@@ -3532,8 +3532,8 @@ \subsection{Exercise 12}
35323532\begin {frame }{Ex12: Binary Classification}
35333533Objectives
35343534\begin {itemize }
3535- \item binary classifier as most simple non-linear model
3536- \item check ingredients on that model: architecture, output activation function, an appropriate loss function, forward and back propagation, gradient descent
3535+ \item binary classifier as most simple non-linear model using sigmoid activation function
3536+ \item check ingredients on that model: architecture, output activation function, an appropriate loss function (sigmoid) , forward and back propagation, gradient descent
35373537\end {itemize }
35383538\end {frame }
35393539
@@ -3972,7 +3972,7 @@ \subsection{Exercise 13}
39723972\end {itemize }
39733973\end {frame }
39743974
3975- \begin {frame }{Binary Classification with Hidden Layer Model}
3975+ \begin {frame }{Binary Classification with Hidden Layers and Sigmoid Output Model}
39763976%
39773977\vspace {-0.25cm}
39783978\begin {center }
@@ -4121,8 +4121,89 @@ \subsection{Exercise 13}
41214121
41224122
41234123
4124+ \begin {frame }[t]{Confusion Matrix for Binary Classification}
4125+ %
4126+ \begin {center }
4127+ \begin {tikzpicture }[scale=1.25]
4128+ \tikzstyle {mtxi}=[draw, shape=rectangle,minimum size=1.5cm]
4129+ \tikzstyle {mtxo}=[draw=none, shape=rectangle,minimum size=0.5cm]
4130+ \node [mtxi, fill=C2!75, align=center](tn) at (-0.75,+0.75){$ \textcolor {C0}{0} | \textcolor {C3}{0}$ \\ TN\\ \textcolor {C3}{0},\textcolor {C0}{0}};
4131+ \node [mtxi, align=center](fp) at (+0.75,+0.75){$ \textcolor {C0}{1} | \textcolor {C3}{0}$ \\ FP\\ \textcolor {C3}{0},\textcolor {C0}{1}};
4132+ \node [mtxi, align=center](fn) at (-0.75,-0.75){$ \textcolor {C0}{0} | \textcolor {C3}{1}$ \\ FN\\ \textcolor {C3}{1},\textcolor {C0}{0}};
4133+ \node [mtxi, fill=C2!75, align=center](tp) at (+0.75,-0.75){$ \textcolor {C0}{1} | \textcolor {C3}{1}$ \\ TP\\ \textcolor {C3}{1},\textcolor {C0}{1}};
4134+ %
4135+ \node [mtxo, align=center](realtrue) at (-1.5,+0.75){$ \textcolor {C3}{0}$ };
4136+ \node [mtxo, align=center](realfalse) at (-1.5,-0.75){$ \textcolor {C3}{1}$ };
4137+ \node [mtxo, align=center](predtrue) at (-0.75,+1.5){$ \textcolor {C0}{0}$ };
4138+ \node [mtxo, align=center](predfalse) at (+0.75,1.5){$ \textcolor {C0}{1}$ };
4139+ %
4140+ \node [mtxo, align=center, rotate=90](reallbl) at (-1.75,0){\textcolor {C3}{real} class};
4141+ \node [mtxo, align=center](predlbl) at (0,1.75){\textcolor {C0}{predicted} class};
4142+ %
4143+ \node [mtxo, align=left](realfalse) at (2.25,+0.75){$ \text {R}_0 = \text {TN}+\text {FP}$ };
4144+ \node [mtxo, align=left](realtrue) at (2.25,-0.75){$ \text {R}_1 = \text {FN}+\text {TP}$ };
4145+ %
4146+ \node [mtxo, align=center](predfalse) at (-0.75,-1.75){$ \text {P}_0 =$ \\ $ \text {TN}+\text {FN}$ };
4147+ \node [mtxo, align=center](predtrue) at (+0.75,-1.75){$ \text {P}_1 =$ \\ $ \text {FP}+\text {TP}$ };
4148+ %
4149+ \end {tikzpicture }
4150+ \end {center }
