Rank: 3730 based on 33 downloads (last 30 days) and 1 file submitted
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William Gruner

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Company/University
University of New Mexico

Personal Profile:

Senior Research Scientist, MZA Associates Corporation, B.S. Electrical Engineering, M.S. Applied Statistics, Ph.D. Student, Medical Imaging, Department of Electrical and Computer Engineering, University of New Mexico

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Files Posted by William
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(last 30 days)
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15 Apr 2010 MANCOVAN Tools for Multivariate Analysis (Statistics Toolbox NOT Required) Author: William Gruner anova, ancova, anovan, ancovan, manova, mancova 33 6
  • 4.66667
4.7 | 3 ratings
Comments and Ratings by William View all
Updated File Comments Rating
11 Apr 2010 MANCOVAN Tools for Multivariate Analysis (Statistics Toolbox NOT Required) Author: William Gruner

Thanks for the comment! I'm sure others share your concern. We've been refactoring and expanding the feature set very rapidly as our analysis tasks become more demanding, but each new release is both validated against the Matlab Statistics Toolbox and regression tested against earlier versions to make sure that the results remain correct and that the functionality remains backward-compatible. Brace yourself, because there's another update coming soon ;-) After that, I expect things to slow down markedly. Cheers!

20 Feb 2010 Granger Causality Test Conducts a Granger Causality test using the Bayesian Information Criterion to select lag length Author: Chandler

This appears to calculate the same x and y lags regardless of the actual lags present between the two vectors. In addition, the F statistic generated by the function only appears valid for specific (small) lags. The test I used involved a simple pair of sinusoids phase-shifted to various degrees with and without a small amount of Gaussian noise.

Comments and Ratings on William's Files View all
Updated File Comment by Comments Rating
01 Dec 2013 MANCOVAN Tools for Multivariate Analysis (Statistics Toolbox NOT Required) Author: William Gruner Grievous, Right

Worked it out myself - for anyone else who might be interested the info can be displayed using the 'verbose' option - this only displays in the command window though, so I edited mLHT.m to output an additional stats table with the DoF and p values, I then get mancova.m to add F values to this to create a really condensed but highly useful second stats table...

01 Dec 2013 MANCOVAN Tools for Multivariate Analysis (Statistics Toolbox NOT Required) Author: William Gruner Grievous, Right

Great submission, I was wondering if you could tell me what the degrees of freedom are for the ANCOVA? In statistics programs like SPSS it outputs two degrees of freedom, 'treatments and error' or 'withing and between' both of which are required to report the test result. But when I run your MANCOVAN it only outputs one degree of freedom... Sorry in advance if this is a stupid question.

30 Jan 2012 MANCOVAN Tools for Multivariate Analysis (Statistics Toolbox NOT Required) Author: William Gruner Messé, Arnaud

Dear William,
Thanks for providing the MANCOVAN tools, it's a nice work!
In the mT function notes, you said:
"The tests may not always be the right ones in the context of either over-determined or sigma-restricted coding."
Could you argue this comment?
I have trouble to understand the canonical coding used... Because, this does not allow to compute all possible between groups comparisons. Is that correct?
Thanks in advance,

09 Mar 2011 MANCOVAN Tools for Multivariate Analysis (Statistics Toolbox NOT Required) Author: William Gruner Allen, Chris

17 Sep 2010 MANCOVAN Tools for Multivariate Analysis (Statistics Toolbox NOT Required) Author: William Gruner Andersen, Claus

Dear William Gruner,
Thanks for providing MANCOVA on the exchange server.
I've tried to use MANCOVA for an ANCOVA analysis, but sometimes get an error. The error occurs more frequently the more similar the two groups compared are (running Monte Carlo sim, so I impose the similarity).

The error reads:
??? Error using ==> betainc
X must be in the interval [0,1].

Error in ==> mFCDF at 44
p = betainc(a * x ./ (a * x + b), a/2, b/2);

Error in ==> mLHT at 79
p = 1 - mFCDF(G * T, q * d, D);

Error in ==> mancovan at 236
[ T(i), p(i) ] = mLHT(U, X, X0, M, M0, options);

Possibly you'd be interested in checking it out.
If need be I can also mail you the test data used.
Greetings
Claus

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