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| author | Juan Marín Noguera <juan.marinn@um.es> | 2021-01-05 14:02:07 +0100 |
|---|---|---|
| committer | Juan Marín Noguera <juan.marinn@um.es> | 2021-01-05 14:02:07 +0100 |
| commit | bfcfc8ba9f45c60c08093a8cd5afb71ffae32be2 (patch) | |
| tree | f9cfc35e234e4f7d61b66f3cfd47b9eb3255adba /mne | |
| parent | 0e00247df826ea2a161231423a2993b63383f11b (diff) | |
Introducción MNED
Diffstat (limited to 'mne')
| -rw-r--r-- | mne/n.lyx | 156 | ||||
| -rw-r--r-- | mne/n1.lyx | 462 |
2 files changed, 618 insertions, 0 deletions
diff --git a/mne/n.lyx b/mne/n.lyx new file mode 100644 index 0000000..e411df6 --- /dev/null +++ b/mne/n.lyx @@ -0,0 +1,156 @@ +#LyX 2.3 created this file. For more info see http://www.lyx.org/ +\lyxformat 544 +\begin_document +\begin_header +\save_transient_properties true +\origin unavailable +\textclass book +\begin_preamble +\input{../defs} +\end_preamble +\use_default_options true +\maintain_unincluded_children false +\language spanish +\language_package default +\inputencoding auto +\fontencoding global +\font_roman "default" "default" +\font_sans "default" "default" +\font_typewriter "default" "default" +\font_math "auto" "auto" +\font_default_family default +\use_non_tex_fonts false +\font_sc false +\font_osf false +\font_sf_scale 100 100 +\font_tt_scale 100 100 +\use_microtype false +\use_dash_ligatures true +\graphics default +\default_output_format default +\output_sync 0 +\bibtex_command default +\index_command default +\paperfontsize 10 +\spacing single +\use_hyperref false +\papersize a5paper +\use_geometry true +\use_package amsmath 1 +\use_package amssymb 1 +\use_package cancel 1 +\use_package esint 1 +\use_package mathdots 1 +\use_package mathtools 1 +\use_package mhchem 1 +\use_package stackrel 1 +\use_package stmaryrd 1 +\use_package undertilde 1 +\cite_engine basic +\cite_engine_type default +\biblio_style plain +\use_bibtopic false +\use_indices false +\paperorientation portrait +\suppress_date false +\justification true +\use_refstyle 1 +\use_minted 0 +\index Index +\shortcut idx +\color #008000 +\end_index +\leftmargin 0.2cm +\topmargin 0.7cm +\rightmargin 0.2cm +\bottommargin 0.7cm +\secnumdepth 3 +\tocdepth 3 +\paragraph_separation indent +\paragraph_indentation default +\is_math_indent 0 +\math_numbering_side default +\quotes_style swiss +\dynamic_quotes 0 +\papercolumns 1 +\papersides 1 +\paperpagestyle empty +\listings_params "basicstyle={\ttfamily}" +\tracking_changes false +\output_changes false +\html_math_output 0 +\html_css_as_file 0 +\html_be_strict false +\end_header + +\begin_body + +\begin_layout Title +Métodos Numéricos de las Ecuaciones Diferenciales +\end_layout + +\begin_layout Date +\begin_inset Note Note +status open + +\begin_layout Plain Layout + +\end_layout + +\end_inset + + +\end_layout + +\begin_layout Standard +\begin_inset ERT +status open + +\begin_layout Plain Layout + + +\backslash +def +\backslash +cryear{2020} +\end_layout + +\end_inset + + +\end_layout + +\begin_layout Standard +\begin_inset CommandInset include +LatexCommand input +filename "../license.lyx" + +\end_inset + + +\end_layout + +\begin_layout Standard +Bibliografía: +\end_layout + +\begin_layout Itemize +Notas de clase. +\end_layout + +\begin_layout Chapter +Introducción +\end_layout + +\begin_layout Standard +\begin_inset CommandInset include +LatexCommand input +filename "n1.lyx" + +\end_inset + + +\end_layout + +\end_body +\end_document diff --git a/mne/n1.lyx b/mne/n1.lyx new file mode 100644 index 0000000..bc4abd2 --- /dev/null +++ b/mne/n1.lyx @@ -0,0 +1,462 @@ +#LyX 2.3 created this file. For more info see http://www.lyx.org/ +\lyxformat 544 +\begin_document +\begin_header +\save_transient_properties true +\origin unavailable +\textclass book +\use_default_options true +\maintain_unincluded_children false +\language spanish +\language_package default +\inputencoding auto +\fontencoding global +\font_roman "default" "default" +\font_sans "default" "default" +\font_typewriter "default" "default" +\font_math "auto" "auto" +\font_default_family default +\use_non_tex_fonts false +\font_sc false +\font_osf false +\font_sf_scale 100 100 +\font_tt_scale 100 100 +\use_microtype false +\use_dash_ligatures true +\graphics default +\default_output_format default +\output_sync 0 +\bibtex_command default +\index_command default +\paperfontsize default +\spacing single +\use_hyperref false +\papersize default +\use_geometry false +\use_package amsmath 1 +\use_package amssymb 1 +\use_package cancel 1 +\use_package esint 1 +\use_package mathdots 1 +\use_package mathtools 1 +\use_package mhchem 1 +\use_package stackrel 1 +\use_package stmaryrd 1 +\use_package undertilde 1 +\cite_engine basic +\cite_engine_type default +\biblio_style plain +\use_bibtopic false +\use_indices false +\paperorientation portrait +\suppress_date false +\justification true +\use_refstyle 1 +\use_minted 0 +\index Index +\shortcut idx +\color #008000 +\end_index +\secnumdepth 3 +\tocdepth 3 +\paragraph_separation indent +\paragraph_indentation default +\is_math_indent 0 +\math_numbering_side default +\quotes_style french +\dynamic_quotes 0 +\papercolumns 1 +\papersides 1 +\paperpagestyle default +\tracking_changes false +\output_changes false +\html_math_output 0 +\html_css_as_file 0 +\html_be_strict false +\end_header + +\begin_body + +\begin_layout Standard +Un +\series bold +problema de valores iniciales +\series default + real es uno de la forma +\begin_inset Formula +\[ +\left\{ \begin{aligned}\dot{x} & =f(t,x),\\ +x(t_{0}) & =x_{0}, +\end{aligned} +\right. +\] + +\end_inset + +dado por +\begin_inset Formula $f:\Omega\subseteq\mathbb{R}\times\mathbb{R}^{n}\to\mathbb{R}^{n}$ +\end_inset + + con +\begin_inset Formula $\Omega$ +\end_inset + + abierto y +\begin_inset Formula $(t_{0},x_{0})\in\Omega$ +\end_inset + +, y donde +\begin_inset Formula $x:I\subseteq\mathbb{R}\to\mathbb{R}^{n}$ +\end_inset + + es la incógnita, siendo +\begin_inset Formula $I$ +\end_inset + + un entorno de +\begin_inset Formula $t_{0}$ +\end_inset + +. + +\end_layout + +\begin_layout Standard +El problema está +\series bold +bien planteado +\series default + en un intervalo +\begin_inset Formula $[a,b]\subseteq I$ +\end_inset + + si tiene solución única en +\begin_inset Formula $[a,b]$ +\end_inset + + y para todo +\begin_inset Formula $\varepsilon>0$ +\end_inset + + existe un +\begin_inset Formula $\delta>0$ +\end_inset + + tal que si +\begin_inset Formula $c\in(-\varepsilon,\varepsilon)$ +\end_inset + + y +\begin_inset Formula $e:[a,b]\to\mathbb{R}^{n}$ +\end_inset + + es tal que +\begin_inset Formula $|e(t)|<\varepsilon$ +\end_inset + + para todo +\begin_inset Formula $t\in[a,b]$ +\end_inset + +, entonces el +\series bold +problema perturbado +\series default + +\begin_inset Formula +\[ +\left\{ \begin{aligned}\dot{z} & =f(t,z)+e(t),\\ +z(t_{0}) & =x_{0}+c, +\end{aligned} +\right. +\] + +\end_inset + +tiene solución única. +\end_layout + +\begin_layout Standard +Como +\series bold +teorema +\series default +, si +\begin_inset Formula $D:=[a,b]\times\mathbb{R}$ +\end_inset + +, +\begin_inset Formula $t_{0}\in[a,b]$ +\end_inset + + y +\begin_inset Formula $f:D\to\mathbb{R}$ +\end_inset + + es continua y lipschitziana en la segunda variable en todo +\begin_inset Formula $D$ +\end_inset + +, entonces +\begin_inset Formula +\[ +\left\{ \begin{aligned}\dot{x} & =f(t,x),\\ +x(t_{0}) & =x_{0} +\end{aligned} +\right. +\] + +\end_inset + +está bien planteado. +\end_layout + +\begin_layout Standard +En adelante supondremos que el dominio de +\begin_inset Formula $x$ +\end_inset + + incluye un intervalo +\begin_inset Formula $[a,b]$ +\end_inset + + y +\begin_inset Formula $t_{0}=a$ +\end_inset + +. + No siempre se puede resolver un problema de valores iniciales de forma + analítica, por lo que usamos métodos de resolución numérica, que aproximan + +\begin_inset Formula $x|_{[a,b]}$ +\end_inset + + creando una partición +\begin_inset Formula $a=t_{0}<\dots<t_{n}=c$ +\end_inset + +, para un cierto +\begin_inset Formula $c\geq b$ +\end_inset + + con +\begin_inset Formula $[a,c]$ +\end_inset + + en el dominio de +\begin_inset Formula $x$ +\end_inset + +, y obtienen una secuencia +\begin_inset Formula $(\omega_{i})_{i=0}^{n}$ +\end_inset + + que aproxima +\begin_inset Formula $(x(t_{i}))_{i=0}^{n}$ +\end_inset + + con un error +\begin_inset Formula $\max_{i=0}^{n}\Vert x(t_{i})-\omega_{i}\Vert$ +\end_inset + + aceptable. + Los valores de +\begin_inset Formula $x$ +\end_inset + + en el resto de puntos de +\begin_inset Formula $[a,b]$ +\end_inset + + se obtienen por interpolación. +\end_layout + +\begin_layout Standard +\begin_inset ERT +status open + +\begin_layout Plain Layout + + +\backslash +sremember{CN} +\end_layout + +\end_inset + + +\end_layout + +\begin_layout Standard +Si el polinomio interpolador de +\begin_inset Formula $f$ +\end_inset + + en +\begin_inset Formula $x_{0},\dots,x_{n}$ +\end_inset + + es +\begin_inset Formula $P(x)=a_{n}x^{n}+\dots+a_{0}$ +\end_inset + +, llamamos +\begin_inset Formula $f[x_{0},\dots,x_{n}]:=a_{n}$ +\end_inset + +. + [...] +\begin_inset Formula $f[x]=f(x)$ +\end_inset + +. + [...] Para +\begin_inset Formula $n\geq1$ +\end_inset + +, +\begin_inset Formula +\[ +f[x_{0},\dots,x_{n}]=\frac{f[x_{1},\dots,x_{n}]-f[x_{0},\dots,x_{n-1}]}{x_{n}-x_{0}}. +\] + +\end_inset + +[...] Una forma de hallar +\begin_inset Formula $f[x_{0},\dots,x_{n}]$ +\end_inset + + es usando una tabla triangular que se va llenando por columnas, donde la + primera columna contiene los +\begin_inset Formula $x_{k}$ +\end_inset + +, la segunda, los +\begin_inset Formula $f(x_{k})$ +\end_inset + +, [...], y la +\begin_inset Formula $j$ +\end_inset + +-ésima, los +\begin_inset Formula $f[x_{k-j+1},\dots,x_{k}]$ +\end_inset + +, llegando a +\begin_inset Formula $f[x_{0},\dots,x_{n}]$ +\end_inset + + en la +\begin_inset Formula $(n+1)$ +\end_inset + +-ésima fila. +\end_layout + +\begin_layout Standard +[...] +\series bold +Forma de Newton +\series default + del polinomio interpolador, [...] +\begin_inset Formula +\[ +f[x_{0}]+f[x_{0},x_{1}](x-x_{0})+\dots+f[x_{0},\dots,x_{n}](x-x_{0})\cdots(x-x_{n-1}). +\] + +\end_inset + +Para cálculo computacional es más apropiada la forma anidada, +\begin_inset Formula +\[ +f[x_{0}]+(x-x_{0})(f[x_{0},x_{1}]+(x-x_{1})(f[x_{0},x_{1},x_{2}]+\dots)). +\] + +\end_inset + + +\end_layout + +\begin_layout Standard +[...] Un +\series bold +problema de Hermite +\series default + consiste en hallar un polinomio +\begin_inset Formula $P$ +\end_inset + + de grado +\begin_inset Formula $N$ +\end_inset + + tal que, para +\begin_inset Formula $k\in\{0,\dots,m\}$ +\end_inset + + y +\begin_inset Formula $x\in S_{k}$ +\end_inset + +, +\begin_inset Formula $P^{(k)}(x)=f^{(k)}(x)$ +\end_inset + +. +\end_layout + +\begin_layout Standard +Existe un único polinomio de grado máximo +\begin_inset Formula $\sum_{k=0}^{m}|S_{k}|$ +\end_inset + + que cumpla las condiciones, y podemos hallarlo mediante +\series bold +diferencias divididas generalizadas +\series default +. + Si +\begin_inset Formula $x_{0}\leq\dots\leq x_{n}$ +\end_inset + +, [...] +\begin_inset Formula +\[ +f[x_{0},\dots,x_{n}]:=\begin{cases} +\frac{f[x_{1},\dots,x_{n}]-f[x_{0},\dots,x_{n-1}]}{x_{n}-x_{0}}, & x_{0}<x_{n};\\ +\frac{f^{(n)}(x_{0})}{n!}, & x_{0}=\dots=x_{n}. +\end{cases} +\] + +\end_inset + +Creamos una tabla de diferencias divididas en la que cada elemento +\begin_inset Formula $x\in S_{0}$ +\end_inset + + aparece tantas veces como conjuntos de entre +\begin_inset Formula $S_{0},\dots,S_{m}$ +\end_inset + + lo contienen, y expresamos el polinomio resultante [...] en forma de Newton. +\end_layout + +\begin_layout Standard +\begin_inset ERT +status open + +\begin_layout Plain Layout + + +\backslash +eremember +\end_layout + +\end_inset + + +\end_layout + +\end_body +\end_document |
