Heatmap node does not display svg images anymore when hovering over row ID

A nice feature of the Heatmap node I’ve used in the past was that it could display svg images when hovering over the table’s row IDs in the interactive view. This feature can be enabled by opening the node configuration window, selecting an svg-formatted column in the “Choose an image column:” dialog of the Options tab and selecting the “Show tool tips” option in the view Configuration tab.

Unfortunately after an update of the KNIME Analytics Platform I realised that this option no longer works. As you can see in the attached screenshot, when I’m hovering over the rowID of the heatmap interactive view, a small empty frame appears instead of the selected svg images. I’m running the KNIME Analytics Platform on a Mac Ventura 13.3.1 (a).

I attached a minimal workflow to exemplify this.

Please, can anybody tell me if I’m doing something wrong or if this feature no longer works? Can you reproduce the problem on your machines?

Thanks in advance.


heatmap_svg_problem.knwf (16.8 KB)

hi @gcincilla
been able to reproduce the issue on my machine. the green bar length changes when hovering, as shown in the attachment. please let me know if this is what you were looking for. if not, i apologize.

knime 5.1
linux mint 21.2

1 Like

Hi @marzukim, thanks for your quick reply.
I expect to see a molecular structure instead of a green bar (you can see those by inspecting the input table). Anyway, I cannot see neither that green bar (on Mac and KNIME AP 4.7). Possibly the green bar is another problem.

1 Like

hoping an expert can verify those issues. possibly the green bar not image is another problem. sorry for not understanding the real issues here.



I think the green bars is also what you are seeing in the table view? So I guess this is just the image you have in the table. @gcincilla the problem seems to stem from the fact that the svg lost the width and height attribute. Therefore, the tooltip is 0x0px large which appears in this small tooltip box you are seeing. By using an “RDKit Molecule to SVG” node to recreate the SVGs it seems to work nicely again. It seems that this loss of the width and height attribute comes from some changes in the “Renderer to Image” node. Can you tell me in which version it is still working?



Hey @DanielBog, thank you very much for the workaround. Effectively, I can confirm that using the RDKit Molecule to SVG node solves the problem!

Currently I’m working on KNIME AP 4.7 but I’m not sure that the problem is due to the Render to Image node. I’m saying this because in the (non-interactive) output table of that node, the molecular structure svg images are correctly displayed (see attached output_table screenshot). This is also the case if I link that node output to a Javascript Table View node (see attached javascript_table screenshot).
So far, the only node I found where this is not working is the Heatmap node.

The last version where I see this working was in KNIME AP 4.6. I hope this can help in the problem diagnosis.
Should I mark this thread as solved or do you prefer to keep it open for a non-workarounded solution?



  1. Output table:

  2. Javascript table:


This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.