Data Science Stack Exchange
Data Science Stack Exchange

Questions tagged [parameter]

40 questions
65
votes
6 answers

When is a Model Underfitted?

Logic often states that by underfitting a model, it's capacity to generalize is increased. That said, clearly at some point underfitting a model cause models to become worse regardless of the complexity of data. How do you know when your model has…
blunders
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7 answers

What is the difference between model hyperparameters and model parameters?

I have noticed that such terms as model hyperparameter and model parameter have been used interchangeably on the web without prior clarification. I think this is incorrect and needs explanation. Consider a machine learning model, an SVM/NN/NB based…
minerals
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What does the alpha and beta hyperparameters contribute to in Latent Dirichlet allocation?

LDA has two hyperparameters, tuning them changes the induced topics. What does the alpha and beta hyperparameters contribute to LDA? How does the topic change if one or the other hyperparameters increase or decrease? Why are they hyperparamters…
alvas
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3 answers

What is the correct way to compute Mean F1 score?

I have a set of 10 experiments that compute precision, recall and f1-score for each experiment. Now, average precision & average recall is easy to compute. I have some confusion regarding average f1-score. There are 2 ways on how i can compute mean…
Pinkesh Badjatiya
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7
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3 answers

Regression model with variable number of parameters in dataset?

I work in physics. We have lots of experimental runs, with each run yielding a result, y and some parameters that should predict the result, x. Over time, we have found more and more parameters to record. So our data looks like the following: Year 1…
JoseOrtiz3
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7
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1 answer

Choosing a window size for DTW

I have time series data from mobile sensors for different motions such as walking, pushups, dumbellifts, rowing and so on. All these motions have different length of time series. For classifying them using Dynamic Time Warping (DTW), how do I choose…
Nitin Labhishetty
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2 answers

"Relearning" parameters

If this is a duplicate, I apologize. I'm not really sure what to even search for to try and find a duplicate/answer! We are working on a system for providing musical feedback to change the 'mood' of a subject. There are a number of parameters of the…
Brennon Bortz
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4
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1 answer

Parameter estimation: reduce time

I have a two-class prediction model; it has n configurable (numeric) parameters. The model can work pretty well if you tune those parameters properly, but the specific values for those parameters are hard to find. I used grid search for that…
oopcode
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3
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3 answers

What are the best ways to tune multiple parameters?

When building a model in Machine Learning, it's more than common to have several "parameters" (I'm thinking of real parameter like the step of gradient descent, or things like features) to tune. We validate these parameters on a validating set. My…
jmvllt
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Max pooling has no parameters and therefore doesn't affect the backpropagation?

I feel this is a question that has a lot of variations already posted but it doesn't exactly answer my question. I understand the concept of max pooling and also the concept of backpropagation. What i cannot understand is that why is it said that…
need_to_know_now
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1 answer

What is the difference of R-squared and adjusted R-squared?

I have in mind that R-squared is the explained variance of the response by the predictors. But i'd like to know how the adjusted value is computed ? and if the concept has any change from the original.
Rafael Toledo
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How does C have effects on bias and variance of a Support Vector Machine?

The minimization problem for SVM can be written as- $$\overset{\text{min}}{\theta} C\sum_{i = 1}^{m}{[y^icost_1(\theta^Tx^i) + (1-y^i)cost_0(\theta^Tx^i)]} + \frac12\sum_{j = 1}^n{\theta_j}^2$$ Now, how can the choice of $C$ lead to underfitting or…
truth
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how to find the best parameters to solve a differential equation?

I have a differential equation: def func(Y, t, r, p, K, alpha): return r * (Y ** p) * (1 - (Y / K) ** alpha) and I want to find the best parameters that fit (r,p,K,alpha). I tried to use curve fit but it was too bad, this is my code # I chose…
Hassan
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0 answers

Four parameter self-starting function based on SSfpl

I am currently working with a self-starting function for four parameters which I based on SSfpl but with a different formula. This is the formula for my self-starting function: (b1 * ((b2 * x)^b4)) / (1 + ((b2 * x)^b4))^(b3 / b4) The code below is…
HYDR0GEN
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1 answer

Finding parameters with extreme values (classification with scikit-learn)

I am currently working with the forest cover type prediction from Kaggle, using classification models with scikit-learn. My main purpose is learning about the different models, so I don't pretend to discuss about which one is better. When working…
cpumar
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