SDALG   Constructor of a custom algorithm object

   ALG=SDALG(FUNCNAME)
   OUT=SDALG(ALG,DATA)

   alg=sdalg(mfilename) % instantiate inside algorithm function

 DESCRIPTION
 SDALG implements custom algorithms defined in a single function.  See
 SDA_PCA_CLF for example. SDALG creates an object attached to a function
 FUNCNAME. ALG contains parameters needed for its training and for
 execution.

 SEE ALSO
 SDA_PCA_CLF, SDA_PCA_CLF_ROC