Mercurial > hg > cip2012
comparison draft.tex @ 24:79ede31feb20
Stuffed a load more figures in.
author | samer |
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date | Tue, 13 Mar 2012 11:28:02 +0000 |
parents | f9a67e19a66b |
children | 3f08d18c65ce |
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13 \usetikzlibrary{matrix} | 13 \usetikzlibrary{matrix} |
14 \usetikzlibrary{patterns} | 14 \usetikzlibrary{patterns} |
15 \usetikzlibrary{arrows} | 15 \usetikzlibrary{arrows} |
16 | 16 |
17 \let\citep=\cite | 17 \let\citep=\cite |
18 \newcommand{\colfig}[2][1]{\includegraphics[width=#1\linewidth]{figs/#2}}% | 18 \newcommand{\colfig}[2][1]{\includegraphics[width=#1\linewidth]{ifigs/#2}}% |
19 \newcommand\preals{\reals_+} | 19 \newcommand\preals{\reals_+} |
20 \newcommand\X{\mathcal{X}} | 20 \newcommand\X{\mathcal{X}} |
21 \newcommand\Y{\mathcal{Y}} | 21 \newcommand\Y{\mathcal{Y}} |
22 \newcommand\domS{\mathcal{S}} | 22 \newcommand\domS{\mathcal{S}} |
23 \newcommand\A{\mathcal{A}} | 23 \newcommand\A{\mathcal{A}} |
108 degrees of belief about the various proposition which may or may not | 108 degrees of belief about the various proposition which may or may not |
109 hold, and, as has been argued elsewhere \cite{Cox1946,Jaynes27}, best | 109 hold, and, as has been argued elsewhere \cite{Cox1946,Jaynes27}, best |
110 quantified in terms of Bayesian probability theory. | 110 quantified in terms of Bayesian probability theory. |
111 Thus, we suppose that | 111 Thus, we suppose that |
112 when we listen to music, expectations are created on the basis of our | 112 when we listen to music, expectations are created on the basis of our |
113 familiarity with various stylistic norms %, that is, using models that | 113 familiarity with various stylistic norms that apply to music in general, |
114 encode the statistics of music in general, the particular styles of | 114 the particular style (or styles) of music that seem best to fit the piece |
115 music that seem best to fit the piece we happen to be listening to, and | 115 we are listening to, and |
116 the emerging structures peculiar to the current piece. There is | 116 the emerging structures peculiar to the current piece. There is |
117 experimental evidence that human listeners are able to internalise | 117 experimental evidence that human listeners are able to internalise |
118 statistical knowledge about musical structure, \eg | 118 statistical knowledge about musical structure, \eg |
119 \citep{SaffranJohnsonAslin1999,EerolaToiviainenKrumhansl2002}, and also | 119 \citep{SaffranJohnsonAslin1999,EerolaToiviainenKrumhansl2002}, and also |
120 that statistical models can form an effective basis for computational | 120 that statistical models can form an effective basis for computational |
121 analysis of music, \eg | 121 analysis of music, \eg |
122 \cite{ConklinWitten95,PonsfordWigginsMellish1999,Pearce2005}. | 122 \cite{ConklinWitten95,PonsfordWigginsMellish1999,Pearce2005}. |
123 | 123 |
124 \subsection{Music and information theory} | 124 \subsection{Music and information theory} |
125 Given a probabilistic framework for music modelling and prediction, | 125 With a probabilistic framework for music modelling and prediction in hand, |
126 it is a small step to apply quantitative information theory \cite{Shannon48} to | 126 we are in a position to apply quantitative information theory \cite{Shannon48}. |
127 the models at hand. | |
128 The relationship between information theory and music and art in general has been the | 127 The relationship between information theory and music and art in general has been the |
129 subject of some interest since the 1950s | 128 subject of some interest since the 1950s |
130 \cite{Youngblood58,CoonsKraehenbuehl1958,HillerBean66,Moles66,Meyer67,Cohen1962}. | 129 \cite{Youngblood58,CoonsKraehenbuehl1958,HillerBean66,Moles66,Meyer67,Cohen1962}. |
131 The general thesis is that perceptible qualities and subjective | 130 The general thesis is that perceptible qualities and subjective |
132 states like uncertainty, surprise, complexity, tension, and interestingness | 131 states like uncertainty, surprise, complexity, tension, and interestingness |
154 with `low entropy'. These values were determined from some known `objective' | 153 with `low entropy'. These values were determined from some known `objective' |
155 probability model of the stimuli,% | 154 probability model of the stimuli,% |
156 \footnote{% | 155 \footnote{% |
157 The notion of objective probabalities and whether or not they can | 156 The notion of objective probabalities and whether or not they can |
158 usefully be said to exist is the subject of some debate, with advocates of | 157 usefully be said to exist is the subject of some debate, with advocates of |
