[R] Stacked Bar Plot With Two Dependent Variables

Hi All, I need to construct a stacked bar plot with two independent (x) variables, where the stacking is x1 and the x-axis label is x2. Can someone help out with the code for this or provide a reference/example? Thank you, J -- View this message in context:

[R] Need help with lmer model specification syntax for nested mixed model

I haven't been able to fully make sense of the conflicting online information about whether and how to specify nesting structure for a nested, mixed model. I'll describe my experiment and hopefully somebody who knows lme4 well can help. We're measuring the fluorescence intensity of brain slices