Recent questions tagged machine-learning

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A binary classification problem could be solved with the two approaches described below:Approach 1 : Simple Logistic Regression (one neuron)Your output will be $\hat y = ...
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Given input data $x \in \mathbb{R}^3$ , how many parameters do the following models have? Assume that linear components of all models have bias terms.Binary logistic regr...
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Given a vector $a = [0.3, 0.3, 0.3]$, what is the result of using softmax activation on this vector?$[1, 1, 1]$$[\frac{1}{2}, \frac{1}{2}, \frac{1}{2}]$$[\frac{1}{3}, \fr...
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James likes big cats. He has a collection of color images, each of which has been accurately labeled as being a leopard, jaguar, cheetah, or lion. He wishes to design a 4...
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Given an $n$-dimensional vector $y$ :For any real number $c$, will the softmax of $c \cdot y$ b e the same as the softmax of $y$?(Please enter 1 for True and 0 for False)
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What is the definition of $softmax(x_1,..,x_n)$? Recall that this function takes in a list of $n$ real numbers $x_1,..., x_n$ and outputs a list of $n$ real numbers. $sof...
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We trained a three-way logistic regression and obtained weights$$w_a = (1,1, 0), w_b = (-1,1,1), w_c = (2,1,2)$$.What label would be given to the point $x = (0, 1, 1)$?A ...
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Consider the probability of a label $y_n$ given an input vector $x_n$ and parameter vector $w$ for a binary classification problem, where $y_n \in \{+1, - 1\}$. The proba...
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Given the probability model for a binary classification problem where the label $y_n \in \{ + 1 , -1\} $and the probability is defined as,$$P(y_n \mid x_n) = \begin{cases...
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Consider the probability of a label yn given an input vector $X_n$ and parameter vector $w$ for a binary classification problem, where $y_n \in \{+1, - 1|\}$. The probabi...
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Let's think about what happens with linearly separable data in logistic regression. Consider the following training set on the right:Each data point has two features - on...
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Which of the following statements are true about logistic regression? 1. If the points are linearly separable (with a positive margin), then logistic regression (with ...
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If no regularization is used and the training data is linearly separable, the optimal model parameters will tend towards positive or negative infinity.(Please enter 1 for...
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Consider the following scatter plot of our two (standardized) features. Which of the following statements are true about an unregularized logistic regression model fit on...
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Suppose you have a logistic regression model for spam detection, using a dataset with a binary outcome that indicates whether an email is spam (1) or not spam (0). The pr...
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Which of the following models can be learned by MLE ? Perceptron Ridge regression SVMs Logistic regression
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There are 5 balls in a bag. Each ball is either red or blue. Let $\theta$ (an integer) be the number of blue balls. We want to estimate $\theta$, so we draw 4 balls with ...
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$\text { Consider the following probability distribution: }$$$P_\theta(x)=2 \theta x e^{-\theta x^2}$$where $\theta$ is a parameter and $x$ is a positive real number. Sup...
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You are walking down Shattuck Ave. when you find a quarter on the ground. You see nothing unusual about this quarter, so you figure it is almost certainly a fair coin, th...
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Suppose that $X$ is a discrete random variable with the following probability mass function: where $0 \leq \theta \leq 1$ is a parameter. The following 10 independent obs...
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For the given statements about cross-entropy loss.$(i)$ The value of cross-entropy loss is always non-negative.$(ii)$ Minimizing the cross-entropy is equivalent to maximi...
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Suppose a classifier predicts each possible class with equal probability. If there are 10 classes, what will the cross-entropy error be on a single example ? $-\log (10) ...
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$\text { Which function is not a convex function ? }$Sigmoid/Logistic function: $f(x)=1 /\left(1+e^{-x}\right)$.Linear function: $f(x)=3 x$.Square function: $f(x)=x^2$.f(...
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Let $f: \mathbb{R} \rightarrow \mathbb{R}$ be the function $f(x)=\frac{1}{1+e^{-x}}$The value of the derivative of $f$ at $x$ where $f(x)=0.4$ is__________(rounded off to...
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Consider the sigmoid function defined as:$$\sigma(z)=\frac{1}{1+e^{-z}}$$Which of the following options correctly represents the derivative of the sigmoid function with r...
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For a binary classification problem, where the true class label $C \in\{0,1\}$, the cross-entropy loss is defined based on the predicted probability $P_C$ that a data poi...
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In this question, assume that we are using the logistic regression model $\hat{y}=\sigma\left(x^T \theta\right)$.Suppose we want to modify cross-entropy loss to penalize ...
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Suppose after training our model we get $\vec{\beta}=\left[\begin{array}{lll}-1.2 & -0.005 & 2.5\end{array}\right]^T$, where -1.2 is an intercept term, -0.005 is the para...
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Suppose after training our model we get $\vec{\beta}=\left[\begin{array}{lll}-1.2 & -0.005 & 2.5\end{array}\right]^T$, where -1.2 is an intercept term, -0.005 is the para...
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In this question, assume that we are using the logistic regression model $\hat{y}=\sigma\left(x^T \theta\right)$.Suppose we want to modify cross-entropy loss to penalize ...