I've been working on mapping out smoke and particulate matter outcomes over zipcodes in CA, and then overlaying that data over an empty basefile of CA counties. Both shapefiles are in the same projection.
My code is similar to this:
plot(lightSmokeMap['light'], main = 'Total Number of Light Smoke Days per Zipcode')
plot(basemap['NAME'], col = NA, add = TRUE)
However, when I run this, only my initial map plots, and the basemap which is just a shapefile of CA counties does not plot at all. My confusion stems from my inclusion of the "add=TRUE" argument in my plot function not actually overlaying the shapefile. Does anyone know why this is occurring and how I can correct this?