Helpers for pretty printing

There are a number of functions in DB-ALLe, the idba_spiega group of functions, that are not needed for normal processing but can be useful to improve the presentation of data to users.

All these function take a number of parameters and a string, and they store a proper description of the values into the string.

The functions are:

idba_spiegal(handle,ltype,l1,l2,string)

Describes a level. For example, idba_spiegal(handle,106,10,20,string) will store in string something like: ``Layer between 10hm and 20hm above ground``.

idba_spiegat(handle,ptype,p1,p2,string)

Describes a time range. For example, idba_spiegat(handle,3,0,600,string) will store in string something like: ``Average between reference time+0s to reference time+600s``.

idba_spiegab(handle,varcode,value,string)

Describe a value. For example, idba_spiegab(handle,B12001,280,string) will store in string something like: ``280 (K) TEMPERATURE/DRY-BULB TEMPERATURE``.