want to use in each formula over the table the first row in every column, respectively. It would be equivalent to using $ in Excel. How can I implement that in Math formula?
The way KNIME works is fundamentally different than the way spreadsheets work. For example, you can't reference a cell like you would in Excel. There are good reasons for this (which I won't get into here).
One strategy you could take is to convert the top row of values in your table to variables and use the variables in your Math expression. To do this use a "Table Row To Variable" node. This node will provide you with a variable output port (red circle). Drag from the red port to the upper left corner of the Math Formula node; this will make the variables available to the Math Formula node** (they will be in the Flow Variable List in the Math Formula configuration form). I attached a simple example workflow (you can import it using the File -> Import KNIME Workflow menu.)
** Note: The red variable ports at the upper left and upper right of nodes are always there; they're just normally hidden. If you want to unhide them before connecting to them, right click the node and select "Show Flow Variable Ports".
Thanks for your hint. I do not see a chance to generate a new table out of or modulate the existing one, if I want to calculate all rows as percentages of the first row, with knime in-built node Math Formula or other nodes?
That is a pity. Then I have to code a R snippet.
I think dnaki's idea is a perfect solution for your problem. If you have got a really huge number of columns you can make your life easier by using a loop to iterate through all columns.
I have written a R snippet with the corresponding loop, which I have realized relatively fast. Thank you very much.