From a1a35eeafaa09694a4439417613b42ccac931890 Mon Sep 17 00:00:00 2001 From: Jean Sirmai Date: Thu, 1 Apr 2021 11:06:58 +0000 Subject: [PATCH] Update README.md --- README.md | 87 +++++++++++++++++++++++++------------------------------ 1 file changed, 39 insertions(+), 48 deletions(-) diff --git a/README.md b/README.md index 79b3cf1..1c86c91 100644 --- a/README.md +++ b/README.md @@ -1,25 +1,41 @@ # gem-graph is for: GE-ometric directed M-ulti-GRAPH -- A geometric graph is a graph whose nodes have coordinates in a space +>#### (1) A ***geometric*** graph is a graph whose nodes have coordinates in a space +>#### (2) It is ***directed*** if its bonds are arrows +>#### (3) It is a ***multi***graph if multiple arrows can be stacked from the same node to another +>##### Note that 'directed' does not means 'oriented': a graph is oriented if one of its nodes is its root -- A graph is directed if its bonds are arrows +--- -- It is a multigraph if several arrows can be stacked from one node to another one +#### ***Geometric directed multigraphs*** have properties that make them suitable for the representation of complex phenomena. +#### ***gem-graph*** is a software that enables modelling with a geometric directed multigraph. -- Note that 'directed' does not means 'oriented': a graph is oriented if one of its nodes is its root +## ______________________________________________________________________________________________________________ - -Geometric directed multigraphs have properties that make them suitable for the representation of complex phenomena, -especially those where numerous different objects and types of interactions are involved. - - -gem-graph is a software that enables modelling with a geometric directed multigraph. - - -today (28-03-2011) two texts are under development: -* questions about the [architecture](architecture.md): identification and naming of the main parts of this program -* [theoretical issues](theory.md) : Rewritten Geometric Directed Multigraphs Properties. (JS dec 2017) - This text could be a starting point for a publication +### Faced with the difficulty of calculating the evolution of complex systems defined by +- a great diversity of objects and +- a great diversity of interactions, +### **The gem-graph rationale is:** +#### 1. represent space +#### 2. a discreet (non-continuous) space +#### 3. a space whose all units are similar +#### 4. links can be established between some of these units +- they allow drawing **objects** (isolated connex parts of the graph) and **situations** (relative positions of objects) +- for practical purposes, it is convenient to use **arrows** and to allow stacking many of them from the same node to another +#### 5. an automaton, i.e. a set of states and transitions can rewrite this space +#### 6. ***states*** can represent ***space*** +- here, **space** can be understand as **a representation or approximation of a real space** +- but a **state** can be a **space** as well as a text or any other set of symbols or writings (ex: tags) that can be drawn in the graph using the same encoding and a **state** can be an association of both. +#### 7. transitions are all combinations of ***a single type of elementary transition*** +#### 8. the coding of static information (states) and dynamic information (transitions) is distinct +- the purpose of this restriction is to maintain a strict **homogeneity of the rules** (cf. §7) which is the condition of their automatic management and edition. +#### 9. no constraint on granularity: the scope of the arrows between space units is not limited +#### 10. the computation is local, random, asynchronous +#### 11. interfaces are possible with statistical and / or continuous fermion models: +- spaces are then superimposed and conditions on intensive local variables (concentrations, temperatures, flows, etc...) can be added to the specific conditions of the gem-graph. +#### 12. interfaces are possible with representations of bosons: +- spaces are then superimposed and conditions on intensive local variables (flux, cross section, etc.) can be added to the specific conditions of the gem-graph. +#### 13. the topology, the dimension and the magnitude of the space are not constrained --- @@ -31,39 +47,14 @@ today (28-03-2011) two texts are under development: --- -**Justification de gem-graph:** -face à la difficulté de calculer les systèmes complexes définis par -- grande diversité des objets -- grande diversité des interactions, +#### Design: two converging, complementary and interdependent approaches: +- one goes **from** the available data structures and algorithms **to** the graph structure and the automaton it supports (synthetic or bottom-up approach) +- the other goes **from** the gem-graph automaton constraints **to** the available software tools (analytical or top-down approach) -**une suite de choix:** -1. représenter l'espace -2. un espace discret -3. un espace divisé en unités toutes semblables -4. des liens entre certaines de ces unités -5. utiliser un automate, i.e. un ensemble d'états et de transitions -6. les états représent l'espace -7. les transitions sont toutes des combinaisons d'un seul type de transition élémentaire -8. le codage des informations statiques (les états) et dynamiques (les transitions) est distinct - conséquence: les états ne sont pas restreints à la représentation de l'espace - ils peuvent inclure d'autres écritures utilisant le même encodage (ex: tags) -9. pas de contrainte sur la granularité: - la portée des liens entre unités de l'espace n'est pas limitée -10. le calcul est local, aléatoire, asynchrone -11. des interfaces sont possibles avec les modèles à fermions statistiques et / ou continus: - les espaces sont superposés - et des conditions sur des variables locales intensives (concentrations, températures, débits...) - peuvent être ajoutées aux conditions propres du gem-graph -12. des interfaces sont possibles avec des représentations de bosons: - les espaces sont superposés - et des conditions sur des variables locales intensives (flux, section efficace...) -13. la topologie, la dimension et la grandeur de l'espace ne sont pas contraintes - ---- - -**Deux démarches convergentes:** -- l'une va des outils disponibles vers le mécanisme (démarche synthétique ou bottom-up) -- l'autre va du mécanisme vers les outils (démarche analytique ou top-down) +#### today (28-03-2011) two texts are under development: +* questions about the [architecture](architecture.md): identification and naming of the main parts of this program and data structures +* [theoretical issues](theory.md) : Rewritten Geometric Directed Multigraphs Properties. (JS. dec 2017) + This text could be a starting point for a publication ---