Speeding up library loading

    UweL> Ali - wrote:

    >> (1) When R tries to load a library, does it load 'everything' 

in the

    >> library at once?

    UweL> No, see ?lazyLoad

are you sure Ali is talking about *package*s.
He did use the word "library" though, and most of us (including
Uwe!) know the difference...

    >> (2) Is there any options to 'load as you go'?

    UweL> Well, this is the way R does it....

for packages yes, because of lazyloading, as Uwe mentioned above.

For libraries, (you know: the things you get from compiling and
linking C code ..), it may be a bit different.

What do you really mean, packages or libraries,
Ali?

Well, the terminology used here is a bit confusing. ?library shows 
something like 'library(package)' and that's why I used the term 
'library' for loading packages. The package does load some dll's but 
what I meant by library was actually package.

The package I am working on currently has one big R file (~ 4 Mb) and 
this causes at least 2 troubles:

(1) Things are slow:

   (a) Installation with (LazyLoad = Yes) is slow. Then when the library 
is loaded into R, the loading is slow too. So LazyLoad is of not big help.

   (b) Installation with (SaveImage = Yes) is -extremely- slow. To give 
you some idea, compiling the associated C++ code takes around 10 mins 
while saving the R images takes more than 40 mins (the package is a 
wrapper for some C++ libraries. All the R functions do is to call 
.Call). this doesn't improve the loading speed as well.
   (c) Installation with (LazyLoad = Yes) AND (SaveImage = Yes) causes 
this error:

   preparing package <package_name> for lazy loading
   make: *** [lazyload] Error 1
   *** Installation of <package_name> failed ***

   It is likely that this happens because of some memory problems.

(2) After all, when the package is loaded, not surprisingly, loads of 
memory is taken. It seems that the whole (huge) file is loaded into R at 
once and turning LazyLoad on or off doesn't make a difference when the 
package is big.