Plotting functions to plot all NAs

PlotEquiMap() and PlotLayout() cannot plot the array with all NAs. They return errors.

asd <- array(NA, dim = c(lat = 181, lon = 360))
PlotEquiMap(asd, lon = 0:359, lat = -90:90, filled.continents = F)
Error in ColorBar(brks, cols, FALSE, subsampleg, bar_limits, var_limits,  : 
  Parameter 'var_limits' must not contain infinite values.

And the error from PlotLayout() can be seen in auto-s2s#49. Alba provided a workaround for PlotLayout() (see auto-s2s#49 (comment 212966)).

The functions should plot colNA for all NAs array.