[R] Linking to C type short?

Spencer Graves spencer.graves at structuremonitoring.com
Thu Jul 26 22:22:22 CEST 2012


Hello, All:


       What references exist on how to link to C?


       I'm familiar with sections 5.2 and 5.6 of the "Writing R 
Extension" manual plus chapter 6 of Venables and Ripley (2000) S 
Programming (Springer).  From these, I get the following:


R storage mode   C type
logical          int *
integer          int *
double           double *
complex          Rcomplex *
character        char **
raw              unsigned char *
list             SEXP *
R object         SEXP


       "integer" and "int" are 32 bits.  If I understand correctly, 
"short" has only 16 bits = 2 bytes.


       Should I define any "short" vector in C as a matrix with 2 rows 
of type either "raw" or "char"?


       Thanks,
       Spencer


p.s.  I need this to link to lossless JPEG code obtained from 
"ftp.cs.cornell.edu/pub/multimed/ljpg.tar.Z"


-- 
Spencer Graves, PE, PhD
President and Chief Technology Officer
Structure Inspection and Monitoring, Inc.
751 Emerson Ct.
San José, CA 95126
ph:  408-655-4567
web:  www.structuremonitoring.com



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