SUMMARY OF EXPLAINED VARIANCE For each principal component region, variances are calculated in this script. The maximum available period is the period in which all the MBH98 sites are available as summarized here. The overlap period is the common period between the available period and the MBH period. Total variance is calculated for both periods. In the TexasOklahoma case, the overlap period and the maximum available period are close and there is little difference in this quantity. The "recalculated" principal components and eigenvectors are calculated using a standard Ralgorithm; these are expanded and the unexplained variance calculated. For MBH, the eigenvectors are calculated to maximize explained variance using the qrfunction in R. The explained variance using MBH principal components is then calculated. The extremely low explained variance for the MBH TexasMexico principal components  5% for 9 principal components and only 20 sites  was the stimulus for the present analysis. If the collation errors are fixed in this series, the explained variance increases to 41%, but in no case is the MBH calculation correct.
