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Questions tagged [convergence]

303 questions
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hierarchical model of study - can I use mixed effects in r?

This is a study in which 3 mice were used as control, and 3 were mutant. >2000 measurements were taken per mouse. I want to fit a model as follows: lmer(measurements ~ mouseID + (mouseID|treatment), data = alldata, REML = TRUE) but this does not…
kriggs
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Evaluating convergence of a random variable (unknown expected value)

I have a stochastic simulation model that produces random deviates of a variable, whose expected value is unknown. I would like to determine the minimal number of simulations necessary to obtain convergence of the mean of the random variable. For…
sebastien1785
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Pythorch: Dictionary learning with Neural Networks. Adam Opt does not converge

I have implemented a code based on the paper of https://arxiv.org/pdf/1707.00225.pdf However, the algorithm 1 of the paper (which is basically 2 steps: first step you calculate K with the parameters of the NN, and second step is to apply gradient…
crc15
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Least Squares: I obtain convergence only changing '+' into a '-'

During the least squares computation: x = N(-1) * At * Q(-1) * (yo -b) Instead of doing: Xnew = Xold + x[0] Ynew = Yold + x[1] In order to obtain the convergence I have to change the '+' into a '-': Xnew = Xold - x[0] Ynew = Yold -…
Chiara
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mmultilevel mixed effect model convergence and gradient errors

I'm fitting a model and carrying out backwards elimination. I've got to a point where a likelihood ratio test shows there is a significant difference in the model output if I exclude any more of the predictors, so the final model is…
wils
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Multinomial logit with random effects does not converge using mblogit

I would like to estimate a random effects (RE) multinomial logit model. I have been applying mblogit from the mclogit package. However, once I introduce RE into my model, it fails to converge. Is there a workaround this? For instance, I tried to…
Barbora
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OpenMDAO hierarchical solvers recording

In OpenMDAO, is there any recommendation on how to record and read solver cases if the model is composed of multiple groups/cycles, and multiple nonlinear solvers? I have a model built of 2 cycles (cycle1 and cycle2), one of them containing two…
Kasia
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Use neural netword to fit a reduced boolean function, but found the super-params not as expected

This is the boolean function I try to fit. [boolean function description][1] Theoretically we need a neural network with 1 hidden layer which has 3 neurons at least. And that's actually how I built the neural network in Pytorch. However, despite the…
Richard Frank
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Why does my k-means convergence condition give different results than sklearn?

I've written a function that executes k-means clustering with data, K, and n (number of iterations) as inputs. I can set n=100 so that the function calculates Euclidean distance, assigns clusters and calculates new cluster centroids 100 times over…
Brudalaxe
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gradient descent doesn't change in my linear regression implementation

I am beginner in gradient descent concept . I implemented a multivariate linear regression with gradient descent optimization algorithm. but my program doesn't converge and just early iteration has small changes! my methods(in my class) is…
amir1122
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A way to estimate a converged result based on converging numerical data in python?

I have pairs of data arrays (say x_n and y_n), which represent some result y_n(x) that converges with n. -These arrays become more densely populated for larger n. -There are no common elements in any x_n arrays. -The data itself cannot be fitted. -I…
lightfield
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scipy.optimize.minimize does not converge in multivariable optimization

I want to find the values of board_trim and lm that will give me the lowest (closest to 0) value for Board_Moments. For this I use scipy.optimize.minimize, but it does not converge. I really can't figure it out. with Parameters: displacement = 70 b…
Jaume Triay
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glmer: logistic regression model failed to converge

In my project, I am looking at the acceptance probabilities of technical proposals in an organizational context. I have data over a 20 year period and my data set contains the following information: whether the proposal was accepted or not (binary…
iwkg_de
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drm() Error Convergence failed for some data but not for similar?

I'm trying to loop over some dose-dependent data and fit it using the drm() function. However, for some of the data I get the following error: Error in optim(startVec, opfct, hessian = TRUE, method = optMethod, control = list(maxit = maxIt, …
Norruas
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Convergence issues of survey data

I am trying to fit a linear mixed model to a food purchase dataset to test the trend of the purchase of ultra-processed food between different social-economic groups over five years. Roughly about 10000 households have been sampled each year (most…
Polly
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