RTE: source functions

Module mo_source_functions in the RTE library provides class ty_source_func_lw to encapsulate Planck source functions computed for each (spectral) g-point at layer, level, and surface temperatures. (The module also contains the class ty_source_func_sw but this is not currently used). The classes extend ty_optical_props and inherit those initialization and inquiry methods. Assuming a declaration of the form type(ty_source_func_lw):: src_lw the class is used as follows:

Allocating memory

err_msg = src_lw%alloc(ncol, nlay) provides memory for a problem with ncol columns and nlay layers. If src_lw has not been previously-initialzed the routine fails and reports an error.

err_msg = src_lw%alloc(ncol, nlay, ops), where ops is a previously-initialized variable of ty_optical_props, combines initialization and allocation, copying the spectral discretization from ops to src_lw.

Extracting a subset of columns

err_msg = src_lw%subset(ncol, nlay, subset), where subset is a variable of ty_source_func_lw, extracts columns start to start+n-1 from the class into variable subset.

call src_lw%finalize() returns the variable to its un-initialzed state.