Community Profile

# Jeff Miller

##### Last seen: Today
314 total contributions since 2013

View details...

Contributions in
View by

Help with finding the average correlation coefficient between a matrix value and its surrounding neighbors?
A correlation isn't designed to measure the similarity between two isolated values, like your given (i,j) element and each of it...

7 days ago | 1

calculate a P value using a permutation test
This contribution on file exchange looks like it will do what you want.

13 days ago | 0

Looping through a large questionnaire set, creating new tables
I hate to say this, but it might be easiest to do a lot of the work in Excel. Note that the data in your screenshot are represe...

17 days ago | 0

| accepted

Generate correlated random variables in a wider domain
It looks like 3.15 and 3.4 are the maximum values in the generalized extreme value and pareto distributions with the parameters ...

22 days ago | 0

Weibull fit to interval censored data
You can do this with Cupid. Here is an example: % Generate some truncated Weibull data just to have an example % of some data ...

1 month ago | 0

Efficient code for obtaining the probability of X or less, when the PDF is known, but the CDF cannot be expressed precisely
Unless you have closed form or a good approximation to the CDF, it seems like your only option is to integrate the PDF with MATL...

2 months ago | 1

Compare Betas from two different GLMS
You might compare confidence intervals. For example, the estimated value for evidence control is .62033. Compute an approximate...

2 months ago | 0

How can I simulate data from two different distribution using Copulas?
OK, then I think you are almost there. You have the data X, Y, and rhoXY. Start by estimating the parameters for your gamma an...

2 months ago | 0

| accepted

How can I simulate data from two different distribution using Copulas?
The question is a little confusing because the U values are from 0 to 1 but the Q values aren't. Q(1,:) looks like a gamma but ...

2 months ago | 0

seed for Monte Carlo
It sounds like you would be better off not to set the seed at all--just use MATLAB's default seed, which is different every time...

2 months ago | 0

Running repeated anova on all elements of large matrix
If you really just want the F value, you can probably get it much faster by looking up the formulas for the one-factor within-Ss...

2 months ago | 0

| accepted

Generate column of random numbers that change slowly from row to row
You might generate the random points as you have but then smooth them with the smooth or filter function, e.g., sprob = zeros(s...

2 months ago | 0

| accepted

What the two columns represnt when i generate a multivarite normal random numbers
The two columns represent the two variables measured for each case, and the N rows represent the N randomly selected cases from ...

2 months ago | 0

| accepted

Fitting a non-linear model to my data
Take logs and use multiple regression. That is, fit the model log(y) = a log(x1) + b log(x2) etc This will give you the best ...

2 months ago | 1

| accepted

Integrating a t-test into a function how-to
Put in a breakpoint at the ttest2 line and check the inputs x and y that you are passing. These must not be what ttest2 expects...

2 months ago | 0

Fit Gaussian mixture model with weighted observations
It's not exactly clear (to me either) what it means to weight the different observations in this context, but maybe you have som...

2 months ago | 0

Convolution of two different pdf (uniform and normal distribution)
The Cupid toolbox will do this. For example, u = Uniform(0,100); n = Normal(100,10); % 2nd parameter is sigma, not sigma^2 c...

2 months ago | 0

| accepted

Within- & between-subjects in 'anovan'
I also found the lack of between/within terminology a bit daunting. With respect to your first question, here is an example tha...

2 months ago | 1

Question

any trick to stop fminsearch early?
I am using fminsearch to minimize an error score in fitting a model to many, many data sets. Often, the error score gets close ...

2 months ago | 2 answers | 0

### 2

How can I introduce a known autocovariance to a lognormal process
You should be able to do it by generating your sequence one element at a time, if you can't find a canned routine that will do i...

2 months ago | 0

How to calculate the conditional proabability?

3 months ago | 0

How to find the maximum of a normalized fit of a histogram
Try this: dist = Histogram(2) maxnorm = max(dist.YData); line([min(dist.XData) max(dist.XData)], [maxnorm maxnorm], 'LineWidt...

3 months ago | 0

Extreme Value Distribution y-axis not same with Histogram
histogram(total,'normalization','pdf');

3 months ago | 0

Multiple univariate or multivariate analysis?
No, that's probably not the right way to go. The problem with this approach is that you have a 5% chance of making a type 1 err...

3 months ago | 0

How to calculate the P-value using chi-square and degrees of freedom
p = 1 - chi2cdf(x,df)

3 months ago | 0

Is there a way to do a multi normal distribution fitting in Matlab?
The sigma isn't really off. GMModel.Sigma is variance = sigma^2

3 months ago | 0

| accepted

Log-Normal fit of histogram
fitdist wants the x values that were tabulated to get the histogram, not the bin counts. From your histogram, it looks like you...

3 months ago | 0

Parameter estimation - estimate integers only
One way to do this is to write your objective function to return an error function that is linearly interpolated between two int...

3 months ago | 0