mixture-model

MATLAB code for a lot of Gaussian Mixture Model

允我心安 提交于 2019-12-09 22:19:47
问题 I have applied gaussmix function in voicebox MATLAB tools to calculate GMM. However, the code gives me error when I run it for 512 GMM components. No_of_Clusters = 512; No_of_Iterations = 10; [m_ubm1,v_ubm1,w_ubm1]=gaussmix(feature,[],No_of_Iterations,No_of_Clusters); Error using * Inner matrix dimensions must agree. Error in gaussmix (line 256) pk=px*wt; % pk(k,1) effective number of data points for each mixture (could be zero due to underflow) I need 1024 or 2048 Mixtures for Universal

R : function to generate a mixture distribution

心不动则不痛 提交于 2019-12-08 21:24:41
问题 I need to generate samples from a mixed distribution 40% samples come from Gaussian(mean=2,sd=8) 20% samples come from Cauchy(location=25,scale=2) 40% samples come from Gaussian(mean = 10, sd=6) To do this, i wrote the following function : dmix <- function(x){ prob <- (0.4 * dnorm(x,mean=2,sd=8)) + (0.2 * dcauchy(x,location=25,scale=2)) + (0.4 * dnorm(x,mean=10,sd=6)) return (prob) } And then tested with: foo = seq(-5,5,by = 0.01) vector = NULL for (i in 1:1000){ vector[i] <- dmix(foo[i]) }

MATLAB code for a lot of Gaussian Mixture Model

泪湿孤枕 提交于 2019-12-04 15:17:49
I have applied gaussmix function in voicebox MATLAB tools to calculate GMM. However, the code gives me error when I run it for 512 GMM components. No_of_Clusters = 512; No_of_Iterations = 10; [m_ubm1,v_ubm1,w_ubm1]=gaussmix(feature,[],No_of_Iterations,No_of_Clusters); Error using * Inner matrix dimensions must agree. Error in gaussmix (line 256) pk=px*wt; % pk(k,1) effective number of data points for each mixture (could be zero due to underflow) I need 1024 or 2048 Mixtures for Universal Background Model (UBM) construction. Could anyone give me matlab code to calculate GMM for big number of

Implementation of EM algorithm for Gaussian Mixture Models

邮差的信 提交于 2019-11-30 19:04:24
问题 Using the EM algorithm, I want to train a Gaussian Mixture model with four components on a given dataset. The set is three dimensional and contains 300 samples. The problem is that after about 6 rounds of the EM algorithm, the covariance matrices sigma become close to singular according to matlab ( rank(sigma) = 2 instead of 3). This in turn leads to undesired results like complex values evaluating the gaussian distribution gm(k,i) . Furthermore I used the log of the gaussian to account for

Gaussian Mixture Models of an Image's Histogram

点点圈 提交于 2019-11-30 13:40:55
I am attempting to do automatic image segmentation of the different regions of a 2D MR image based on pixel intensity values. The first step is implementing a Gaussian Mixture Model on the image's histogram. I need to plot the resulting gaussian obtained from the score_samples method onto the histogram. I have tried following the code in the answer to ( Understanding Gaussian Mixture Models ). However, the resulting gaussian fails to match the histogram at all. How do I get the gaussian to match the histogram? import numpy as np import cv2 import matplotlib.pyplot as plt from sklearn.mixture

Gaussian Mixture Models of an Image's Histogram

◇◆丶佛笑我妖孽 提交于 2019-11-29 19:51:38
问题 I am attempting to do automatic image segmentation of the different regions of a 2D MR image based on pixel intensity values. The first step is implementing a Gaussian Mixture Model on the image's histogram. I need to plot the resulting gaussian obtained from the score_samples method onto the histogram. I have tried following the code in the answer to (Understanding Gaussian Mixture Models). However, the resulting gaussian fails to match the histogram at all. How do I get the gaussian to

How to model a mixture of 3 Normals in PyMC?

雨燕双飞 提交于 2019-11-28 03:14:20
问题 There is a question on CrossValidated on how to use PyMC to fit two Normal distributions to data. The answer of Cam.Davidson.Pilon was to use a Bernoulli distribution to assign data to one of the two Normals: size = 10 p = Uniform( "p", 0 , 1) #this is the fraction that come from mean1 vs mean2 ber = Bernoulli( "ber", p = p, size = size) # produces 1 with proportion p. precision = Gamma('precision', alpha=0.1, beta=0.1) mean1 = Normal( "mean1", 0, 0.001 ) mean2 = Normal( "mean2", 0, 0.001 )

Any suggestions for how I can plot mixEM type data using ggplot2

匆匆过客 提交于 2019-11-27 04:34:09
I have a sample of 1m records obtained from my original data. (For your reference, you may use this dummy data that may generate approximately similar distribution b <- data.frame(matrix(rnorm(2000000, mean=c(8,17), sd=2))) c <- b[sample(nrow(b), 1000000), ] ) I believed the histogram to be a mixture of two log-normal distributions and I tried to fit the summed distributions using EM algorithm using the following code: install.packages("mixtools") lib(mixtools) #line below returns EM output of type mixEM[] for mixture of normal distributions c1 <- normalmixEM(c, lambda=NULL, mu=NULL, sigma

Understanding concept of Gaussian Mixture Models

孤人 提交于 2019-11-27 02:42:09
I'm trying to understand GMM by reading the sources available online. I have achieved clustering using K-Means and was seeing how GMM would compare to K-means. Here is what I have understood, please let me know if my concept is wrong: GMM is like KNN, in the sense that clustering is achieved in both cases. But in GMM each cluster has their own independent mean and covariance. Furthermore k-means performs hard assignments of data points to clusters whereas in GMM we get a collection of independant gaussian distributions, and for each data point we have a probability that it belongs to one of

Any suggestions for how I can plot mixEM type data using ggplot2

你。 提交于 2019-11-26 17:33:19
问题 I have a sample of 1m records obtained from my original data. (For your reference, you may use this dummy data that may generate approximately similar distribution b <- data.frame(matrix(rnorm(2000000, mean=c(8,17), sd=2))) c <- b[sample(nrow(b), 1000000), ] ) I believed the histogram to be a mixture of two log-normal distributions and I tried to fit the summed distributions using EM algorithm using the following code: install.packages("mixtools") lib(mixtools) #line below returns EM output