Questions tagged [logistic-regression]
Refers generally to statistical procedures that utilize the logistic function, most commonly various forms of logistic regression
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How to learn from time series with multiple values for each time points
A multivariate time-serie has more than one time-dependent variable and it is my case.
Still for each time I have not one entrie of dependent variables but many entries, like:
...
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1answer
8 views
In handwritten digit recognition problem using logistic regression, what changes needed to add another class “Not a Digit”
In handwritten digit recognition problem using logistic regression, normal implementation would forcibly classify even a picture of dog or cat as a digit. To eliminate this, what changes are needed to ...
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Perceptron on Logistic Regression
I have already did the training for the data but I am not sure how to do the rest. I just need someone to explain how I should proceed?
Implement a perceptron for logistric regression. For your ...
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Logistic Regression with Non-Integer feature value
Hi I was following the Machine Learning course by Andrew Ng. I found that in regression problems, specially logistic regression they have used integer values for the features which could be plotted in ...
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24 views
Logistic regression from scratch in Python
Here is my logisticRegression class I developed to do gradient descent. There is this one line I marked as problematic
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1answer
17 views
logistic regression score is negative
I am trying to implement logistic regression algorithm.
I am using sklearn for this purpose.When I am printing the accuracy its printing negative value.
code:
...
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1answer
24 views
How does combining neurons create non-linear boundaries?
I have been working with NNs for a while, but haven't dug too deep into this unfortunately.
By looking at the three neurons below, in each of their boxes we can see that they are really just making ...
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15 views
Baseline for Multinomial Logistic Regression in Scikit-learn
I am trying to get the coefficients for my multinomial logistic regression model in Sklearn . However, I am confused what is the baseline if I have more than 2 targets. I need to know since I need to ...
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Logistic Regression with Tensorflow
Is this the correct Estimator for Logistic Regression in TF 1.10?
There used to be a function called: LogisticRegressor which is deprecated
In README.md file it ...
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2answers
52 views
C++ return array from function
I would like to implement machine learning algorithm in C++ without using any C++ machine learning library. So I'm writing this initializer function for generating zero matrices but can't figure out ...
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How to choose Elastic-Net parameters for feature selection?
I recently came across using elastic nets for feature selection which brings in regularization to temper the sparsity properties of L1 regressions.
I would like to learn how to use elastic nets for ...
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comparison of linear Q-learning and DQN
I saw in DQN nature paper 2015 https://www.nature.com/articles/nature14236(Extended Data Table 4) some comparisons between DQN and linear Q-learning.
The ratio ...
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1answer
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Free parameters in logistic regression
When applying logistic regression, one is essentially applying the following function $1/(1 + e^{\beta x})$ to provide a decision boundary, where $\beta$ are a set of parameters that are learned by ...
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Comparing the performance (reward) of dqn and logistic q-learning?
I have tried to compare my DQN results (rewards) with logistci q-learning (omitting the hidden layer, just inputs and outputs with a sigmoid activation function)
My rewards of logistic-Q-N is about 5-...
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2answers
39 views
Logistic Regression Cost Function: Gives mathematical error since its attempting to calculate log(0)
I am learning machine learning and after reading through materials on logistic regression i attempted to implement logistic regression with gradient descent in python from scratch.
It works well for ...
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1answer
75 views
Dealing with NaN (missing) values for Logistic Regression- Best practices?
I am working with a data-set of patient information and trying to calculate the Propensity Score from the data using MATLAB. After removing features with many missing values, I am still left with ...
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1answer
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best activation function for ensemble?
i have created some logistic regression model (different preprocessing) with softmax function. and i mix all model with an ensemble with a hierarchical method. so the output of all model (base) will ...
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1answer
28 views
Target data values are not evenly distributed
Data nature:
I have features with 10 numeric type, and other 10 categorical, with a lot of values, at the end, using one-hot encoding I got a matrix of 600 columns. My problem is with accuracy ...
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1answer
140 views
TypeError: object of type 'int' has no len(), LogisticRegression()
I'm trying to fit my Logistic Regression model, but I'm running into an error that I don't understand. Looked around and haven't found a straight answer.
Shape of independent features (X): (495,30)
...
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1answer
63 views
Capturing movement importance - logistic regression output
I'm studying some event for a set of objects that can be plotted on a square $[0, 100] ^ 2$. I have used logistic regression to calculate probabilities that event occur for different objects and the ...
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Why is the logistic regression decision boundary linear in X?
The logistic regression model,
\begin{equation}
\operatorname{p}(X) = \frac{\operatorname{e}^{\beta_0 + \beta_1 X}}{1 + \operatorname{e}^{\beta_0 + \beta_1 X}}
\end{equation}
is said to create a ...
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2answers
80 views
What are the differences between logistic and linear regression?
I know that linear regression does "regression" and logistic regression does "classification". When we implement these two methods, the only difference I could notice is the loss function: linear ...
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1answer
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Super basic logistic regression example
I am new to ML and I created a super basic logistic regression example with 4 points on the $x$ line that belong to two classes:
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1answer
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MinMaxScaler returned values greater than one
Basically I was looking for a normalization function part of sklearn, which is useful later for logistic regression.
Since I have negative values, I chose MinMaxScaler with like so: ...
