\section{Lookup$<$ Input\+Data\+Type, Output\+Data\+Type $>$ Class Template Reference} \label{classmlpack_1_1ann_1_1Lookup}\index{Lookup$<$ Input\+Data\+Type, Output\+Data\+Type $>$@{Lookup$<$ Input\+Data\+Type, Output\+Data\+Type $>$}} The \doxyref{Lookup}{p.}{classmlpack_1_1ann_1_1Lookup} class stores word embeddings and retrieves them using tokens. \subsection*{Public Member Functions} \begin{DoxyCompactItemize} \item \textbf{ Lookup} (const size\+\_\+t vocab\+Size=0, const size\+\_\+t embedding\+Size=0) \begin{DoxyCompactList}\small\item\em Create the \doxyref{Lookup}{p.}{classmlpack_1_1ann_1_1Lookup} object using the specified vocabulary and embedding size. \end{DoxyCompactList}\item {\footnotesize template$<$typename eT $>$ }\\void \textbf{ Backward} (const arma\+::\+Mat$<$ eT $>$ \&, const arma\+::\+Mat$<$ eT $>$ \&gy, arma\+::\+Mat$<$ eT $>$ \&g) \begin{DoxyCompactList}\small\item\em Ordinary feed backward pass of a neural network, calculating the function f(x) by propagating x backwards trough f. \end{DoxyCompactList}\item Output\+Data\+Type const \& \textbf{ Delta} () const \begin{DoxyCompactList}\small\item\em Get the delta. \end{DoxyCompactList}\item Output\+Data\+Type \& \textbf{ Delta} () \begin{DoxyCompactList}\small\item\em Modify the delta. \end{DoxyCompactList}\item size\+\_\+t \textbf{ Embedding\+Size} () const \begin{DoxyCompactList}\small\item\em Get the length of each embedding vector. \end{DoxyCompactList}\item {\footnotesize template$<$typename eT $>$ }\\void \textbf{ Forward} (const arma\+::\+Mat$<$ eT $>$ \&input, arma\+::\+Mat$<$ eT $>$ \&output) \begin{DoxyCompactList}\small\item\em Ordinary feed forward pass of a neural network, evaluating the function f(x) by propagating the activity forward through f. \end{DoxyCompactList}\item {\footnotesize template$<$typename eT $>$ }\\void \textbf{ Gradient} (const arma\+::\+Mat$<$ eT $>$ \&input, const arma\+::\+Mat$<$ eT $>$ \&error, arma\+::\+Mat$<$ eT $>$ \&gradient) \begin{DoxyCompactList}\small\item\em Calculate the gradient using the output delta and the input activation. \end{DoxyCompactList}\item Output\+Data\+Type const \& \textbf{ Gradient} () const \begin{DoxyCompactList}\small\item\em Get the gradient. \end{DoxyCompactList}\item Output\+Data\+Type \& \textbf{ Gradient} () \begin{DoxyCompactList}\small\item\em Modify the gradient. \end{DoxyCompactList}\item Output\+Data\+Type const \& \textbf{ Output\+Parameter} () const \begin{DoxyCompactList}\small\item\em Get the output parameter. \end{DoxyCompactList}\item Output\+Data\+Type \& \textbf{ Output\+Parameter} () \begin{DoxyCompactList}\small\item\em Modify the output parameter. \end{DoxyCompactList}\item Output\+Data\+Type const \& \textbf{ Parameters} () const \begin{DoxyCompactList}\small\item\em Get the parameters. \end{DoxyCompactList}\item Output\+Data\+Type \& \textbf{ Parameters} () \begin{DoxyCompactList}\small\item\em Modify the parameters. \end{DoxyCompactList}\item {\footnotesize template$<$typename Archive $>$ }\\void \textbf{ serialize} (Archive \&ar, const unsigned int) \begin{DoxyCompactList}\small\item\em Serialize the layer. \end{DoxyCompactList}\item size\+\_\+t \textbf{ Vocab\+Size} () const \begin{DoxyCompactList}\small\item\em Get the size of the vocabulary. \end{DoxyCompactList}\end{DoxyCompactItemize} \subsection{Detailed Description} \subsubsection*{template$<$typename Input\+Data\+Type = arma\+::mat, typename Output\+Data\+Type = arma\+::mat$>$\newline class mlpack\+::ann\+::\+Lookup$<$ Input\+Data\+Type, Output\+Data\+Type $>$} The \doxyref{Lookup}{p.