minor updates to readme

.gitignore

@@ -134,3 +134,5 @@ benchmarks/*.png
 # cffi stuff
 *.pc
 cpdfflow.c
+# example executables
+example

capi/README.md

@@ -7,11 +7,9 @@ This repository contains a C library to access PDFFlow from programming language
 
 Make sure you have installed the `pdfflow` module in Python, then in order to install proceed with the usual cmake steps:
 ```bash
-mkdir build
-cd build
-cmake .. -DCMAKE_INSTALL_PREFIX=<your install prefix>
-make
-make install
+cmake -S . -B build -DCMAKE_INSTALL_PREFIX=<your install prefix>
+cmake --build build
+cmake --install build
 ```
 
 ## Usage
@@ -23,4 +21,11 @@ pkg-config pdfflow --cflags
 pkg-config pdfflow --libs
 ```
 
+If you installed to a non-standard location, you need to set up the `PKG_CONFIG_PATH` and `LD_LIBRARY_PATH`, e.g.:
+```bash
+export PKG_CONFIG_PATH=${VIRTUAL_ENV}/lib/pkgconfig/:${PKG_CONFIG_PATH}:
+export LD_LIBRARY_PATH=${VIRTUAL_ENV}/lib/:${LD_LIBRARY_PATH}:
+```
+
+
 Sample programs using this library are provided in the `capi/examples/` directory.

capi/examples/example.c

@@ -4,7 +4,7 @@
 
 int main() {
     // load pdf
-    mkpdf("NNPDF31_nlo_as_0118/0", "/usr/share/lhapdf/LHAPDF/");
+    mkpdf("NNPDF40_nnlo_as_01180/0", "/usr/share/lhapdf/LHAPDF/");
 
     // test xfxq2 and alphasq2
     int pid[] = {-5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5};

capi/examples/fortran/example.f90

@@ -10,7 +10,7 @@ program example
    real(dp) :: alpha_s, q2(0:1), x(0:1), xfx(0:11)
    real(dp) :: q2_vectorized(0:2), as_vectorized(0:2)
 
-   character(kind=c_char, len=21) :: ss = "NNPDF31_nlo_as_0118/0"
+   character(kind=c_char, len=23) :: ss = "NNPDF40_nnlo_as_01180/0"
    character(kind=c_char, len=24) :: pp = "/usr/share/lhapdf/LHAPDF/"
 
    call mkPDF(ss, pp)

setup.cfg

@@ -30,7 +30,7 @@ install_requires =
 where = src
 
 [options.extras_require]
-capi = ciffi
+capi = cffi
 docs =
     sphinx_rtd_theme
     recommonmark

src/pdfflow/pflow.py

@@ -108,6 +108,7 @@ def mkPDF(fname, dirname=None):
     ----------
         fname: str
             PDF name and member in the format '<set_name>/<set member number>'
+            If the set number is not given, assume member 0
         dirname: str
             LHAPDF datadir, if None will try to guess from LHAPDF
 
@@ -116,8 +117,12 @@ def mkPDF(fname, dirname=None):
         PDF: pdfflow.PDF
             instantiated member of the PDF class
     """
-    fname_sp, member = fname.split("/")
-    member = int(member)
+    try:
+        fname_sp, member = fname.split("/")
+        member = int(member)
+    except ValueError:
+        fname_sp = fname
+        member = 0
     return mkPDFs(fname_sp, [member], dirname=dirname)