Thanks a lot for your comments. In fact I had an idea that maybe it is a
pointer that is transferred after Simon's yesterday's commnent. So
generally I should always allocVector for imgSize before passing it and
just let the garbage collector to clean them afterwards if I understand
right.
Best regards
Oleg
Dr Oleg Sklyar
European Bioinformatics Institute
Wellcome Trust Genome Campus
Hinxton, Cambridge, CB10 1SD
England
phone/fax +44(0)1223 49 4478/4468
e-mail [EMAIL PROTECTED]
Prof Brian Ripley wrote:
On Thu, 17 Mar 2005, Oleg Sklyar wrote:
Dear Simon,
you gave us only a fragment of your code, so I can only guess what the
problem is:
What is imgSize? The behavior you describe seems as if you re-using the
imgSize SEXP in all elements.
AFAIR in your case setAttrib doesn't copy the value, so you need to
do so
yourself (or alloc new dim array
for each element).
Sorry, it is always a tradeoff - either to explain or put a
relatively large code, which also uses non-standard libraries making
the code difficult to read. imgSize values are reset in between: see
the full code below. The SEXP pointer imgSize stays in tact, that's
true, but its values are changed (the problem is, they are always the
last in the row). I.e. if I have 3 images 40x20, 200x100 and 150x75 I
will get three matrices of 150x75, but if I omit setAtrib and return
vectors I get vectors of different length.
So, as Simon says, you need to create separate objects for the
dimensions of each matrix, not share the object. It is the object
pointed to by imgSize you have attached as the dimensions, not the
values.
BTW, setAttrib(element, R_DimSymbol, imgSize) just calls
dimgets(element, imgSize), so I would have used the latter directly.
I believe you do not have three matrices of 150x75, rather a vector of
length 40*20 with an inconsistent dim attribute of c(150, 75), etc.
Oleg
SEXP load2DImages(SEXP fileNames) {
int nFiles = LENGTH(fileNames);
std::cout << "Loading " << nFiles << " files..." << std::endl;
// SEXP result = allocList(nFiles);
SEXP result = allocVector(VECSXP, nFiles);
PROTECT(result);
SEXP imgSize = allocVector(INTSXP, 2);
PROTECT(imgSize);
TRGB2DImage::Pointer image;
TRGB2DReader::Pointer reader = TRGB2DReader::New();
TRGB2DImage::SizeType size; TRGB2DImage::IndexType pixIndex;
for (int i = 0; i < nFiles; i++) {
try {
char *filename = CHAR(asChar(VECTOR_ELT(fileNames, i)));
std::cout << std::endl << "Loading image file " << filename
<< "... ";
reader->SetFileName(filename);
reader->Update();
image = reader->GetOutput();
} catch(...) {
std::cout << "failed!";
continue;
}
std::cout << std::endl;
size = image->GetLargestPossibleRegion().GetSize();
INTEGER(imgSize)[0] = size[1];
INTEGER(imgSize)[1] = size[0];
std::cout << size[0] << " x " << size[1] << std::endl;
SET_VECTOR_ELT(result, i, allocVector(INTSXP, size[0] * size[1]));
SEXP element = VECTOR_ELT(result, i);
for (int ix = 0; ix < size[0]; ix++) {
pixIndex[0] = ix;
for (int iy = 0; iy < size[1]; iy++) {
pixIndex[1] = iy;
INTEGER(element)[size[1] * ix + iy] =
getIntRGBColour(image->GetPixel(pixIndex));
}
}
setAttrib(element, R_DimSymbol, imgSize);
}
UNPROTECT(2);
if (nFiles == 1)
return VECTOR_ELT(result, 0);
else
return result;
}
Dr Oleg Sklyar
European Bioinformatics Institute
Wellcome Trust Genome Campus
Hinxton, Cambridge, CB10 1SD
England
phone/fax +44(0)1223 49 4478/4468
e-mail [EMAIL PROTECTED]
Simon Urbanek wrote:
Oleg,
you gave us only a fragment of your code, so I can only guess what
the problem is:
On Mar 16, 2005, at 12:40 PM, Oleg Sklyar wrote:
// converting element into a matrix
setAttrib(element, R_DimSymbol, imgSize);
What is imgSize? The behavior you describe seems as if you re-using
the imgSize SEXP in all elements. AFAIR in your case setAttrib
doesn't copy the value, so you need to do so yourself (or alloc new
dim array for each element).
Cheers,
Simon
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