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1answer
240 views
What is the difference between SGD classifier and the Logisitc regression?
To my understanding, the SGD classifier, and Logistic regression seems similar.
An SGD classifier with loss = 'log' implements Logistic regression and loss = 'hinge' implements Linear SVM. I also ...
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Can I use MCA on categorical features, and PCA on numeric then combine both for learning
So all is said in the title. I have a mix of both categorical and numeric features, both are more than 20 columns and reside in the same data-set.
I am using PCA solution from sklearn.decomposition ...
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1answer
81 views
Purpose of backpropagation in neural networks
I've just finished conceptually studying linear and logistic regression functions and their optimization as preparation for neural networks.
For example, say we are performing binary classification ...
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1answer
38 views
Confusion Matrixs for Binary classifier
I am new to modeling, and I am practicing building a logistic regression model. I would like to create a confusion matrix, but my code doesn't seem to work.
Here is the code for the model (which ...
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1answer
34 views
Decomposing R squared or VIF
In the context of multi-regression, I am wondering if there is a way to decompose $$VIF_i = 1/(1-R_i^2)$$ where $R_i^2$ is the r squared obtained from the regression of dependent variable = i and ...
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1answer
44 views
Why does Bagging or Boosting algorithm give better accuracy than basic Algorithms in small datasets?
I was working with a small dataset, with 392 values, and it was kind of an imbalanced dataset, with 262 values belonging to class 1 and rest 130 to class 0. So I did the upsampling technique, ...
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1answer
203 views
Should highly correlated features be omitted before applying Lasso?
I would greatly appreciate if you could let me know whether I should omit highly correlated features before using Lasso logistic regression (L1) to do feature ...
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1answer
37 views
Classification models with multi-class allowed for each record
I am training a multi-class classification model. Each record can belong to one or more classes. (actually can I still call it a classification model? or should it ...
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1answer
30 views
Logistic Regression or regression SVM for probability of outcome
I am working on a prediction question: what's the percentage of Y = 1 using a number of features?
The output Y values I have for training are in binary. In this case, should the prediction be ...
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1answer
28 views
Gradient descent multidimensional linear regression - does learning rate affects concurrency? [closed]
I wonder if gradient descent for multidimensional regression always finds the right result? I feel like this doesn't always have to be true. I have done some calculations and actually got correct ...
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Octave fminunc error: “Trust region radius became excessively small”
I am trying to run a linear regression using fminunc to optimize my parameters. However, while the code never fails, the fminunc function seems to only be running once and not converging. The exit ...
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Logistic Regression sklearn vs matlab Different Answers
Years ago I built a model in Matlab that used glmfit(X, Y, 'binomial, 'link', 'logit') and I am now trying to transfer the model to python using sklearn (i.e sklear.linear_model.LogisticRegression).
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2answers
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Binomial family in logistic regression
I was asked in an interview why do we use the binomial distribution in logistic regression and how is it related to the class that we are predicting?
Could anyone explain, without any mathematical ...
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Machine Learning: Stochastic gradient descent method for logistic regression in R
I am trying to write a code to solve the following problem (As stated in HW5 in the CalTech course Learning from Data):
In this problem you will create your own target function f (probability in this ...
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How does binary cross entropy work?
Let's say I'm trying to classify some data with logistic regression.
Before passing the summed data to the logistic function (normalized in range $[0,1]$), weights must be optimized for desirable ...
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Direct Mail Response Modelling
Hi, I have a question regarding Direct Mail response model performance.
I created a model based on previous DM campaign responders and non-responders.
Applied it on the new prospects and calculated ...
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1answer
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Why is patsy used to prepare data for logistic regression?
I'm pretty new to both ML & scikit-learn. I've noticed that some example tutorials & codes online use patsy's dmatrices to prepare data for logistic regression. I don't understand why this is ...
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Kernel Logistic Regression: Training vs Test Kernel
I'm currently implementing the Kernel Logistic Regression (KLR) for binary classification. I have split my data sets into training and testing with the number of test observations far greater than the ...
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How to format data for localized image classification in Keras?
I have a bunch of image files and, for each image, an associated csv file that contains coordinates, and a label. This indicates a label of a specific part of the image. I want to train a neural ...
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261 views
Is this the correct use of SelectKBest? Predictive accuracy drops
I have the following code here:
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1answer
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Interpreting lasso logistic regression feature coefficients in multiclass problem
I have a dataset with a large number of text features, where the target variable has three classes.
I have encoded the features using tf-idf. This has resulted in a dataset with an extremely large ...
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When should the bias b be updated with weights w and when should it be updated seperately?
It seems in some Machine Learning models, the bias term $b$ is updated just like other weights $w_i, i=1...n$. For example, in Logistic Regression, using SGD, $b \ \text{or} \ w_0$ is updated with:
$$...
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3answers
669 views
Is this a good practice of feature engineering?
I have a practical question about feature engineering... say I want to predict house prices by using logistic regression and used a bunch of features including zip code. Then by checking the feature ...
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1answer
209 views
Why do we need the sigmoid function in logistic regression?
What is the purpose of the logistic sigmoid function as it is used in logistic regression? Why does it need to be part of the hypothesis function h(x) ?
As I understand it, the logistic sigmoid ...
