BAR CHART (Javascript) issue: wrong y axis scale and bar labels

KNIME Analytics Platform
1

Hi,

i'm using the node BAR CHART (Javascript) to display a labeled interactve bar chart from a simple table of two columns (label, value).

Label is a letter, value is a normalized frequency (between 0,1 e.g. a percentage), and i've set sum as aggregation method for y axis.

When i check the graph after execution (image and interactive view) i see that the y axis scale and the labels that are displayed on mouse over bars are wrong (all is set to 0.0 or 0.1, while i'm expecting all values in the range 0,1)...

Please see the attachment.

Am i missing something?

Please let me know, thank you!

Ema

2

Hi there

I had a try and have to confirm that the Y axis beheaves strange..

My attempts to get it right were not working either.. :-(

3

Hi Ema,

Thank you for reporting this. The problem is that the bar chart labels only show one decimal digit, additional digits are rounded. Therefore, a value of 0.019 will be displayed as 0.0. Since your data is in a range of 0.001 - 0.127, the chart only shows 0.0 and 0.1. Fortunately, there is already a ticket open for this, so our developers will fix it.

Cheers,

Roland

4

Hi, thank you very much for your feedback! Yes, seems to be a rounding problem...


I can use a workaround for now: i'm generating bar chart with "javascript generic view" node using "PLOTLY" as graphic engine, as described here (step by step tutorial):

http://marcoghislanzoni.com/blog/2016/04/29/knime-3-charting-with-plotly-js/

may be it can help if someone has the same issue (i know "javascript generic view" is not so easy to use beacuase you have to write a code inside the node, but it works!),... hope the problem can be fixed in next Knime updates...

thanks again
Ema