The Long, Complicated, Tedious, and Difficult Route to Principal Components: Part V (Or, "When you're through reading this set you'll know why it's always done with matrices.") Oct 1, 2008 By: Jerome Workman, Jr., Howard Mark

For a system of homogeneous equations to have a solution other than the trivial solution, the determinant of the system of equations must be zero.

The Long, Complicated, Tedious, and Difficult Route to Principal Components: Part III (Or, "When you're through reading this set you'll know why it's always done with matrices.") May 1, 2008 By: Howard Mark, Jerome Workman, Jr.

Howard Mark and Jerome Workman, Jr. continue their discussion of the derivation of the principal component algorithm using elementary algebra.

The Long, Complicated, Tedious, and Difficult Route to Principal Components: Part II Feb 1, 2008 By: Howard Mark, Jerome Workman, Jr.

Howard Mark and Jerome Workman, Jr. continue their discussion of the derivation of the principal component algorithm using elementary algebra.

The Long, Complicated, Tedious, and Difficult Route to Principal Components: Part I Sep 1, 2007 By: Jerome Workman, Jr., Howard Mark

In this month's installment, columnists Howard Mark and Jerome Workman, Jr. present the derivation of the principal component algorithm using elementary algebra.

Addendum to Chemometrics in Spectroscopy Corrections to Analysis of Noise: Part II Jun 1, 2007 By: Jerome Workman, Jr., Howard Mark

This column is the continuation of a series (1-5) dealing with the rigorous derivation of the expressions relating the effect of instrument (and other) noise to its effects on the spectra we observe. Our first column in this series was an overview. While subsequent columns dealt with other types of noise sources, the ones listed analyzed the effect of noise on spectra when the noise is constant detector noise (that is, noise that is independent of the strength of the optical signal). Inasmuch as we are dealing with a continuous series of columns, on this branch in the thread of the discussion, we again continue the equation numbering and use of symbols as though there were no break. The immediately previous column (5) was the first part of this set of updates of the original columns.

Limitations in Analytical Accuracy, Part II: Theories to Describe the Limits in Analytical Accuracy and Comparing Test Results for Analytical Uncertainty Feb 1, 2007 By: Jerome Workman, Jr., Howard Mark

In the second part of this series, columnists Jerome Workman, Jr. and Howard Mark continue their discussion of the limitations of analytical accuracy and uncertainty.

Connecting Chemometrics to Statistics - Part II: The Statistics Side Jun 1, 2006 By: Howard Mark, Jerome Workman, Jr.

In this month's installment of "Chemometrics in Spectroscopy," the authors again explore that vital link between statistics and chemometrics, this time with an emphasis on the statistics side.

Connecting Chemometrics to Statistics - Part I: The ChemometricsSide May 1, 2006 By: Howard Mark, Jerome Workman, Jr.

In this month's installment of "Chemometrics in Spectroscopy," the authors explore that vital link between statistics and chemometrics, with an emphasis on the chemometrics side.

At this point in our series dealing with linearity, we have determined that the data under investigation do indeed show a statistically significant amount of nonlinearity, and we have developed a way of characterizing that nonlinearity. Our task now is to come up with a way to quantify the amount of nonlinearity, independent of the scale of either variable, and even independent of the data itself.