Hello OF team,

I have a multiple entity table with an taxon and dbh attributes. The dbh is calculated as the height value of the tallest tree in the forest, multiplicated by 3 (dbhh = ht*3). I want to use this dbh value for as a check rule value in the dbh mesure of trees in a plot. How can i refer the dbh value from another entity for each especie?



asked 25 Nov '18, 20:06

lcomas's gravatar image

accept rate: 0%

edited 25 Nov '18, 20:08

Hi Lluís,
If I understand correctly your question, this is the structure of your survey: you have an entity tree with attributes species and height and another entity tree_2 with an attribute species_2.
To simplify your calculations you can add a calculated attribute in tree_2 to store the value of the tallest tree with the same species specified in each row of tree_2 (call this attribute ht): the expression to write in the Calculated value is: math:max(parent()/tree[species = $context/species_2]/height).
Then you can define another calculated attribute dbhh with an expression like this: ht * 3.
In the end you can use the value of dbhh in a comparison check inside your dbh attribute of the tree_2 entity.
Does it fits your needs?
Many thanks,
Open Foris Team

permanent link

answered 27 Nov '18, 22:45

OF%20Collect's gravatar image

OF Collect ♦♦
accept rate: 23%

Your answer
toggle preview

Follow this question

By Email:

Once you sign in you will be able to subscribe for any updates here



Answers and Comments

Markdown Basics

  • *italic* or _italic_
  • **bold** or __bold__
  • link:[text](http://url.com/ "title")
  • image?![alt text](/path/img.jpg "title")
  • numbered list: 1. Foo 2. Bar
  • to add a line break simply add two spaces to where you would like the new line to be.
  • basic HTML tags are also supported

Question tags:


question asked: 25 Nov '18, 20:06

question was seen: 690 times

last updated: 27 Nov '18, 22:45