From: Raphaël Couturier Date: Sun, 5 May 2019 12:54:55 +0000 (+0200) Subject: new X-Git-Url: https://bilbo.iut-bm.univ-fcomte.fr/and/gitweb/book_chic.git/commitdiff_plain/aa1b170823c8a4d945f63afb79f822f5d049fcd6?ds=sidebyside new --- diff --git a/chapter2.tex b/chapter2.tex index 41a299b..06da12d 100644 --- a/chapter2.tex +++ b/chapter2.tex @@ -384,16 +384,16 @@ The following dual numerical situation clearly illustrates this: \center \begin{tabular}{|l|c|c|c|}\hline \diagbox[width=4em]{$a_1$}{$b_1$}& - 1 & 0 & marge\\ \hline + 1 & 0 & margin\\ \hline 1 & 96 & 4& 100 \\ \hline 0 & 50 & 50& 100 \\ \hline - marge & 146 & 54& 200 \\ \hline + margin & 146 & 54& 200 \\ \hline \end{tabular} ~ ~ ~ ~ ~ ~ ~ \begin{tabular}{|l|c|c|c|}\hline \diagbox[width=4em]{$a_2$}{$b_2$}& - 1 & 0 & marge\\ \hline + 1 & 0 & margin\\ \hline 1 & 94 & 6& 100 \\ \hline 0 & 52 & 48& 100 \\ \hline - marge & 146 & 54& 200 \\ \hline + margin & 146 & 54& 200 \\ \hline \end{tabular} \caption{Numeric example of difference between implication and @@ -1037,3 +1037,56 @@ is the conditional entropy relative to the boxes $(\neg a \wedge \neg b)$ and $( These entropies, with values in $[0,1]$, should therefore be simultaneously weak and therefore the asymmetries between situations $S_1$ and $S_1'$ (resp. $S_2$ and $S_2'$) should be simultaneously strong if one wishes to have a good criterion for including $A$ in $B$. Indeed, entropies represent the average uncertainty of experiments that consist in observing whether b is performed (or not a is performed) when a (or not b) is observed. The complement to 1 of this uncertainty therefore represents the average information collected by performing these experiments. The more important this information is, the stronger is the guarantee of the quality of the involvement and its counterpart. We must now adapt this entropic numerical criterion to the model expected in the different cardinal situations. For the model to have the expected meaning, it must satisfy, in our opinion, the following epistemological constraints: + +\begin{enumerate} +\item It shall integrate the entropy values and, to contrast them, for example, integrate these values into the square. +\item As this square varies from 0 to 1, in order to denote the imbalance and therefore the inclusion, in order to oppose entropy, the value retained will be the complement to 1 of its square as long as the number of counter-examples is less than half of the observations of a (resp. non b). + Beyond these values, as the implications no longer have an inclusive meaning, the criterion will be assigned the value 0. +\item In order to take into account the two information specific to $a\Rightarrow b$ and $\neg b \Rightarrow \neg a$, the product will report on the simultaneous quality of the values retained. +The product has the property of cancelling itself as soon as one of its terms is cancelled, i.e. as soon as this quality is erased. +\item Finally, since the product has a dimension 4 with respect to entropy, its fourth root will be of the same dimension. +\end{enumerate} + +Let $\alpha=\frac{n_a}{n}$ be the frequency of a and $\overline{b}=\frac{n_{\overline{b}}}{n}$ be the frequency of non b. +Let $t=\frac{n_{a \wedge \overline{b}}}{n}$ be the frequency of counter-examples, the two significant terms of the respective qualities of involvement and its counterpart are: + +\begin{eqnarray*} + h_1(t) = H(b\mid a) = - (1-\frac{t}{\alpha}) log_2 (1-\frac{t}{\alpha}) - \frac{t}{\alpha} log_2 \frac{t}{\alpha} & \mbox{ if }t \in [0,\frac{\alpha}{2}[\\ + h_1(t) = 1 & \mbox{ if }t \in [\frac{\alpha}{2},\alpha]\\ + h_2(t)= H(\overline{a}\mid \overline{b}) = - (1-\frac{t}{\overline{\beta}}) log_2 (1-\frac{t}{\overline{\beta}}) - \frac{t}{\overline{b}} log_2 \frac{t}{\overline{b}} & \mbox{ if }t \in [0,\frac{\overline{\beta}}{2}[\\ + h_2(t)= 1 & \mbox{ if }t \in [\frac{\overline{\beta}}{2},\overline{\beta}] +\end{eqnarray*} +Hence the definition for determining the entropic criterion: +\definition: The inclusion index of A, support of a, in B, support of b, is the number: +$$i(a,b) = \left[ (1-h_1^2(t)) (1-h_2^2(t))) \right]^{\frac{1}{4}}$$ + +which integrates the information provided by the realization of a small number of counter-examples, on the one hand to the rule $a \Rightarrow b$ and, on the other hand, to the rule $\neg b \Rightarrow \neg a$. + +\subsection{The implication-inclusion index} + +The intensity of implication-inclusion (or entropic intensity), a new measure of inductive quality, is the number: + +$$\psi(a,b)= \left[ i(a,b).\varphi(a,b) \right]^{\frac{1}{2}}$$ +which integrates both statistical surprise and inclusive quality. + +The function $\psi$ of the variable $t$ admits a representation that has the shape indicated in Figure 4{\bf TO CHANGE}, for $n_a$ and $n_b$ fixed. +Note in this figure the difference in the behaviour of the function with respect to the conditional probability $P(B\mid A)$, a fundamental index of other rule measurement models, for example in Agrawal. +In addition to its linear, and therefore not very nuanced nature, this probability leads to a measure that decreases too quickly from the first counter-examples and then resists too long when they become important. + + +{\bf FIGURE 4} + + +\noindent Example 1\\ + \begin{tabular}{|c|c|c|c|}\hline + & $b$ & $\overline{b}$ & margin\\ \hline + $a$ & 200 & 400& 600 \\ \hline + $\overline{a}$ & 600 & 2800& 3400 \\ \hline + margin & 800 & 3200& 4000 \\ \hline + \end{tabular} + \\ + In Example 1, implication intensity is $\varphi(a,b)=0.9999$ (with $q(a,\overline{b})=-3.65$). + The entropic values of the experiment are $h_1=h_2=0$. + The value of the moderator coefficient is therefore $i(a,b)=0$. + Hence, $\psi(a,b)=0$ whereas $P(B\mid A)=0.33$. +Thus, the "entropic" functions "moderate" the intensity of implication in this case where inclusion is poor.