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Questions tagged [weighted-data]

The tag has no usage guidance.

3
votes
1answer
39 views

CNN - imbalanced classes, class weights vs data augmentation

I have a set of data with a few strongly imbalanced classes, eg the smallest class is about 54 times smaller than the largest. Therefore, data augmentation in order to equalize the size of classes ...
1
vote
1answer
21 views

How are weights calculated in a feed-forward neural network before they are summed up with bias?

I have read a lot of papers and watched different videos, it seems like they explain how they are summed up with bias before entering the activation function. What I am trying to understand is the ...
0
votes
0answers
17 views

String Matching columns based on weight

I have the following 2 DataFrames and want to match skills to the key_skills column based on weights. for eg: suppose student 1-{python, Java} job - {python, Ruby, Perl, etc } weight = 1 In the end,...
1
vote
1answer
46 views

Why doesn't class weight resolve the imbalanced classification problem?

I know that in imbalanced classification, the classifier tends to predict all the test labels as larger class label, but if we use class weight in loss function, it would be reasonable to expect the ...
0
votes
0answers
5 views

Appropriate math for evaluating coverage/fit across multiple weighted many-to-many relationships

Generally speaking, my current problem involves assigning people to jobs. Each job entails a set of tasks, each task requires some array of skills, and each skill is possessed by some subset of people....
1
vote
1answer
57 views

Calculate weighted mean for two columns and hundreds of rows?

I'm trying to teach myself basics of R and I couldn't find the answer: Say, I have a csv file and I want to calculate weighted mean for each subject such that I have a mean mu = 0.015*1030+0.16*26930+...
1
vote
1answer
524 views

How to apply class weight to a multi-output model?

I have a model with 2 categorical outputs. The first output layer can predict 2 classes: [0, 1] and the second output layer can predict 3 classes: [0, 1, 2]. How can I apply different class weight ...
3
votes
3answers
393 views

using sklearn class weight to increase number of positive guesses in extremely unbalanced data set?

Hi I have a poorly correlated and unbalanced data set I have to work with. The set is 2 classes, 0 has 96,000 values and 1 has about 200. When I run random forest or other methods I get an output like:...
1
vote
0answers
47 views

How to weight loss in regression

I've got a regression problem where a model is required to predict a value in the range [0, 1]. I've tried to look at the distribution of the data and and it seems that there are more examples with ...
0
votes
1answer
393 views

Class weights for imbalanced data in multilabel problems

I am trying to train a CNN for a multiclass - multilabel classification task (20 classes, each sample can belong to 1+ labels) and the dataset is highly imbalanced. In single-label cases I would use ...
2
votes
0answers
162 views

How to use class_weight parmater for validation set?

I am using Keras' class_weight parameter to deal imbalanced class problem. So I am doing like this to define the weights : ...
0
votes
1answer
30 views

Differentiating roadmap of a loss function

Let's say I'm performing Stochastic Gradient Descent (SGD) on binary cross entropy error while optimizing weight $w_{2}$. Binary cross entropy error: $$L(y|p(x_{i}))=-y_{i}*ln(p(x_{i}))-(1-y_{i})*...
2
votes
1answer
3k views

How to set class-weight for imbalanced classes in KerasClassifier while it is used inside the GridSearchCV?

Could you please let me know how to set class-weight for imbalanced classes in KerasClassifier while it is used inside the ...
3
votes
2answers
3k views

Sample Importance (Training Weights) in Keras

How do you add more importance to some samples than others (sample weights) in Keras? I'm not looking for class_weightwhich is a fix for unbalanced datasets. ...
0
votes
2answers
98 views

emphasise some observation weights more than the others

I want to emphasise (increase the weight) of only a subset of data. Lets say I have old and fresh data, I would like to say that old data has to have more weight and therefore has more influence in ...
5
votes
1answer
949 views

Purpose of weights in neural networks

I'm beginner at Neural Networks. After reading multiple articles on wikipedia, i've seen the term "weight" being used a lot, although it is a little confusing. I know, that before the inputs are ...
1
vote
0answers
14 views

Are we allowed to give the weight value for svm's predictors?

I have this public data that has 9 predictors in it and it's labeled with two classes. I tried linear svm on it (by computer) and the accuracy was fascinating. But, I I ran through this problem when ...
-2
votes
1answer
47 views

How to redistribute weightage proportionally?

I want to increase proportional increase weightage. For example, I have weights w1 = 0.4 w2 = 0.3 w3 = 0.2 w4 = 0.1 with a constraint that the total sum of the ...
4
votes
1answer
70 views

Range to define emotions

We are capturing emotions as survey responses. We need to assign values for the responses(emotions) for analysis purposes. Is there an optimum range that can be assigned to achieve this? (like from -...
7
votes
3answers
2k views

Unbalanced class: class_weight for ML algorithms in Spark MLLib

In python sklearn, there are multiple algorithms (e.g. regression, random forest ... etc.) that have the class_weight parameter to handle unbalanced data. However, I do not find such parameter for ...
0
votes
2answers
291 views

Calculate feature weight vector for one-hot-encoded data frame in R

I have the following data frame with one categorical and two numerical columns: V1 V2 V3 1 A 1 3 2 A 3 5 3 B 3 3 4 C 2 3 I have ...
96
votes
6answers
108k views

How to set class weights for imbalanced classes in Keras?

I know that there is a possibility in Keras with the class_weights parameter dictionary at fitting, but I couldn't find any example. Would somebody so kind to ...
3
votes
1answer
518 views

Sklearn Linear Regression examples

Could someone give an example of the application of Tf-idf with sparse data (lots of zeros) in sklearn? I am not quite sure where to insert the weight of Tf-idf and how to rightly obtain the weight. ...
3
votes
1answer
2k views

How can the process of hypertuning of XGBoost parameters be automated?

I'm using xgboost for training a model on a data with extreme class imbalance. After referring from here. After performing grid search and some manual settings, I ...
4
votes
2answers
1k views

How can give weight to feature before PCA

I wonder how can I give weight to my feature before employing PCA. I mean somehow weighted PCA. Because I know that one of the features is better than others and want to give importance to it in ...
4
votes
1answer
5k views

Machine learning technique to calculate weighted average weights?

I'm just starting to investigate machine learning concepts, so I'm sorry if this question is very naive, but I'm hoping that it will be an easy one to answer! I have a document matching algorithm ...
0
votes
3answers
2k views

@RISK Vs R. Monte Carlo simulation in R?

Are there any cheaper or open source alternatives to @RISK or are there packages for R that would be able to perform the same tasks? http://www.palisade.com/risk/ @RISK (pronounced “at risk”) ...
2
votes
2answers
175 views

Sort by average votes/ratings

I have a data set that's a dictionary of tuples. Each key represents an ID number and each tuple is (yesvotes, totalvotes). Example: ...
17
votes
3answers
20k views

xgboost: give more importance to recent samples

Is there a way to add more importance to points which are more recent when analyzing data with xgboost?
2
votes
2answers
136 views

Creating validation data for model comparison

I am working on building a scoring algorithm for student data, say the attributes are : name, location, age, class, school_name, skill1, skill2, skill3 based ...