}{classmlpack_1_1ann_1_1Lookup} class stores word embeddings and retrieves them using tokens. The \doxyref{Lookup}{p.}{classmlpack_1_1ann_1_1Lookup} layer is always the first layer of the network. The input to the \doxyref{Lookup}{p.}{classmlpack_1_1ann_1_1Lookup} class is a matrix of shape (sequence\+Length, batch\+Size). The matrix consists of tokens which are used to lookup the table (i.\+e. weights) to find the embeddings of those tokens. The input shape \+: (sequence\+Length, batch\+Size). The output shape \+: (embedding\+Size, sequence\+Length, batch\+Size). \begin{DoxyTemplParams}{Template Parameters} {\em Input\+Data\+Type} & Type of the input data (arma\+::colvec, arma\+::mat, arma\+::sp\+\_\+mat or arma\+::cube). \\ \hline {\em Output\+Data\+Type} & Type of the output data (arma\+::colvec, arma\+::mat, arma\+::sp\+\_\+mat or arma\+::cube). \\ \hline \end{DoxyTemplParams} Definition at line 41 of file lookup.\+hpp. \subsection{Constructor \& Destructor Documentation} \mbox{\label{classmlpack_1_1ann_1_1Lookup_ad2a92a24a6c38f608d103d2ac2153a91}} \index{mlpack\+::ann\+::\+Lookup@{mlpack\+::ann\+::\+Lookup}!Lookup@{Lookup}} \index{Lookup@{Lookup}!mlpack\+::ann\+::\+Lookup@{mlpack\+::ann\+::\+Lookup}} \subsubsection{Lookup()} {\footnotesize\ttfamily \textbf{ Lookup} (\begin{DoxyParamCaption}\item[{const size\+\_\+t}]{vocab\+Size = {\ttfamily 0}, }\item[{const size\+\_\+t}]{embedding\+Size = {\ttfamily 0} }\end{DoxyParamCaption})} Create the \doxyref{Lookup}{p.}{classmlpack_1_1ann_1_1Lookup} object using the specified vocabulary and embedding size. \begin{DoxyParams}{Parameters} {\em vocab\+Size} & The size of the vocabulary. \\ \hline {\em embedding\+Size} & The length of each embedding vector. \\ \hline \end{DoxyParams} \subsection{Member Function Documentation} \mbox{\label{classmlpack_1_1ann_1_1Lookup_ad9ad1a3bdb0f3fff5c839ed155e4bbf8}} \index{mlpack\+::ann\+::\+Lookup@{mlpack\+::ann\+::\+Lookup}!Backward@{Backward}} \index{Backward@{Backward}!mlpack\+::ann\+::\+Lookup@{mlpack\+::ann\+::\+Lookup}} \subsubsection{Backward()} {\footnotesize\ttfamily void Backward (\begin{DoxyParamCaption}\item[{const arma\+::\+Mat$<$ eT $>$ \&}]{, }\item[{const arma\+::\+Mat$<$ eT $>$ \&}]{gy, }\item[{arma\+::\+Mat$<$ eT $>$ \&}]{g }\end{DoxyParamCaption})} Ordinary feed backward pass of a neural network, calculating the function f(x) by propagating x backwards trough f. Using the results from the feed forward pass. \begin{DoxyParams}{Parameters} {\em $\ast$} & (input) The propagated input activation. \\ \hline {\em gy} & The backpropagated error. \\ \hline {\em g} & The calculated gradient. \\ \hline \end{DoxyParams} \mbox{\label{classmlpack_1_1ann_1_1Lookup_a797f7edb44dd081e5e2b3cc316eef6bd}} \index{mlpack\+::ann\+::\+Lookup@{mlpack\+::ann\+::\+Lookup}!Delta@{Delta}} \index{Delta@{Delta}!mlpack\+::ann\+::\+Lookup@{mlpack\+::ann\+::\+Lookup}} \subsubsection{Delta()\hspace{0.1cm}{\footnotesize\ttfamily [1/2]}} {\footnotesize\ttfamily Output\+Data\+Type const\& Delta (\begin{DoxyParamCaption}{ }\end{DoxyParamCaption}) const\hspace{0.3cm}{\ttfamily [inline]}} Get the delta. Definition at line 99 of file lookup.\+hpp. \mbox{\label{classmlpack_1_1ann_1_1Lookup_ad6601342d560219ce951d554e69e5e87}} \index{mlpack\+::ann\+::\+Lookup@{mlpack\+::ann\+::\+Lookup}!Delta@{Delta}} \index{Delta@{Delta}!mlpack\+::ann\+::\+Lookup@{mlpack\+::ann\+::\+Lookup}} \subsubsection{Delta()\hspace{0.1cm}{\footnotesize\ttfamily [2/2]}} {\footnotesize\ttfamily Output\+Data\+Type\& Delta (\begin{DoxyParamCaption}{ }\end{DoxyParamCaption})\hspace{0.3cm}{\ttfamily [inline]}} Modify the delta. Definition at line 101 of file lookup.