Using double offset in QGIS Expression String Builder?

Question

I need to dynamically translate points 20 metres from their original point to a suitable cartographic position. I have a rotation value stored in a rotation attribute.

I cannot use this tool right because I cannot give values when using the function cos ("rotation") * 20 or sin ("rotation") * 20

Only number inside ' (single quotation marks) are accepted. How I can use function inside double offset definition?

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Sorry about Finnish interface!

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• Erik: If you add a textfield to the feature containing something like 20,50 the offset works.

Answer 1

You need to transform each number into string representations, and combine those with a comma. Based on your screenshot above, the proper expression would be:

to_string(cos("rotation")*20) || ',' || to_string(sin("rotation")*20)

• Mickeler: yes, exactly! Thanks very much! =)