obtain the value of an attribute from a multiple entity to use it in another multiple entity

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?

Thanks!!

Lluís

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asked 25 Nov '18, 20:06

lcomas
11●5
accept rate: 0%

edited 25 Nov '18, 20:08

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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

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answered 27 Nov '18, 22:45

Stefano (OF) ♦♦
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accept rate: 19%

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question asked: 25 Nov '18, 20:06

question was seen: 1,967 times

last updated: 27 Nov '18, 22:45

obtain the value of an attribute from a multiple entity to use it in another multiple entity

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