4151+ %
4152+ \begin {align* }
4153+ &\text {ACC}=\frac {\text {TN}+\text {TP}}{\text {R}_0+\text {R}_1}
4154+ \qquad
4155+ \text {TNR}=\frac {\text {TN}}{\text {R}_0}
4156+ \qquad
4157+ \text {TPR}=\frac {\text {TP}}{\text {R}_1}
4158+ \\
4159+ &\text {ACC}=\frac {\text {TN}+\text {TP}}{\text {P}_0+\text {P}_1}
4160+ \qquad
4161+ \text {NPV}=\frac {\text {TN}}{\text {P}_0}
4162+ \qquad
4163+ \text {PPV}=\frac {\text {TP}}{\text {P}_1}
4164+ \end {align* }
4165+ %
4166+ \end {frame }
4167+
41244168
4125- \begin {frame }[label=MultiLabelClassification]{Multi-Label Classification with Hidden Layer Model}
4169+
4170+ \begin {frame }[t]{Binary Classification Metrics}
4171+ %
4172+ $ \cdot $ TNR = specificity / selectivity, NPV = ?, TPR = sensitivity / recall, PPV = precision
4173+
4174+ $ \cdot $ metric based on TNR and TPR
4175+
4176+ $ \cdot $ metric based on TNR and NPV and/or TPR and PPV
4177+
4178+ $ \cdot $ TPR vs. PPV extrem cases
4179+ \begin {align* }
4180+ &\text {TPR}=\frac {\text {TP}}{\text {R}_1}=\frac {\text {TP}}{\text {TP}+\text {FN}}
4181+ &\text {PPV}=\frac {\text {TP}}{\text {P}_1}=\frac {\text {TP}}{\text {TP}+\text {FP}}\\
4182+ &\text {TPR}\approx 0: \text {FN} \gg \text {TP},\,\,\, \text {TP} \approx 0
4183+ &\text {PPV}\approx 0: \text {FP} \gg \text {TP},\,\,\, \text {TP} \approx 0\\
4184+ &\text {TPR}\approx 1: \text {TP} \gg \text {FN},\,\,\, \text {FN} \approx 0
4185+ &\text {PPV}\approx 1: \text {TP} \gg \text {FP},\,\,\, \text {FP} \approx 0\\
4186+ \end {align* }
4187+ %
4188+ $ \cdot $ $ \text {TPR}\approx 1 $ and $ \text {PPV}\approx 0 $ : few FN but many FP (e.g. overestimation of infections)
4189+
4190+ $ \cdot $ $ \text {TPR}\approx 0 $ and $ \text {PPV}\approx 1 $ : few FP but many FN (e.g. underestimation of infections)
4191+
4192+ $ \cdot $ a potentially meaningful(?!) average (harmonic mean)
4193+ $$
4194+ \left (\frac {\frac {1}{\text {TPR}} + \frac {1}{\text {PPV}}}{2}\right )^{-1}
4195+ =
4196+ 2 \cdot \frac {\text {TPR}\cdot\text {PPV}}{\text {TPR}+\text {PPV}}
4197+ =
4198+ 2 \cdot \frac {\text {recall}\cdot\text {precision}}{\text {recall}+\text {precision}}
4199+ =F_1 \,\,\, \text {score}
4200+ $$
4201+
4202+ \end {frame }
4203+
4204+
4205+
4206+ \begin {frame }[label=MultiLabelClassification]{Multi-Label Classification with Hidden Layer and Sigmoid Output Model}
41264207%
41274208\vspace {-0.25cm}
41284209\begin {center }
@@ -4192,7 +4273,7 @@ \subsection{Exercise 13}
41924273\end {bmatrix}
41934274$ };
41944275%
4195- \node [](sigmoid) at (9.5,0)[]{sigmoid $ \sigma _3 (\cdot )$ };
4276+ \node [](sigmoid) at (9.5,0)[]{\underline { sigmoid} $ \sigma _3 (\cdot )$ };
41964277%
41974278\end {tikzpicture }
41984279\end {center }
@@ -4246,95 +4327,6 @@ \subsection{Exercise 13}
42464327
42474328
42484329
4249-
4250-
4251-
4252-
4253-
4254-
4255-
4256- \begin {frame }[t]{Confusion Matrix for Binary Classification}
4257- %
4258- \begin {center }
4259- \begin {tikzpicture }[scale=1.25]