159 subjective probabilities including de Finetti \cite{deFinetti}. | 158 subjective probabilities including de Finetti \cite{deFinetti}.} |
160 Accordingly, we will treat the concept of a `true' or `objective' probability | |
161 models with a grain of salt and not rely on them in our | |
162 theoretical development.}% | |
163 or from simple statistical analyses such as | 159 or from simple statistical analyses such as |
164 computing emprical distributions. Our approach is explicitly to consider the role | 160 computing emprical distributions. Our approach is explicitly to consider the role |
165 of the observer in perception, and more specifically, to consider estimates of | 161 of the observer in perception, and more specifically, to consider estimates of |
166 entropy \etc with respect to \emph{subjective} probabilities. | 162 entropy \etc with respect to \emph{subjective} probabilities. |
167 \subsection{Information dynamic approach} | 163 \subsection{Information dynamic approach} |
168 | 164 |
169 Bringing the various strands together, our working hypothesis is that | 165 Bringing the various strands together, our working hypothesis is that as a |
170 as a listener (to which will refer gender neutrally as `it') | 166 listener (to which will refer as `it') listens to a piece of music, it maintains |
171 listens to a piece of music, it maintains a dynamically evolving statistical | 167 a dynamically evolving statistical model that enables it to make predictions |
172 model that enables it to make predictions about how the piece will | 168 about how the piece will continue, relying on both its previous experience |
173 continue, relying on both its previous experience of music and the immediate | 169 of music and the immediate context of the piece. As events unfold, it revises |
174 context of the piece. | 170 its model and hence its probabilistic belief state, which includes predictive |
175 As events unfold, it revises its model and hence its probabilistic belief state, | 171 distributions over future observations. These distributions and changes in |
176 which includes predictive distributions over future observations. | 172 distributions can be characterised in terms of a handful of information |
177 These distributions and changes in distributions can be characterised in terms of a handful of information | 173 theoretic-measures such as entropy and relative entropy. By tracing the |
178 theoretic-measures such as entropy and relative entropy. | 174 evolution of a these measures, we obtain a representation which captures much |
179 % to measure uncertainty and information. %, that is, changes in predictive distributions maintained by the model. | 175 of the significant structure of the music, but does so at a high level of |
180 By tracing the evolution of a these measures, we obtain a representation | 176 \emph{abstraction}, since it is sensitive mainly to \emph{patterns} of occurence, |
181 which captures much of the significant structure of the | 177 rather the details of which specific things occur or even the sensory modality |
182 music. | 178 through which they are detected. This suggests that the |
183 This approach has a number of features which we list below. | |
184 | |
185 \emph{Abstraction}: | |
186 Because it is sensitive mainly to \emph{patterns} of occurence, | |
187 rather the details of which specific things occur, | |
188 it operates at a level of abstraction removed from the details of the sensory | |
189 experience and the medium through which it was received, suggesting that the | |
190 same approach could, in principle, be used to analyse and compare information | 179 same approach could, in principle, be used to analyse and compare information |
191 flow in different temporal media regardless of whether they are auditory, | 180 flow in different temporal media regardless of whether they are auditory, |
192 visual or otherwise. | 181 visual or otherwise. |
193 | 182 |
194 \emph{Generality} applicable to any probabilistic model. | 183 In addition, the information dynamic approach gives us a principled way |
195 | 184 to address the notion of \emph{subjectivity}, since the analysis is dependent on the |
196 \emph{Subjectivity}: | 185 probability model the observer starts off with, which may depend on prior experience |
197 Since the analysis is dependent on the probability model the observer brings to the | 186 or other factors, and which may change over time. Thus, inter-subject variablity and |
198 problem, which may depend on prior experience or other factors, and which may change | 187 variation in subjects' responses over time are |
