Warning message

KNIME Analytics Platform
1

Hello! What does the “Garbage at end of rule detected” warning message mean?

2

Hi @Abdelrhim,

When does this warning message show up? If you are trying to use Math operations in Rule Engine node, then it is not possible.

Thanks.

3

Thanks for responding!
I am trying to create a new column in a table based on conditions and values in other tables and the message pops up when I write the conditional statement in Rule Engine.

4

Hi,
Can you share the rules you are using? The rule engine expects rule of the form condition => result. The condition is a logical expression resulting in TRUE or FALSE. If the condition is TRUE, the result on the other side of the arrow is returned. If in addition to the result you have something else there, you will see the message you reported. Please be aware that the right side of the arrow cannot be an expression, just a static value. So a rule like $A$ = 5 => $B$ + 10 does not work. Here I assume the + 10 would be seen as “garbage”.
Kind regards,
Alexander

5

Thanx Alexander
Here is what I am struggling with:
$Color$ = “yellow” AND $Size$ = “small” =>$Class$ = “inflated”

6

Hi,
Ah, I see. The problem is the $Class$ = “inflated”. Instead, just use $Color$ = “yellow” AND $Size$ = “small” => “inflated” and at the bottom of the dialog, choose “Class” as the name of the output column.
Kind regards,
Alexander

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7

Thanks!
Although no warning message appears, the values table Class is missing.

8

Hi,
The equality check is case sensitive. Are you sure that the columns contain exactly the values you have in your rules? A leading or trailing space may also make the condition not match, because " yellow " is not equal to “yellow”. To catch all cases where no other rule matches and to avoid missing values, it is recommended to add a rule like TRUE => "default value" as the last rule. This is a “catch all” rule because TRUE always evaluates to TRUE and therefore if no other condition matches, this one does and outputs the default value (which of course you can change to anything you like).
Kind regards,
Alexander

9

Thanks! It worked.
You were right about the case of equality case sensitive.

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