diff options
author | daney <daney@280ebfd0-de03-0410-8827-d642c229c3f4> | 2001-10-12 15:19:02 +0000 |
---|---|---|
committer | daney <daney@280ebfd0-de03-0410-8827-d642c229c3f4> | 2001-10-12 15:19:02 +0000 |
commit | c4383eb71110a8ee6fba69315c3f600320588885 (patch) | |
tree | 5367daad6a244753ea692918e631df13734a02d6 /algorithms.tex | |
parent | f8e253a8113b9abfe29b3de8291e1ea44e900899 (diff) | |
download | mpfr-c4383eb71110a8ee6fba69315c3f600320588885.tar.gz |
correction d'erreurs sur les notations + correction de la regle 9
git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@1245 280ebfd0-de03-0410-8827-d642c229c3f4
Diffstat (limited to 'algorithms.tex')
-rw-r--r-- | algorithms.tex | 40 |
1 files changed, 17 insertions, 23 deletions
diff --git a/algorithms.tex b/algorithms.tex index 79a9f960f..e14cc80b3 100644 --- a/algorithms.tex +++ b/algorithms.tex @@ -112,13 +112,17 @@ $\ulp(o(x)) \leq \ulp(x)$. \begin{Rule} \label{R9} \begin{eqnarray}\nonumber -&&\textnormal{with}\;\; u=o(x),\;\; u.(1-2^{1-p}) \leq x \leq u.(1+2^{1-p})\\\nonumber -&&\;\;\;\;\;\;\textnormal{or with}\;\; u=o(x),\;\; u.c_u^- \leq x \leq u.c_u^+\\\nonumber -&&\;\;\;\;\;\;\;\;\;\;\;\;\textnormal{if}\;\; u=\pinf(x),\n{ then } c_u^+=1\\\nonumber -&&\;\;\;\;\;\;\;\;\;\;\;\;\textnormal{if}\;\; u=\minf(x),\n{ then } c_u^-=1\\\nonumber -&&\;\;\;\;\;\;\;\;\;\;\;\;\textnormal{if}\;\; \n{for $x<0$ and } u=Z(x),\n{ then } c_u^+=1 \\\nonumber -&&\;\;\;\;\;\;\;\;\;\;\;\;\textnormal{if}\;\; \n{for $x>0$ and } u=Z(x),\n{ then } c_u^-=1 \\\nonumber -&&\;\;\;\;\;\;\;\;\;\;\;\;\textnormal{else}\;\; c_u^{-}=1-2^{1-p} \n{ and } c_u^{+}=1+2^{1-p} +&&\n{For}\;\; error(u) \leq k_u \ulp(u),\;\; u.c_u^- \leq x \leq u.c_u^+)\\\nonumber +&&\n{with}\;\; c_u^{-}=1- k_u 2^{1-p} \n{ and } c_u^{+}=1+ k_u 2^{1-p} +\end{eqnarray} + +\begin{eqnarray}\nonumber +&&\n{For}\;\; u=o(x),\;\; u.c_u^- \leq x \leq u.c_u^+\\\nonumber +&&\n{if}\;\; u=\pinf(x),\n{ then } c_u^+=1\\\nonumber +&&\n{if}\;\; u=\minf(x),\n{ then } c_u^-=1\\\nonumber +&&\n{if}\;\; \n{for $x<0$ and } u=Z(x),\n{ then } c_u^+=1 \\\nonumber +&&\n{if}\;\; \n{for $x>0$ and } u=Z(x),\n{ then } c_u^-=1 \\\nonumber +&&\n{else}\;\; c_u^{-}=1-2^{1-p} \n{ and } c_u^{+}=1+2^{1-p} \end{eqnarray} \end{Rule} @@ -568,10 +572,7 @@ is at most $(\varepsilon_k t + \tau_k y)/2^m + 1$. We want to compute the generic error of the soustraction, this following rules can be apply on addition too. \begin{eqnarray}\nonumber -u&=&o(x) \\\nonumber -v&=&o(y) \\\nonumber -w&=&o(u+v) \\\nonumber -\textnormal{Note:}&& error(u) = k_u \, \ulp(u), \;\; error(v) = k_v \, \ulp(v) +\textnormal{Note:}&& error(u) \leq k_u \, \ulp(u), \;\; error(v) \leq k_v \, \ulp(v) \end{eqnarray} \begin{eqnarray}\nonumber @@ -598,10 +599,8 @@ error(w)& \leq&(c_w + k_u + k_v) \, \ulp(w) We want to compute the generic error of the multiplication. \begin{eqnarray}\nonumber -u&=&o(x) \\\nonumber -v&=&o(y) \\\nonumber w&=&o(u.v) \\\nonumber -\textnormal{Note:}&& error(u) = k_u \, \ulp(u), \;\; error(v) = k_v \, \ulp(v) +\textnormal{Note:}&& error(u) \leq k_u \, \ulp(u), \;\; error(v) \leq k_v \, \ulp(v) \end{eqnarray} \begin{eqnarray}\nonumber error(w)& = &|w - x.y| \\\nonumber @@ -621,9 +620,8 @@ error(w)& = &|w - x.y| \\\nonumber We want to compute the generic error of the inverse. \begin{eqnarray}\nonumber -u&=&o(x) \\\nonumber w&=&o(\frac{1}{v}) \\\nonumber -\textnormal{Note:}&& error(u) = k_u \, \ulp(u) +\textnormal{Note:}&& error(u) \leq k_u \, \ulp(u) \end{eqnarray} \begin{eqnarray}\nonumber error(w)& = &|w - \frac{1}{x}| \\\nonumber @@ -650,10 +648,8 @@ error(w)& \leq & c_w \ulp(w) + c_u\frac{k_u}{u^2} \ulp(u)\\\nonumber We want to compute the generic error of the division. \begin{eqnarray}\nonumber -u&=&o(x) \\\nonumber -v&=&o(y) \\\nonumber w&=&o(\frac{u}{v}) \\\nonumber -\textnormal{Note:}&& error(u) = k_u \, \ulp(u), \;\; error(v) = k_v \, \ulp(v) +\textnormal{Note:}&& error(u) \leq k_u \, \ulp(u), \;\; error(v) \leq k_v \, \ulp(v) \end{eqnarray} \begin{eqnarray}\nonumber error(w)& = &|w - \frac{x}{y}| \\\nonumber @@ -688,9 +684,8 @@ error(w)& \leq & c_w \ulp(w) + 2.k_u \ulp(w)+ c_u.c_v.\frac{k_v u}{vv} \ulp(v)\ We want to compute the generic error of the square root. \begin{eqnarray}\nonumber -u&=&o(x) \\\nonumber v&=&o(\sqrt{u}) \\\nonumber -\textnormal{Note:}&& error(u) = k_u \, \ulp(u)\\\nonumber +\textnormal{Note:}&& error(u) \leq k_u \, \ulp(u)\\\nonumber \end{eqnarray} \begin{eqnarray}\nonumber error(v)& = &|v - \sqrt{x}| \\\nonumber @@ -719,9 +714,8 @@ error(v)& \leq & c_v \ulp(v) + We want to compute the generic error of the logarithm. \begin{eqnarray}\nonumber -u&=&o(x) \\\nonumber v&=&o(\log{u}) \\\nonumber -\textnormal{Note:}&& error(u) = k_u \, \ulp(u)\\\nonumber +\textnormal{Note:}&& error(u) \leq k_u \, \ulp(u)\\\nonumber \end{eqnarray} \begin{eqnarray}\nonumber error(v)& = &|v - \log{x}| \\\nonumber |