Feature request #19497

Rotate point symbols when "custom expression" is active

Added by Corentin CHARLOT about 2 years ago. Updated about 2 years ago.

Status:Feedback
Priority:Normal
Assignee:-
Category:Digitising
Pull Request or Patch supplied:No Resolution:
Easy fix?:No Copied to github as #:27325

Description

Hello,

When an expression is defined as a reference for the rotation angle in style properties, the "Rotate Point Symbols" tool does not work.
Only a numeric field allows its use.

My angle field must be in grad, anti-trigonometric, 0 in the East (compliance with specifications), so I need an expression to convert these values to display it right QGIS.

Another solution would be to be able to change the type of value of the angles in the project:
- degree, grad, radian
- arithmetic or geographic system
- 0 to North or 0 to East

Thank you.

expression.png - Expression (344 KB) Corentin CHARLOT, 2018-07-26 02:47 PM

History

#1 Updated by Giovanni Manghi about 2 years ago

  • Easy fix? changed from Yes to No
  • Status changed from Open to Feedback

Why feature request?

#2 Updated by Corentin CHARLOT about 2 years ago

Feature request if QGIS allows to switch between :

- degree, grad, radian
- arithmetic or geographic system
- 0 to North or 0 to East

Bug :

When an expression is defined as a reference for the rotation angle in style properties, the "Rotate Point Symbols" tool does not work.

I don't know which solution is the best and easier to fix/implement...

#3 Updated by Nyall Dawson about 2 years ago

Allowing interactive editing when an expression is set is basically impossible. It would require that qgis had an expression solver which could reverse an expression to calculate the value which must be saved in a particular field. It'd only work for expressions which are reversible and which use a single field. In short, a huge amount of effort for little reward.

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