4260- \tikzstyle {mtxi}=[draw, shape=rectangle,minimum size=1.5cm]
4261- \tikzstyle {mtxo}=[draw=none, shape=rectangle,minimum size=0.5cm]
4262- \node [mtxi, align=center](tn) at (-0.75,+0.75){$ \textcolor {C0}{0} | \textcolor {C3}{0}$ \\ TN\\ \textcolor {C3}{0},\textcolor {C0}{0}};
4263- \node [mtxi, align=center](fp) at (+0.75,+0.75){$ \textcolor {C0}{1} | \textcolor {C3}{0}$ \\ FP\\ \textcolor {C3}{0},\textcolor {C0}{1}};
4264- \node [mtxi, align=center](fn) at (-0.75,-0.75){$ \textcolor {C0}{0} | \textcolor {C3}{1}$ \\ FN\\ \textcolor {C3}{1},\textcolor {C0}{0}};
4265- \node [mtxi, align=center](tp) at (+0.75,-0.75){$ \textcolor {C0}{1} | \textcolor {C3}{1}$ \\ TP\\ \textcolor {C3}{1},\textcolor {C0}{1}};
4266- %
4267- \node [mtxo, align=center](realtrue) at (-1.5,+0.75){$ \textcolor {C3}{0}$ };
4268- \node [mtxo, align=center](realfalse) at (-1.5,-0.75){$ \textcolor {C3}{1}$ };
4269- \node [mtxo, align=center](predtrue) at (-0.75,+1.5){$ \textcolor {C0}{0}$ };
4270- \node [mtxo, align=center](predfalse) at (+0.75,1.5){$ \textcolor {C0}{1}$ };
4271- %
4272- \node [mtxo, align=center, rotate=90](reallbl) at (-1.75,0){\textcolor {C3}{real} class};
4273- \node [mtxo, align=center](predlbl) at (0,1.75){\textcolor {C0}{predicted} class};
4274- %
4275- \node [mtxo, align=left](realfalse) at (2.25,+0.75){$ \text {R}_0 = \text {TN}+\text {FP}$ };
4276- \node [mtxo, align=left](realtrue) at (2.25,-0.75){$ \text {R}_1 = \text {FN}+\text {TP}$ };
4277- %
4278- \node [mtxo, align=center](predfalse) at (-0.75,-1.75){$ \text {P}_0 =$ \\ $ \text {TN}+\text {FN}$ };
4279- \node [mtxo, align=center](predtrue) at (+0.75,-1.75){$ \text {P}_1 =$ \\ $ \text {FP}+\text {TP}$ };
4280- %
4281- \end {tikzpicture }
4282- \end {center }
4283- %
4284- \begin {align* }
4285- &\text {ACC}=\frac {\text {TN}+\text {TP}}{\text {R}_0+\text {R}_1}
4286- \qquad
4287- \text {TNR}=\frac {\text {TN}}{\text {R}_0}
4288- \qquad
4289- \text {TPR}=\frac {\text {TP}}{\text {R}_1}
4290- \\
4291- &\text {ACC}=\frac {\text {TN}+\text {TP}}{\text {P}_0+\text {P}_1}
4292- \qquad
4293- \text {NPV}=\frac {\text {TN}}{\text {P}_0}
4294- \qquad
4295- \text {PPV}=\frac {\text {TP}}{\text {P}_1}
4296- \end {align* }
4297- %
4298- \end {frame }
4299-
4300-
4301-
4302- \begin {frame }[t]{Binary Classification Metrics}
4303- %
4304- $ \cdot $ TNR = specificity / selectivity, NPV = ?, TPR = sensitivity / recall, PPV = precision
4305-
4306- $ \cdot $ metric based on TNR and TPR
4307-
4308- $ \cdot $ metric based on TNR and NPV and/or TPR and PPV
4309-
4310- $ \cdot $ TPR vs. PPV extrem cases
4311- \begin {align* }
4312- &\text {TPR}=\frac {\text {TP}}{\text {R}_1}=\frac {\text {TP}}{\text {TP}+\text {FN}}
4313- &\text {PPV}=\frac {\text {TP}}{\text {P}_1}=\frac {\text {TP}}{\text {TP}+\text {FP}}\\
4314- &\text {TPR}\approx 0: \text {FN} \gg \text {TP},\,\,\, \text {TP} \approx 0
4315- &\text {PPV}\approx 0: \text {FP} \gg \text {TP},\,\,\, \text {TP} \approx 0\\
4316- &\text {TPR}\approx 1: \text {TP} \gg \text {FN},\,\,\, \text {FN} \approx 0
