From: Rui on
Why does this work this way?
lolo = - Table[i j, {i, 1, 7}, {j, 1, 128}] (* is negative *)
ArrayPlot[lolo, ColorFunction -> "TemperatureMap", AspectRatio -> 1/
GoldenRatio, MaxPlotPoints -> 128]
shows with the colors right (and higher MaxPlotPoints too), but

ArrayPlot[lolo, ColorFunction -> "TemperatureMap", AspectRatio -> 1/
GoldenRatio, MaxPlotPoints -> 127] shows them with the ColorFunction
inverted

Thankx