I new to Knime and I’ve tried Knime with a very small example.
In an Excel-Sheet there is a time series with multiple values per time entry.
I was sucessful to read the Excel table (with a read xls node) and extract three columns (using column filter):
Date stamp (column 1)
Value 1 (amount) (column 2)
Value 2 (don’t care at the moment) (column 3)
I can check the result of the second node and it looks ok.
What I would like to have is a bar chart of the value1 over time.
I tried the bar chart but it does not behave as expected:
When choosing the column 1 as x axis I always get “1” as value (nice but wrong)
If I use a line plot instead after the second node it displays the data correctly. But line plots are not suitable for my use case (I want to see the single time entries.
What do I make wrong?
Furthermore I have the problem that (with the line plot) the data on the x-axis is not readable. Is there a way to tell Knime (the line plot and also the bar chart) to make two things:
write the data on the x-axis vertical
if there is not enough space to write only evey second (or third) entry
Thanks for the welcome and you for the hint.
I tried to change the aggregation method to “sum”.
But this brings an error Execute failed: Frequency column filter include list empty. Select at least one frequency column
But the configuration does not allow to select any columns for selection (and aggregation).
So I’m still searching for the right way to use bar charts.
If no available columns to select in configuration window that means you do not have any number column types in your data set. And Sum and Average methods require numbers while Occurrence does not. If you have numbers in column type string use String to Number node prior to Bar Chart.