Hi all Two questions: 1. I note that help for the postscript device claims "The postscript produced by R is EPS (Encapsulated PostScript) compatible...". It does not say it is EPS *compliant*. Indeed, the EPS produced by R includes a \showpage command which I believe (not that I'm an expert!) non-standard EPS. My question: Is there any reason why it is EPS compatible, but not compliant? (I ask because the \showpage caused me a minor trouble once.) 2. R and S-Plus restrict the available combinations of link functions and response distributions when using glm. The combinations allowed are certainly sensible, but what is the logic for disallowing other combinations (eg identity link only is allowed for the gaussian family)? I also know there are ways around it; I was just wondering about the reasoning. Thanks, P. -- Dr Peter Dunn (USQ CRICOS No. 00244B) Web: http://www.sci.usq.edu.au/staff/dunn Email: dunn @ usq.edu.au Opinions expressed are mine, not those of USQ. Obviously...
Peter Dunn wrote:> 1. I note that help for the postscript device claims "The > postscript produced by R is EPS (Encapsulated PostScript) > compatible...". It does not say it is EPS *compliant*. > Indeed, the EPS produced by R includes a \showpage command > which I believe (not that I'm an expert!) non-standard EPS. > My question: Is there any reason why it is EPS compatible, > but not compliant? (I ask because the \showpage caused me > a minor trouble once.)Adobe's tech documents are here: http://partners.adobe.com/asn/developer/technotes/postscript.html and says "The showpage operator is permitted in EPS files because it is present in so many PostScript language files. Therefore, it is reasonable for an EPS file to use the showpage operator, although it is not necessary if the EPS file will only be imported into another document. The application importing the EPS file is responsible for redefining showpage." So it seems that any problem you had with showpage was possibly the importing application's fault. I've just realised I've been hacking PS files for 15 years now... Barry Rowlingson Maths and Stats Lancaster University Lancaster, UK
... and one answer ... On 02-Apr-03 Peter Dunn wrote:> Hi all > > Two questions: > > 1. I note that help for the postscript device claims "The > postscript produced by R is EPS (Encapsulated PostScript) > compatible...". It does not say it is EPS *compliant*. > Indeed, the EPS produced by R includes a \showpage command > which I believe (not that I'm an expert!) non-standard EPS. > My question: Is there any reason why it is EPS compatible, > but not compliant? (I ask because the \showpage caused me > a minor trouble once.)Nothing whatever wrong with this, and it is perfectly standard and "compliant" and indeed is covered in the PostScript Language Reference Manual. Using 'showpage' allows the file to be displayed directly on any PS device, while the file can be embedded in another document PROVIDED the embedding PS code redefines 'showpage' to be null (i.e. /showpage {} def) for the duration of the wrapper. Some document-generating software, however, can be sloppy about this, in which case you will indeed have trouble. But that is the fault of the software, not of the fact that 'showpage' is present in the file. Ted. -------------------------------------------------------------------- E-Mail: (Ted Harding) <Ted.Harding at nessie.mcc.ac.uk> Fax-to-email: +44 (0)870 167 1972 Date: 03-Apr-03 Time: 14:03:33 ------------------------------ XFMail ------------------------------