\+hpp. \mbox{\label{classmlpack_1_1ann_1_1Lookup_af901e8433309aa802f54ce6efdafe41b}} \index{mlpack\+::ann\+::\+Lookup@{mlpack\+::ann\+::\+Lookup}!Embedding\+Size@{Embedding\+Size}} \index{Embedding\+Size@{Embedding\+Size}!mlpack\+::ann\+::\+Lookup@{mlpack\+::ann\+::\+Lookup}} \subsubsection{Embedding\+Size()} {\footnotesize\ttfamily size\+\_\+t Embedding\+Size (\begin{DoxyParamCaption}{ }\end{DoxyParamCaption}) const\hspace{0.3cm}{\ttfamily [inline]}} Get the length of each embedding vector. Definition at line 112 of file lookup.\+hpp. References Lookup$<$ Input\+Data\+Type, Output\+Data\+Type $>$\+::serialize(). \mbox{\label{classmlpack_1_1ann_1_1Lookup_a461f849bc638c15bec262dc9c3a58abe}} \index{mlpack\+::ann\+::\+Lookup@{mlpack\+::ann\+::\+Lookup}!Forward@{Forward}} \index{Forward@{Forward}!mlpack\+::ann\+::\+Lookup@{mlpack\+::ann\+::\+Lookup}} \subsubsection{Forward()} {\footnotesize\ttfamily void Forward (\begin{DoxyParamCaption}\item[{const arma\+::\+Mat$<$ eT $>$ \&}]{input, }\item[{arma\+::\+Mat$<$ eT $>$ \&}]{output }\end{DoxyParamCaption})} Ordinary feed forward pass of a neural network, evaluating the function f(x) by propagating the activity forward through f. \begin{DoxyParams}{Parameters} {\em input} & Input data used for evaluating the specified function. \\ \hline {\em output} & Resulting output activation. \\ \hline \end{DoxyParams} \mbox{\label{classmlpack_1_1ann_1_1Lookup_aaf577db350e2130754490d8486fba215}} \index{mlpack\+::ann\+::\+Lookup@{mlpack\+::ann\+::\+Lookup}!Gradient@{Gradient}} \index{Gradient@{Gradient}!mlpack\+::ann\+::\+Lookup@{mlpack\+::ann\+::\+Lookup}} \subsubsection{Gradient()\hspace{0.1cm}{\footnotesize\ttfamily [1/3]}} {\footnotesize\ttfamily void Gradient (\begin{DoxyParamCaption}\item[{const arma\+::\+Mat$<$ eT $>$ \&}]{input, }\item[{const arma\+::\+Mat$<$ eT $>$ \&}]{error, }\item[{arma\+::\+Mat$<$ eT $>$ \&}]{gradient }\end{DoxyParamCaption})} Calculate the gradient using the output delta and the input activation. \begin{DoxyParams}{Parameters} {\em input} & The input parameter used for calculating the gradient. \\ \hline {\em error} & The calculated error. \\ \hline {\em gradient} & The calculated gradient. \\ \hline \end{DoxyParams} \mbox{\label{classmlpack_1_1ann_1_1Lookup_a0f1f4e6d93472d83852731a96c8c3f59}} \index{mlpack\+::ann\+::\+Lookup@{mlpack\+::ann\+::\+Lookup}!Gradient@{Gradient}} \index{Gradient@{Gradient}!mlpack\+::ann\+::\+Lookup@{mlpack\+::ann\+::\+Lookup}} \subsubsection{Gradient()\hspace{0.1cm}{\footnotesize\ttfamily [2/3]}} {\footnotesize\ttfamily Output\+Data\+Type const\& Gradient (\begin{DoxyParamCaption}{ }\end{DoxyParamCaption}) const\hspace{0.3cm}{\ttfamily [inline]}} Get the gradient. Definition at line 104 of file lookup.\+hpp. \mbox{\label{classmlpack_1_1ann_1_1Lookup_a19abce4739c3b0b658b612537e21956a}} \index{mlpack\+::ann\+::\+Lookup@{mlpack\+::ann\+::\+Lookup}!Gradient@{Gradient}} \index{Gradient@{Gradient}!mlpack\+::ann\+::\+Lookup@{mlpack\+::ann\+::\+Lookup}} \subsubsection{Gradient()\hspace{0.1cm}{\footnotesize\ttfamily [3/3]}} {\footnotesize\ttfamily Output\+Data\+Type\& Gradient (\begin{DoxyParamCaption}{ }\end{DoxyParamCaption})\hspace{0.3cm}{\ttfamily [inline]}} Modify the gradient. Definition at line 106 of file lookup.