Correlation between analytically derived metabolic flux ratios (on the y-axis)  and the projections of the data on the first eight components obtained by PCA and ICA for the [U-13C]glucose experiment with ammonium. The brightness reflects the correlation coefficient, with black and white corresponding to values of 0 and 1, respectively. For coefficients higher than 0.8, the numerical value is reported. ub, upper bound; lb, lower bound.
Zamboni and Sauer Genome Biology 2004 5:R99 doi:10.1186/gb-2004-5-12-r99