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Questions tagged [goodness-of-fit]

Goodness of fit tests indicate whether or not it is reasonable to assume that a random sample comes from a specific distribution.

"They are a form of hypothesis testing where the null and alternative hypotheses are:

H0: Sample data come from the stated distribution
HA: Sample data do not come from the stated distribution

These tests are sometimes called *omnibus tests."

Reference:

Ricci, V. (2005). Fitting distributions with R. page 16.

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Regarding chisq.test (x, p) function for goodness of fit, how does R tell the degree of freedom of chi-square?

If I test x against a Poisson hypothesis, then I use mean(x) as lambda to calculate p so df = k - 2; if against a Normal hypothesis, then I use mean(x) and var(x) to calculate p so df = k - 3. How can R return a chisq value without knowing the df…
limestreetlab
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Chi-Square Test of Independence in r

I have a technical question related to my df structure. It looks like this: Month District Age Gender Education Disability Religion Occupation JobSeekers GMI 1 2020-01 Dan U17 Male None None …
Moshep
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How do I test the data to fit to the Poisson distribution with goodfit?

I have a data set with car arrivals per minute. I drew a histogram and fit to the Poisson distribution with the following R codes. #Aladdin Arrivals Datast <- read.csv("Vehiclecount.csv", header = T, sep=";", dec=",") hist(Datast$Arrival,…
Fatih Güneş
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Error: $ operator not defined for this S4 class while running hoslem.test

I'm working on an optimization of a logistic regression model made with glm, the optimization is a lasso regression using glmnet. I want to compare both models using the output of a Hosmer Lemeshow test and I get this output. For the glm I get > hl…
Adán Azuz
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Vuong & Clarke test using output from mle in R?

I want to test which one of two non-nested models that I fit using stats4::mle in R provides a better fit using the Vuong and the Clarke test. Vuong (Econometrica, 1989): https://www.jstor.org/stable/1912557?seq=1#metadata_info_tab_contents Clarke…
shofla
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How to calculate the R square for the raster data (.tiff) in the python

]2 I want to plot the regression line and calculate the regression coefficient. Along with that the R square/Goodness of fit. I have determined the regression line on the curve and calculated the coefficient of that regression line but not be able…
Ronak Jain
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Problem with Goodness-Of-Fit tests for objects of class kppm in spatstat version 1.61-0

I am using different Goodness of fit tests for objects of class kppm. The goodness of fit tests in the attached code worked fine in version 1.59-0 of spatstat, but in the most recent version (1.61-0 and 1.61-0.019), there is an error related to…
Yeltsin Parmenio Vega Niño
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Discrete Kolmogorov-Smirnov testing: getting wrong value when using rpy2 compared to pure R

I am trying to use the dgof module from R, in Python 3 via rpy2. I use it inside python as so: # import rpy2's package module import rpy2.robjects.packages as rpackages # Import R's utility package utils = rpackages.importr('utils') # Select a…
Astrid
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NbClust nstart and iter.max options

I am interested in using the NbClust package to try and evaluate various classification solutions. I know that NbClust has methods to implement such algorithms but these are limited. In particular NBClust does not allow multiple starts or an…
Stephen Clark
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Performing Kolmogorov-Smirnov test for goodness of fit - scipy

I am trying to perform KS test goodness of fit for my data and estimated distribution. Plot is like this The code I am using and the results are as follows: sp.stats.kstest(df['col'], 'norm', args = (mean, sd), N =…
Bonzogondo
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Quick way of finding a name of a variable with lowest component value

I have a function fitting a distribution and returning a vector consisting of distribution name, mean, sd, etc. I'm testing few distributions but I can't rely on gofstat() because it goes mad when there are too many zeros to consider. Therefore I…
ErrHuman
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in R, does a "goodness of fit" value exist for vegan's CCA, similar to NMDS's "stress" value?

I would like to know if there is a way to extract something similar to the metaMDS "stress" value from a vegan cca object? I've tried the goodness.cca function and its…
crazysantaclaus
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Posterior Predictive Check in JAGS - Dimension Mismatch Error

I'm wondering if someone can help me troubleshoot here. I'd like to do a goodness of fit assessment for the poisson log normal model below (this is just the simple test model). When I comment out the fit <- sum(resi[]) and fit.new <- sum(resi.new[])…
Michelle
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Computing correlations and performing goodness of fit for prng testing

I'm following along with a description of a test for pseudo-random number generators, and attempting to implement the test in C. There's one thing I'm hung up on though. The text in question is as follows: Applies a correlation test on the Hamming…
Davigor
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Ranks and identification of elements in r

I have two vectors with different elements, say x=c(1,3,4) , y= c(2,9) I want a vector of ranges that identifies me the elements of vector x with 1 and those of y with 0, ie (1,2,3,4,9) -----> (1,0,1,1,0) How could you get the vector of zeros and…
albert
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