199 over time, inter-subject variablity and variation in subjects' responses over time are | 188 fundamental to the theory. |
200 fundamental to the theory. It is essentially a theory of subjective response | |
201 | 189 |
202 %modelling the creative process, which often alternates between generative | 190 %modelling the creative process, which often alternates between generative |
203 %and selective or evaluative phases \cite{Boden1990}, and would have | 191 %and selective or evaluative phases \cite{Boden1990}, and would have |
204 %applications in tools for computer aided composition. | 192 %applications in tools for computer aided composition. |
205 | 193 |
206 | 194 |
207 \section{Theoretical review} | 195 \section{Theoretical review} |
208 | 196 |
197 \subsection{Entropy and information in sequences} | |
209 In this section, we summarise the definitions of some of the relevant quantities | 198 In this section, we summarise the definitions of some of the relevant quantities |
210 in information dynamics and show how they can be computed in some simple probabilistic | 199 in information dynamics and show how they can be computed in some simple probabilistic |
211 models (namely, first and higher-order Markov chains, and Gaussian processes [Peter?]). | 200 models (namely, first and higher-order Markov chains, and Gaussian processes [Peter?]). |
212 | 201 |
213 \begin{fig}{venn-example} | 202 \begin{fig}{venn-example} |
278 I_{12|3} + I_{123} &= I(X_1;X_2) | 267 I_{12|3} + I_{123} &= I(X_1;X_2) |
279 \end{align*} | 268 \end{align*} |
280 } | 269 } |
281 \end{tabular} | 270 \end{tabular} |
282 \caption{ | 271 \caption{ |
283 Venn diagram visualisation of entropies and mutual informations | 272 Information diagram visualisation of entropies and mutual informations |
284 for three random variables $X_1$, $X_2$ and $X_3$. The areas of | 273 for three random variables $X_1$, $X_2$ and $X_3$. The areas of |
285 the three circles represent $H(X_1)$, $H(X_2)$ and $H(X_3)$ respectively. | 274 the three circles represent $H(X_1)$, $H(X_2)$ and $H(X_3)$ respectively. |
286 The total shaded area is the joint entropy $H(X_1,X_2,X_3)$. | 275 The total shaded area is the joint entropy $H(X_1,X_2,X_3)$. |
287 The central area $I_{123}$ is the co-information \cite{McGill1954}. | 276 The central area $I_{123}$ is the co-information \cite{McGill1954}. |
288 Some other information measures are indicated in the legend. | 277 Some other information measures are indicated in the legend. |
429 the entropy rate and the erasure entropy rate: $b_\mu = h_\mu - r_\mu$. | 418 the entropy rate and the erasure entropy rate: $b_\mu = h_\mu - r_\mu$. |
430 These relationships are illustrated in \Figrf{predinfo-bg}, along with | 419 These relationships are illustrated in \Figrf{predinfo-bg}, along with |
431 several of the information measures we have discussed so far. | 420 several of the information measures we have discussed so far. |
432 | 421 |
433 | 422 |
423 \begin{fig}{wundt} | |
424 \raisebox{-4em}{\colfig[0.43]{wundt}} | |
425 % {\ \shortstack{{\Large$\longrightarrow$}\\ {\scriptsize\emph{exposure}}}\ } | |
426 {\ {\large$\longrightarrow$}\ } | |
427 \raisebox{-4em}{\colfig[0.43]{wundt2}} | |
428 \caption{ | |
429 The Wundt curve relating randomness/complexity with | |
430 perceived value. Repeated exposure sometimes results | |
431 in a move to the left along the curve \cite{Berlyne71}. | |
432 } | |
433 \end{fig} | |
434 | |
435 | |
434 \subsection{First order Markov chains} | 436 \subsection{First order Markov chains} |
435 These are the simplest non-trivial models to which information dynamics methods | 437 These are the simplest non-trivial models to which information dynamics methods |
436 can be applied. In \cite{AbdallahPlumbley2009} we, showed that the predictive information | 438 can be applied. In \cite{AbdallahPlumbley2009} we, showed that the predictive information |
437 rate can be expressed simply in terms of the entropy rate of the Markov chain. | 439 rate can be expressed simply in terms of the entropy rate of the Markov chain. |
438 If we let $a$ denote the transition matrix of the Markov chain, and $h_a$ it's | 440 If we let $a$ denote the transition matrix of the Markov chain, and $h_a$ it's |
462 \section{Information Dynamics in Analysis} | 464 \section{Information Dynamics in Analysis} |
463 | 465 |
464 \subsection{Musicological Analysis} | 466 \subsection{Musicological Analysis} |
465 refer to the work with the analysis of minimalist pieces | 467 refer to the work with the analysis of minimalist pieces |
466 | 468 |
469 \begin{fig}{twopages} | |
470 % \colfig[0.96]{matbase/fig9471} % update from mbc paper | |
