X-Git-Url: https://bilbo.iut-bm.univ-fcomte.fr/and/gitweb/ancetre.git/blobdiff_plain/5e17bc6675db329838a7a6902e3956f16cfbbcf1..eac3a247705e37bd82afe3300e3482c34468b917:/classEquiv.tex diff --git a/classEquiv.tex b/classEquiv.tex index 5d9f19d..b77c51a 100644 --- a/classEquiv.tex +++ b/classEquiv.tex @@ -2,41 +2,40 @@ This step considers as input the set $\{((g_1,g_2),r_{12}), (g_1,g_3),r_{13}), (g_{n-1},g{n}),r_{n-1.n})\}$ of $\frac{n(n-1)}{2}$ elements. Each one $(g_i,g_j),r_{ij})$ where $i < j$, -is a pair that gives the similarity rate $r_{ij}$ between the genes -$g_{i}$ and $g_{j}$ in $G$. +is a pair that gives the similarity rate $r_{ij}$ between the two genes +$g_{i}$ and $g_{j}$. The first step of this stage consists in building the following non-oriented -graph furthere denoted as to \emph{similarity graphe}. +graph further denoted as to \emph{similarity graph}. In this one, the vertices are the genes. There is an edge between $g_{i}$ and $g_{j}$ if the rate $r_{ij}$ is greater than a given similarity -treeshold $t$. +threshold $t$. -We then define the relation $\sim \in G \times G $ such that +We then define the relation $\sim$ such that $ x \sim y$ if $x$ and $y$ belong in the same connected component. Mathematically speaking, it is obvious that this defines an equivalence relation. -Let $\dot{x}= \{y \in G | x \sim y\}$ +Let $\dot{x}= \{y | x \sim y\}$ denotes the equivalence class to which $x$ belongs. -All the elements of $G$ which are equivalent to each other +All the genes which are equivalent to each other are also elements of the same equivalence class. -Let us then consider the set of all equivalence classes of $G$ -by $\sim$, denoted $X/\sim = \{\dot{x} | x \in G\}$. -We then consider the projection $\pi: G \to G/\mathord{\sim}$ -defined by \pi(x) = \dot{x} -which maps elements of $G$ into their respective equivalence classes by $\sim$. +Let us then consider the set of all equivalence classes of the set of genes +by $\sim$, denoted $X/\sim = \{\dot{x} | x \textrm{ is a gene}\}$. +defined by $\pi(x) = \dot{x}$ +which maps each gene into it respective equivalence class by $\sim$. -For each genome $G=[g_l,\ldot,g{l+m}]$, the second step computes +For each genome $[g_l,\ldots,g{l+m}]$, the second step computes the projection of each gene according to $\pi$. -Let $G'$ the resulting genome which is +The resulting genome which is $$ -G'=[\pi(g_l),\ldot,\pi(g{l+m})] +[\pi(g_l),\ldots,\pi(g{l+m})] $$ -is of size $m$. +is again of size $m$. -Intuitivelly speaking, for two genes $g_i$ and $g_j$ +Intuitively speaking, for two genes $g_i$ and $g_j$ in the same equivalence class, there is path from $g_i$ and $g_j$. It signifies that each evolution step (represented by an edge in the similarity graph) @@ -44,3 +43,13 @@ has produced a gene s.t. the similarity with the previous one is greater than $t$. Genes $g_i$ and $g_j$ may thus have a common ancestor. + +We compute the core genome as follow. +Each genome is projected according to $\pi$. We then consider the +intersection of all the projected genomes which are considered as sets of genes +and not as sequences of genes. +This results as the set of all the class $\dot{x}$ +such that each genome has an gene $x$ in $\dot{x}$. +The pan genome is computed similarly: the union of all the +projected genomes in computed here. +