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--- tutorials:grogra-functions [2024/05/28 15:50] – [Available functions, their purpose and output] thomas
+++ tutorials:grogra-functions [2025/06/30 16:44] (current) – t
@@ Line 1: / Line 1: @@
 ====== GROGRA Functions for structural analysis ======
-GroIMP contains some of the functions from its predecessor GROGRA which can be used to statistically analyze the current structure (e.g. with regard to lengths, angles, ect.). These functions can be found under <key>Panels</key> -> <key>RGG Panels</key> -> <key>GROGRA Functions</key>:
+GroIMP contains some of the functions from its predecessor GROGRA which can be used to statistically analyze the current structure (e.g. with regard to lengths, angles, ect.). These functions can be found under Panels -> RGG Panels -> GROGRA Functions:
 {{:tutorials:grogra_panel.png?400|}}
-Some of these functions are also explained in this {{ :tutorials:grogra_reference_guide.pdf | initial GROGRA documentation }} (page 98f.) and some further expansions in this {{ :tutorials:dzierzon_et_al_2003.pdf | paper}} (https://doi.org/10.14214/sf.510). This wiki provides a compressed form of the information in these sources, which are outdated. Not all the functions mentioned in the GROGRA documentation are 1:1 available in GroIMP. Also some of the the features of the different functions appear to be broken or they don't work at all (at least with the basic RGG model tree). This is because they were designed for some specific purpose that was lost over time. So use them at your own discretion. You can also check out the source code of the functions [[https://gitlab.com/grogra/groimp-plugins/RGG/-/blob/master/src/main/java/de/grogra/grogra/Analysis.java?ref_type=heads | here]].
+Some of these functions are also explained in this {{ :tutorials:grogra_reference_guide.pdf | initial GROGRA documentation }} (page 98f.) and some further expansions in this {{ :tutorials:dzierzon_et_al_2003.pdf | paper}} (https://doi.org/10.14214/sf.510) and also {{ :tutorials:oppelt_kurth_godbold_2001.pdf | here}} (only topological analysis). This wiki provides a compressed form of the information in these sources, which are partially outdated. For example, not all the functions mentioned in the GROGRA documentation are 1:1 available in GroIMP. Also some of the the features of the different functions appear to be broken or they don't work at all (at least with the basic RGG model tree). This is because they were designed for some specific purpose that was lost over time. So use them at your own discretion. If you are really interested in one specific function, I recommend to check out the source code of the functions [[https://gitlab.com/grogra/groimp-plugins/RGG/-/blob/master/src/main/java/de/grogra/grogra/Analysis.java?ref_type=heads | here]] to learn what it actually does. If you find information that is not covered already by this wiki, please add it!
 ===== Available functions, their purpose and output =====
 {{:tutorials:functions.png?400|}}
-The functions are applied by clicking on their name in the <key>Analysis</key> drop-down menu. They all output a table that can be saved as e.g. .txt or .csv for further analysis in e.g. R via <key>data</key> -> <key>exporttable</key>. The <key>Analysis (shiny)</key> menu provides the same functions and is supposed to somehow integrate with R, but I could not figure out how it works. Please add this info if you find it. {{:tutorials:guertler_msc.pdf |  This thesis}} might provide some information on that.
+The functions are applied by clicking on their name in the Analysis drop-down menu. They all output a table that can be saved as e.g. .txt or .csv for further analysis in e.g. R via data -> exporttable. The Analysis (shiny) menu provides the same functions and is supposed to somehow integrate with R, but I could not figure out how it works. Please add this info if you find it. {{:tutorials:guertler_msc.pdf |  This thesis}} provides some information on that but it did not really help me (under Windows).
 This is what you can do:
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 ==== Crown layers ====
 <color #ed1c24>No documentation found and appears to be broken</color>
-GroIMP will ask for user input to define the height of horizontal "slices" in which the structure will be analyzed. When you decline the equidistant layers, it will ask for 3 layer bounds resulting in 4 layers total. When using equidistant layers, you can specify the the layer height but it will always result in a 20m overall zone (let me know if you can change this). The output should apparently contain the sum of element lengths in each layer, but in my testing all the sum only appears in layer #1, all other layers have 0 length sum.
+GroIMP will ask for user input to define the height of horizontal "slices" in which the structure will be analyzed. When you decline the equidistant layers, it will ask for 3 layer bounds resulting in 4 layers total. When using equidistant layers, you can specify the the layer height but it will always result in a 20m overall zone. The output should apparently contain the sum of element lengths in each layer, but in my testing all the sum only appears in layer #1, all other layers have 0 length sum.
 ==== Stem analysis ====
+This function provides a table with a discretized description of the main stem (= segments of branching order 0) with diameter information for different heights (= Stem taper table). In the 90s, there was a program for the Silicon Graphics workstation called GROBOL (growth of boles engine), which could display and analyze the stem using this table (I am only mentioning this here because this software pops up in the sources occasionally, but don't bother searching for it).
 ==== Distribution analysis ====
+Frequency tables: elementary units, compound units, axes, el. units per compound unit etc., in total and for each branching order. <color #ed1c24>Appears to be a bit broken, can produce some unexpected results!</color>
 ==== Topological analysis ====
+Number of components, number of (graph-theoretical) links, maximal and average topological depth and other topological parameters, see {{ :tutorials:oppelt_kurth_godbold_2001.pdf | Oppelt et al. (2001)}}
 ==== Axes analysis ====
+<color #ed1c24>Extremely broken, crashes my GroIMP every time.</color> Is supposed to give parameters for each axis, including average interbranch distance and its standard deviation.