471 \colfig[0.97]{matbase/fig72663}\\ % later update from mbc paper (Keith's new picks) | |
472 \vspace*{1em} | |
473 \colfig[0.97]{matbase/fig13377} % rule based analysis | |
474 \caption{Analysis of \emph{Two Pages}. | |
475 The thick vertical lines are the part boundaries as indicated in | |
476 the score by the composer. | |
477 The thin grey lines | |
478 indicate changes in the melodic `figures' of which the piece is | |
479 constructed. In the `model information rate' panel, the black asterisks | |
480 mark the | |
481 six most surprising moments selected by Keith Potter. | |
482 The bottom panel shows a rule-based boundary strength analysis computed | |
483 using Cambouropoulos' LBDM. | |
484 All information measures are in nats and time is in notes. | |
485 } | |
486 \end{fig} | |
487 | |
488 \begin{fig}{metre} | |
489 \scalebox{1}[0.8]{% | |
490 \begin{tabular}{cc} | |
491 \colfig[0.45]{matbase/fig36859} & \colfig[0.45]{matbase/fig88658} \\ | |
492 \colfig[0.45]{matbase/fig48061} & \colfig[0.45]{matbase/fig46367} \\ | |
493 \colfig[0.45]{matbase/fig99042} & \colfig[0.45]{matbase/fig87490} | |
494 % \colfig[0.46]{matbase/fig56807} & \colfig[0.48]{matbase/fig27144} \\ | |
495 % \colfig[0.46]{matbase/fig87574} & \colfig[0.48]{matbase/fig13651} \\ | |
496 % \colfig[0.44]{matbase/fig19913} & \colfig[0.46]{matbase/fig66144} \\ | |
497 % \colfig[0.48]{matbase/fig73098} & \colfig[0.48]{matbase/fig57141} \\ | |
498 % \colfig[0.48]{matbase/fig25703} & \colfig[0.48]{matbase/fig72080} \\ | |
499 % \colfig[0.48]{matbase/fig9142} & \colfig[0.48]{matbase/fig27751} | |
500 | |
501 \end{tabular}% | |
502 } | |
503 \caption{Metrical analysis by computing average surprisingness and | |
504 informative of notes at different periodicities (\ie hypothetical | |
505 bar lengths) and phases (\ie positions within a bar). | |
506 } | |
507 \end{fig} | |
508 | |
467 \subsection{Content analysis/Sound Categorisation}. | 509 \subsection{Content analysis/Sound Categorisation}. |
468 Using Information Dynamics it is possible to segment music. From there we | 510 Using Information Dynamics it is possible to segment music. From there we |
469 can then use this to search large data sets. Determine musical structure for | 511 can then use this to search large data sets. Determine musical structure for |
470 the purpose of playlist navigation and search. | 512 the purpose of playlist navigation and search. |
471 \emph{Peter} | 513 \emph{Peter} |
472 | 514 |
473 \subsection{Beat Tracking} | 515 \subsection{Beat Tracking} |
474 \emph{Andrew} | 516 \emph{Andrew} |
475 | 517 |
476 | 518 |
477 \section{Information Dynamics as Design Tool} | 519 \section{Information dynamics as compositional aid} |
478 | 520 |
479 In addition to applying information dynamics to analysis, it is also possible | 521 In addition to applying information dynamics to analysis, it is also possible |
480 use this approach in design, such as the composition of musical materials. By | 522 use this approach in design, such as the composition of musical materials. By |
481 providing a framework for linking information theoretic measures to the control | 523 providing a framework for linking information theoretic measures to the control |
482 of generative processes, it becomes possible to steer the output of these processes | 524 of generative processes, it becomes possible to steer the output of these processes |
539 triangle, the corresponding transition matrix is returned. Figure \ref{TheTriangle} | 581 triangle, the corresponding transition matrix is returned. Figure \ref{TheTriangle} |
540 shows how the triangle maps to different measures of redundancy, entropy rate | 582 shows how the triangle maps to different measures of redundancy, entropy rate |
541 and predictive information rate.\emph{self-plagiarised} | 583 and predictive information rate.\emph{self-plagiarised} |
542 \begin{figure} | 584 \begin{figure} |
543 \centering | 585 \centering |
544 \includegraphics[width=\linewidth]{figs/TheTriangle.pdf} | 586 \includegraphics[width=0.85\linewidth]{figs/TheTriangle.pdf} |
545 \caption{The Melody Triangle\label{TheTriangle}} | 587 \caption{The Melody Triangle\label{TheTriangle}} |
546 \end{figure} | 588 \end{figure} |
547 Each corner corresponds to three different extremes of predictability and | 589 Each corner corresponds to three different extremes of predictability and |
548 unpredictability, which could be loosely characterised as `periodicity', `noise' | 590 unpredictability, which could be loosely characterised as `periodicity', `noise' |
549 and `repetition'. Melodies from the `noise' corner have no discernible pattern; | 591 and `repetition'. Melodies from the `noise' corner have no discernible pattern; |