Data organization column-wise

The first thing we have to decide is whether these matrices should be organized column-wise or row-wise. The spectrum of a single sample consists of the individual absorbance values for each wavelength at which the sample was measured. Should we place this set of absorbance values into the absorbance matrix so that they comprise a column in the matrix, or should we place them into the absorbance matrix so that they comprise a row We have to make the same decision for the concentration matrix. Should the concentration values of the components of each sample be placed into the concentration matrix as a row or as a column in the matrix The decision is totally arbitrary, because we can formulate the various mathematical operations for either row-wise or column-wise data organization. But we do have to choose one or the other. Since Murphy established his laws long before chemometricians came on the scene, it should be no surprise that both conventions are commonly employed throughout the literature ... 

Column-Wise Data Organization for MLR and PCR Data Absorbance Matrix... 

Using column-wise organization, an absorbance matrix holds the spectral data. Each spectrum is placed into the absorbance matrix as a column vector ... 

A data matrix with column-wise organization is easily converted to row-wise organization by taking its matrix transpose, and vice versa. If you are not familiar with the matrix transpose operation, please refer to the discussion in Appendix A. 

To (hopefully) help keep things simple, we will organize all of our data into column-wise matrices. Later on, when we explore Partial Least-Squares (PLS), we will have to remember that the PLS convention expects data to be organized row-wise. This isn t a great problem since one convention is merely the matrix transpose of the other. Nonetheless, it is one more thing we have to remember. 

The product from Step 2 (2.06 mmol) was dissolved in 10 ml THE and added drop wise to a stirred suspension of NaH (2.27 mmol) in 5 ml THE at ambient temperature. After 15 minutes, the product from Step 1 (2.1 mmol) dissolved in 5 ml THE was added, the mixture stirred for several hours and was then quenched with 1 ml water. The organic phase was evaporated and the residue purified by column chromatography on silica with CH2Cl2/methyl alcohol, 95 5, yielding a Z/E geometric isomer ratio of 76 24, respectively. The desired Z-isomer was isolated by re-crystallization, mp = 189-190 °C. H-NMR and mass spectrum data supplied. 

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