4317- &\text {PPV}\approx 1: \text {TP} \gg \text {FP},\,\,\, \text {FP} \approx 0\\
4318- \end {align* }
4319- %
4320- $ \cdot $ $ \text {TPR}\approx 1 $ and $ \text {PPV}\approx 0 $ : few FN but many FP (e.g. overestimation of infections)
4321-
4322- $ \cdot $ $ \text {TPR}\approx 0 $ and $ \text {PPV}\approx 1 $ : few FP but many FN (e.g. underestimation of infections)
4323-
4324- $ \cdot $ a potentially meaningful(?!) average (harmonic mean)
4325- $$
4326- \left (\frac {\frac {1}{\text {TPR}} + \frac {1}{\text {PPV}}}{2}\right )^{-1}
4327- =
4328- 2 \cdot \frac {\text {TPR}\cdot\text {PPV}}{\text {TPR}+\text {PPV}}
4329- =
4330- 2 \cdot \frac {\text {recall}\cdot\text {precision}}{\text {recall}+\text {precision}}
4331- =F_1 \,\,\, \text {score}
4332- $$
4333-
4334- \end {frame }
4335-
4336-
4337-
43384330\subsection {Exercise 14 }
43394331
43404332\begin {frame }{Ex14: Multi-Class Classification with Softmax Output Layer}
@@ -4476,7 +4468,7 @@ \subsection{Exercise 14}
44764468
44774469\againframe {MultiLabelClassification}
44784470%
4479- \begin {frame }{Multi-Class Classification with Hidden Layer Model}
4471+ \begin {frame }{Multi-Class Classification with Hidden Layer and Softmax Output Model}
44804472%
44814473\vspace {-0.25cm}
44824474\begin {center }
@@ -4546,7 +4538,7 @@ \subsection{Exercise 14}
45464538\end {bmatrix}
45474539$ };
45484540%
4549- \node [](sigmoid) at (9.5,0)[]{softmax $ \sigma _3 (\cdot )$ };
4541+ \node [](sigmoid) at (9.5,0)[]{\underline { softmax} $ \sigma _3 (\cdot )$ };
45504542%
45514543\end {tikzpicture }
45524544\end {center }
@@ -4596,7 +4588,7 @@ \subsection{Exercise 14}
45964588
45974589
45984590
4599- \begin {frame }{Softmax Activation Combined With Categorical Cross Entropy}
4591+ \begin {frame }{Softmax Activation Output Combined With Categorical Cross Entropy}
46004592
46014593$ \cdot $ $ \hat {y}_{i=1 \dots K} \in \mathbb {R}$ model outputs with $ K$ mutual exclusive classes
46024594
@@ -4629,7 +4621,7 @@ \subsection{Exercise 14}
46294621
46304622
46314623
4632- \begin {frame }{Multi-Class Classification with Hidden Layer Model}
4624+ \begin {frame }{Multi-Class Classification with Hidden Layer and Softmax Output Model}
46334625%
46344626\vspace {-0.25cm}
46354627\begin {center }
@@ -4699,7 +4691,7 @@ \subsection{Exercise 14}
46994691\end {bmatrix}
47004692$ };
47014693%
4702- \node [](sigmoid) at (9.5,0)[]{softmax $ \sigma _3 (\cdot )$ };
4694+ \node [](sigmoid) at (9.5,0)[]{\underline { softmax} $ \sigma _3 (\cdot )$ };
47034695%
47044696\end {tikzpicture }
47054697\end {center }
@@ -4851,7 +4843,7 @@ \subsection{Exercise 14}
48514843\node [mtxo, align=center](predlbl) at (0,2){\textcolor {C0}{predicted} class};
48524844%
48534845\node at (0,-2){100\% percent per row};
4854- \node at (0,-3){good for unbalanced classes};
4846+ \node at (0,-3){good for (un)balanced classes};
48554847\end {scope }
48564848%
48574849\end {tikzpicture }
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