Add a Layer to a Next Generation Clustered Heat Map (NGCHM) and return the extended CHM. A CHM requires at least one Layer. The first layer added to a NGCHM becomes the primary layer. The second layer added to a NGCHM, if any, becomes the secondary (flicker) layer. Currently at most two layers can be added to a NGCHM.
Usage
chmAddLayer(chm, layer)
# S4 method for class 'ngchm,ngchmLayer'
chmAddLayer(chm, layer)
# S4 method for class 'ngchm,matrix'
chmAddLayer(chm, layer)