fixed some index entries
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@ -6,8 +6,9 @@
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A common problem in statistics is to estimate from a probability
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distribution one or more parameters $\theta$ that best describe the
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data $x_1, x_2, \ldots x_n$. \enterm{Maximum likelihood estimators}
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(\enterm[mle|see{Maximum likelihood estimators}]{mle},
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data $x_1, x_2, \ldots x_n$. \enterm[maximum likelihood
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estimator]{Maximum likelihood estimators} (\enterm[mle|see{maximum
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likelihood estimator}]{mle},
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\determ{Maximum-Likelihood-Sch\"atzer}) choose the parameters such
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that they maximize the likelihood of the data $x_1, x_2, \ldots x_n$
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to originate from the distribution.
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@ -228,7 +229,7 @@ maximized respectively.
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\begin{figure}[t]
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\includegraphics[width=1\textwidth]{mlepropline}
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\titlecaption{\label{mleproplinefig} Maximum likelihood estimation
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of the slope of line through the origin.}{The data (blue and
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of the slope of a line through the origin.}{The data (blue and
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left histogram) originate from a straight line $y=mx$ trough the origin
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(red). The maximum-likelihood estimation of the slope $m$ of the
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regression line (orange), \eqnref{mleslope}, is close to the true
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@ -257,6 +258,7 @@ respect to $\theta$ and equate it to zero:
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This is an analytical expression for the estimation of the slope
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$\theta$ of the regression line (\figref{mleproplinefig}).
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\subsection{Linear and non-linear fits}
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A gradient descent, as we have done in the previous chapter, is not
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necessary for fitting the slope of a straight line, because the slope
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can be directly computed via \eqnref{mleslope}. More generally, this
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@ -275,6 +277,7 @@ exponential decay
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Such cases require numerical solutions for the optimization of the
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cost function, e.g. the gradient descent \matlabfun{lsqcurvefit()}.
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\subsection{Relation between slope and correlation coefficient}
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Let us have a closer look on \eqnref{mleslope}. If the standard
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deviation of the data $\sigma_i$ is the same for each data point,
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i.e. $\sigma_i = \sigma_j \; \forall \; i, j$, the standard deviation drops
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@ -93,7 +93,7 @@ number of datasets.
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\subsection{Simple plotting}
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Creating a simple line-plot is rather easy. Assuming there exists a
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variable \varcode{y} in the \codeterm{Workspace} that contains the
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variable \varcode{y} in the \codeterm{workspace} that contains the
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measurement data it is enough to call \code[plot()]{plot(y)}. At the
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first call of this function a new \codeterm{figure} will be opened and
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the data will be plotted with as a line plot. If you repeatedly call
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@ -3,7 +3,7 @@
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\chapter{Spiketrain analysis}
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\exercisechapter{Spiketrain analysis}
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\enterm[Action potentials]{action potentials} (\enterm{spikes}) are
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\enterm[action potential]{Action potentials} (\enterm{spikes}) are
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the carriers of information in the nervous system. Thereby it is the
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time at which the spikes are generated that is of importance for
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information transmission. The waveform of the action potential is
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@ -110,9 +110,9 @@ describing the statistics of stochastic real-valued variables:
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\frac{1}{n}\sum\limits_{i=1}^n T_i$.
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\item Standard deviation of the interspike intervals: $\sigma_{ISI} = \sqrt{\langle (T - \langle T
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\rangle)^2 \rangle}$\vspace{1ex}
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\item \enterm{Coefficient of variation}: $CV_{ISI} =
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\item \enterm[coefficient of variation]{Coefficient of variation}: $CV_{ISI} =
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\frac{\sigma_{ISI}}{\mu_{ISI}}$.
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\item \enterm{Diffusion coefficient}: $D_{ISI} =
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\item \enterm[diffusion coefficient]{Diffusion coefficient}: $D_{ISI} =
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\frac{\sigma_{ISI}^2}{2\mu_{ISI}^3}$.
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\end{itemize}
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@ -356,7 +356,7 @@ should take care when defining nested functions.
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\section{Specifics when using scripts}
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A similar problem as with nested function arises when using scripts
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(instead of functions). All variables that are defined within a script
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become available in the global \codeterm{Workspace}. There is the risk
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become available in the global \codeterm{workspace}. There is the risk
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of name conflicts, that is, a called sub-script redefines or uses the
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same variable name and may \emph{silently} change its content. The
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user will not be notified about this change and the calling script may
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@ -76,8 +76,8 @@ large deviations.