\+hpp. \mbox{\label{classmlpack_1_1ann_1_1Lookup_a0ee21c2a36e5abad1e7a9d5dd00849f9}} \index{mlpack\+::ann\+::\+Lookup@{mlpack\+::ann\+::\+Lookup}!Output\+Parameter@{Output\+Parameter}} \index{Output\+Parameter@{Output\+Parameter}!mlpack\+::ann\+::\+Lookup@{mlpack\+::ann\+::\+Lookup}} \subsubsection{Output\+Parameter()\hspace{0.1cm}{\footnotesize\ttfamily [1/2]}} {\footnotesize\ttfamily Output\+Data\+Type const\& Output\+Parameter (\begin{DoxyParamCaption}{ }\end{DoxyParamCaption}) const\hspace{0.3cm}{\ttfamily [inline]}} Get the output parameter. Definition at line 94 of file lookup.\+hpp. \mbox{\label{classmlpack_1_1ann_1_1Lookup_a21d5f745f02c709625a4ee0907f004a5}} \index{mlpack\+::ann\+::\+Lookup@{mlpack\+::ann\+::\+Lookup}!Output\+Parameter@{Output\+Parameter}} \index{Output\+Parameter@{Output\+Parameter}!mlpack\+::ann\+::\+Lookup@{mlpack\+::ann\+::\+Lookup}} \subsubsection{Output\+Parameter()\hspace{0.1cm}{\footnotesize\ttfamily [2/2]}} {\footnotesize\ttfamily Output\+Data\+Type\& Output\+Parameter (\begin{DoxyParamCaption}{ }\end{DoxyParamCaption})\hspace{0.3cm}{\ttfamily [inline]}} Modify the output parameter. Definition at line 96 of file lookup.\+hpp. \mbox{\label{classmlpack_1_1ann_1_1Lookup_aa530552c7ef915c952fbacc77b965c90}} \index{mlpack\+::ann\+::\+Lookup@{mlpack\+::ann\+::\+Lookup}!Parameters@{Parameters}} \index{Parameters@{Parameters}!mlpack\+::ann\+::\+Lookup@{mlpack\+::ann\+::\+Lookup}} \subsubsection{Parameters()\hspace{0.1cm}{\footnotesize\ttfamily [1/2]}} {\footnotesize\ttfamily Output\+Data\+Type const\& Parameters (\begin{DoxyParamCaption}{ }\end{DoxyParamCaption}) const\hspace{0.3cm}{\ttfamily [inline]}} Get the parameters. Definition at line 89 of file lookup.\+hpp. \mbox{\label{classmlpack_1_1ann_1_1Lookup_a9c5c5900772a689d5a6b59778ec67120}} \index{mlpack\+::ann\+::\+Lookup@{mlpack\+::ann\+::\+Lookup}!Parameters@{Parameters}} \index{Parameters@{Parameters}!mlpack\+::ann\+::\+Lookup@{mlpack\+::ann\+::\+Lookup}} \subsubsection{Parameters()\hspace{0.1cm}{\footnotesize\ttfamily [2/2]}} {\footnotesize\ttfamily Output\+Data\+Type\& Parameters (\begin{DoxyParamCaption}{ }\end{DoxyParamCaption})\hspace{0.3cm}{\ttfamily [inline]}} Modify the parameters. Definition at line 91 of file lookup.\+hpp. \mbox{\label{classmlpack_1_1ann_1_1Lookup_af0dd9205158ccf7bcfcd8ff81f79c927}} \index{mlpack\+::ann\+::\+Lookup@{mlpack\+::ann\+::\+Lookup}!serialize@{serialize}} \index{serialize@{serialize}!mlpack\+::ann\+::\+Lookup@{mlpack\+::ann\+::\+Lookup}} \subsubsection{serialize()} {\footnotesize\ttfamily void serialize (\begin{DoxyParamCaption}\item[{Archive \&}]{ar, }\item[{const unsigned}]{int }\end{DoxyParamCaption})} Serialize the layer. Referenced by Lookup$<$ Input\+Data\+Type, Output\+Data\+Type $>$\+::\+Embedding\+Size(). \mbox{\label{classmlpack_1_1ann_1_1Lookup_acc5c821b1d52424abca736bd81c3f476}} \index{mlpack\+::ann\+::\+Lookup@{mlpack\+::ann\+::\+Lookup}!Vocab\+Size@{Vocab\+Size}} \index{Vocab\+Size@{Vocab\+Size}!mlpack\+::ann\+::\+Lookup@{mlpack\+::ann\+::\+Lookup}} \subsubsection{Vocab\+Size()} {\footnotesize\ttfamily size\+\_\+t Vocab\+Size (\begin{DoxyParamCaption}{ }\end{DoxyParamCaption}) const\hspace{0.3cm}{\ttfamily [inline]}} Get the size of the vocabulary. Definition at line 109 of file lookup.\+hpp. The documentation for this class was generated from the following file\+:\begin{DoxyCompactItemize} \item /var/www/mlpack.\+ratml.\+org/mlpack.\+org/\+\_\+src/mlpack-\/git/src/mlpack/methods/ann/layer/\textbf{ lookup.\+hpp}\end{DoxyCompactItemize}