# Fractals Miner

**08**
*Tuesday*
May 2018

**08**
*Tuesday*
May 2018

Advertisements

**24**
*Tuesday*
Apr 2018

in

**Tags**

Ancient Mathematicians, Famous Mathematicians, Math History, Mathematician Biographies, Mathematics, minerazzi, Modern Mathematicians

Math Bios is a new miner available at

http://www.minerazzi.com/mathbios

Find biographies of famous mathematicians from ancient to modern times.

Interested in the life of Euler, Fermat, Poincare, Blackwell, and other great mathematicians? Want to build a curated collection about math people from the ancient and modern times? This is the place to start.

A great tool for math history researchers and students in general.

**22**
*Sunday*
Apr 2018

**Tags**

Algorithms, Linear Algebra, Mathematics, Matrices, Polynomial Regression, Regression, tools, tutorials

If you are a chemist, biodesigner, or a researcher working in other fields, eventually you may need to fit a paired data set to a polynomial regression model. You could use software to do that, or build your own solution. This tutorial is aimed at those interested in the latter. Access it now at

http://www.minerazzi.com/tutorials/polynomial-regression-tutorial.pdf

Three different methods for implementing polynomial regression are described. Teachers and students might benefit from the tutorial since the calculations can be done with a spreadsheet software like Excel, by writing a computer program, or with a programmable calculator.

**03**
*Tuesday*
Apr 2018

**Tags**

Algorithms, Chaos, evolutionary patterns, fractals, manglar, Mathematics, Nonlinear Dynamics, plants evolution, tools

Do you see the algorithm behind this image? Hint: It corresponds to Manglar, an upcoming tool I’m building for simulating the growth of patterns. I’m still testing it.

Manglar. Coming Soon.

**15**
*Tuesday*
Aug 2017

**Tags**

Puerto Rico Statistics Institute (Instituto de Estadísticas de Puerto Rico) has a nice introductory manual on R, written by Dr. Orville M. Disdier. Check it out at

http://estadisticas.pr/iepr/LinkClick.aspx?fileticket=p71ePCZXuYM%3d&tabid=100

or get access by visiting

http://estadisticas.pr/iepr/Academias.aspx

BTW, there is a new version of the site which at the time of writing is still in beta at

**17**
*Monday*
Jul 2017

**Tags**

Correlation Coefficients, Data Mining, Mathematics, Pearson Correlation, Spearman Correlation, statistics, tutorials

This is Part 2 of a tutorial series on the nonadditivity of correlation coefficients. This time we discuss Fisher *r*-to-*Z* and *Z*-to-*r* transformations and the risks of arbitrarily implementing these.

Misusing the transformations can have a detrimental impact on significance testing, confidence intervals, reported standard errors of correlations, and meta-analysis.

The tutorial is available at

http://www.minerazzi.com/tutorials/nonadditivity-correlations-part-2.pdf

**11**
*Tuesday*
Jul 2017

This is a new Minerazzi tool available now at

http://www.minerazzi.com/tools/regression-correlation/calculator.php

The tool does simple linear regression and correlation analyses, computing Spearman and Pearson correlation coefficients and other relevant statistics.

The companion default example was intentionally selected to illustrate that for rank data free from ties, Spearman and Pearson correlation coefficients are the same thing.

**05**
*Wednesday*
Jul 2017

**Tags**

Causality, Causation, Determinism, Mathematics, miner, minerazzi, statistics

This is a new miner, available now at

http://www.minerazzi.com/causality/

Find resources or build curated collections about causality, causation, and determinism.

**03**
*Monday*
Jul 2017

This is Part 1 of a tutorial series on the nonadditivity of correlation coefficients. We demonstrate why it is not possible to arithmetically add, subtract, and average Pearson’s *r* or Spearman’s *r _{s}*.

The article is available at

http://minerazzi.com/tutorials/nonadditivity-correlations-part-1.pdf

07-04-2017 update: In page 1 the line for the *Beta _{1 }*should read “is the slope of a simple linear regression model”. My fault. Fixed today along with few other nuances.

Enjoy it!

**28**
*Wednesday*
Jun 2017

This is a new Minerazzi tool, available now at

http://www.minerazzi.com/tools/t-p-effect-size/estimator.php.

This tool estimates t-scores from p-values and vice versa for a given number of degrees of freedom υ. Just enter a (t,υ) or (p,υ) pair and this tool will solve for the missing term.

The tool also estimates the statistics that one would obtain if the computed estimates correspond to a set of paired variables (x, y), or to effect sizes from any two samples of same sizes (n1 and n2); i.e. samples with same degrees of freedom (υ1 and υ2).

The tool’s page lists some interesting exercises and good references for effect size conversions and meta-analysis in general. Enjoy it!