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\begin{exercise}{meanSquareError.m}{}\label{mseexercise}%
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Implement a function \code{meanSquareError()}, that calculates the
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\emph{mean square distance} bewteen a vector of observations ($y$)
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and respective predictions ($y^{est}$). \pagebreak[4]
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\emph{mean square distance} between a vector of observations ($y$)
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and respective predictions ($y^{est}$).
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\end{exercise}
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@ -147,11 +147,11 @@ data are smaller than the 3$^{\rm rd}$ quartile.
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% from a normal distribution.}
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% \end{figure}
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\enterm{Box-whisker plots} are commonly used to visualize and compare
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the distribution of unimodal data. A box is drawn around the median
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that extends from the 1$^{\rm st}$ to the 3$^{\rm rd}$ quartile. The
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whiskers mark the minimum and maximum value of the data set
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(\figref{displayunivariatedatafig} (3)).
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\enterm[box-whisker plots]{Box-whisker plots} are commonly used to
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visualize and compare the distribution of unimodal data. A box is
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drawn around the median that extends from the 1$^{\rm st}$ to the
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3$^{\rm rd}$ quartile. The whiskers mark the minimum and maximum value
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of the data set (\figref{displayunivariatedatafig} (3)).
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\begin{exercise}{univariatedata.m}{}
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Generate 40 normally distributed random numbers with a mean of 2 and
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@ -175,7 +175,7 @@ The distribution of values in a data set is estimated by histograms
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\subsection{Histograms}
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\enterm[Histogram]{Histograms} count the frequency $n_i$ of
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\enterm[histogram]{Histograms} count the frequency $n_i$ of
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$N=\sum_{i=1}^M n_i$ measurements in each of $M$ bins $i$
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(\figref{diehistogramsfig} left). The bins tile the data range
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usually into intervals of the same size. The width of the bins is
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@ -193,8 +193,9 @@ categories $i$ is the \enterm{histogram}, or the \enterm{frequency
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with the expected theoretical distribution of $P=1/6$.}
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\end{figure}
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Histograms are often used to estimate the \enterm{probability
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distribution} of the data values.
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Histograms are often used to estimate the
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\enterm[probability!distribution]{probability distribution} of the
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data values.
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\subsection{Probabilities}
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In the frequentist interpretation of probability, the probability of
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@ -253,13 +254,14 @@ probability can also be expressed as $P(x_0<x<x_0 + \Delta x)$.
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In the limit to very small ranges $\Delta x$ the probability of
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getting a measurement between $x_0$ and $x_0+\Delta x$ scales down to
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zero with $\Delta x$:
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\[ P(x_0<x<x_0+\Delta x) \approx p(x_0) \cdot \Delta x \; . \]
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In here the quantity $p(x_00)$ is a so called \enterm{probability
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density} that is larger than zero and that describes the
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distribution of the data values. The probability density is not a
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unitless probability with values between 0 and 1, but a number that
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takes on any positive real number and has as a unit the inverse of the
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unit of the data values --- hence the name ``density''.
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\[ P(x_0<x<x_0+\Delta x) \approx p(x_0) \cdot \Delta x \; . \]
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In here the quantity $p(x_00)$ is a so called
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\enterm[probability!density]{probability density} that is larger than
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zero and that describes the distribution of the data values. The
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probability density is not a unitless probability with values between
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0 and 1, but a number that takes on any positive real number and has
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as a unit the inverse of the unit of the data values --- hence the
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name ``density''.
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\begin{figure}[t]
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\includegraphics[width=1\textwidth]{pdfprobabilities}
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@ -280,14 +282,14 @@ the probability density over the whole real axis must be one:
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\end{equation}
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The function $p(x)$, that assigns to every $x$ a probability density,
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is called \enterm{probability density function},
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is called \enterm[probability!density function]{probability density function},
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\enterm[pdf|see{probability density function}]{pdf}, or just
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\enterm[density|see{probability density function}]{density}
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(\determ{Wahrscheinlichkeitsdichtefunktion}). The well known
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\enterm{normal distribution} (\determ{Normalverteilung}) is an example of a
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probability density function
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\[ p_g(x) = \frac{1}{\sqrt{2\pi\sigma^2}}e^{-\frac{(x-\mu)^2}{2\sigma^2}} \]
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--- the \enterm{Guassian distribution}
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--- the \enterm{Gaussian distribution}
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(\determ{Gau{\ss}sche-Glockenkurve}) with mean $\mu$ and standard
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deviation $\sigma$.
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The factor in front of the exponential function ensures the normalization to
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