How do I access a pdf file stored in R.raw in the android SDK?

I think I'm missing some information for the pdf file to appear in my app. I used the following line of code inside the OnCreate method:

        PDFView novo = (PDFView)findViewById(R.id.pdfView);
        novo.fromAsset("arquivo");

But still, the PDF does not appear when I put it to run the app. What is missing? I think this string has to be referenced somewhere is not it? How do I do this?