Need some explanation.

Hi everyone, IM new to Space Syntax, and Im trying to do simple stuff to get to understand these components. Can anyone give me a closer explanation for these components : ITG, ETR and CTR ?

I have read the "Help" and the component yellow note but didnt really get through.

Since ITG and ETR component have kinda of the same private and public ratio. So what is the different? (I dont know the word "Entropy" means)

How to change the color of rectangular from white-black to blue-red ?

Thank you so much.

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Replies to This Discussion

Permalink Reply by Pirouz Nourian on February 15, 2016 at 9:24am

Hi Bao,

I would suggest that you switch your view to Full-Name views. We have explained these measures in the papers below:

Nourian, Pirouz, Samaneh Rezvani, and Sevil Sariyildiz. "Designing ...

http://www.sss9.or.kr/paperpdf/mmd/sss9_2013_ref048_p.pdf

The measure Entropy is newer. I hereby explain it (from my PhD dissertation):

Entropy values, as described in (Hillier & Hanson, The Social Logic of Space, 1984) and specified in (Turner A. , “Depthmap: A Program to Perform Visibility Graph Analysis, 2007), intuitively describe the difficulty of getting to other spaces from a certain space. In other words, the higher the entropy value, the more difficult it is to reach other spaces from that space and vice-versa. We compute the spatial entropy of the node as using the point depth set:

(11)

“The term is the maximum depth from vertex and is the frequency of point depth *d* from the vertex” (ibid). Technically, we compute it using the function below, which itself uses some outputs and by-products from previous calculations:

Algorithm 4: Entropy Computation

Given the graph (adjacency lists), Depths as List of List of integer, DepthMap as Dictionary of integer

Initialize Entropies as List(double)

For node as integer in range [0, |V|)

integer How_Many_of_D=0
double S_node=0
For depth as integer in range [1, Depths[node].Max()]
- How_Many_of_D=DepthMap.Branch[(node,depth)].Count
- double frequency= How_Many_of_D/|V|
- S_node = S_node - frequency * Math.Log(frequency, 2)
Next
Entropies [node] = S_node