propagating vec to xfxq2

capi/examples/example.c

@@ -7,9 +7,12 @@ int main() {
     mkpdf("NNPDF31_nlo_as_0118/0", "/usr/share/lhapdf/LHAPDF/");
 
     // test xfxq2 and alphasq2
-    const double x = 0.1, q2 = 1.65;
-    for (int fl=-5; fl <=5; fl++)
-        printf("flv=%d - xfx = %f\n", fl, xfxq2(fl, x, q2));
+    int pid[] = {-5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5};
+    double xs[] = {0.1};
+    double q2s[] = {1.65};
+    double *xf_vectorized = xfxq2(pid, 11, xs, 1, q2s, 1);
+    for (int fl = 0; fl < 11; fl++)
+        printf("flv=%d - xfx = %f\n", fl-5, xf_vectorized[fl]);
 
     double q2_vectorized[] = {1.65, 10.65};
     double* as_vectorized = alphasq2(q2_vectorized, 2);

capi/src/pdfflow/pdfflow.h

@@ -4,6 +4,6 @@
 
 extern void mkpdf(const char *fname, const char * dirname);
 
-extern double xfxq2(int pid, double x, double q2);
+extern double *xfxq2(int *pid, int n, double *x, int m, double *q2, int o);
 
 extern double *alphasq2(double *q2, int n);

capi/src/wrapper.py

@@ -15,15 +15,19 @@ def mkpdf(fname, dirname):
 
 
 @ffi.def_extern()
-def xfxq2(pid, x, q2):
-    """Returns the xfxQ2 value for a given PID at specific x and q2."""
+def xfxq2(pid, n, x, m, q2, o):
+    """Returns the xfxQ2 value for arrays of PID, x and q2 values."""
     global pdf
-    return pdf.xfxQ2([pid], [x], [q2])
+    pid_numpy = np.frombuffer(ffi.buffer(pid, n*ffi.sizeof('int')), dtype='int32')
+    x_numpy = np.frombuffer(ffi.buffer(x, m*ffi.sizeof('double')), dtype='double')
+    q2_numpy = np.frombuffer(ffi.buffer(q2, o*ffi.sizeof('double')), dtype='double')
+    ret = pdf.xfxQ2(pid_numpy, x_numpy, q2_numpy).numpy()
+    return ffi.cast("double*", ffi.from_buffer(ret))
 
 
 @ffi.def_extern()
 def alphasq2(q2, n):
-    """Returns the alpha strong coupling at specific q2 value."""
+    """Returns the alpha strong coupling at for an array of q2 values."""
     global pdf
     q2_numpy = np.frombuffer(ffi.buffer(q2, n*ffi.sizeof('double')), dtype='double')
     ret = pdf.alphasQ2(q2_numpy).numpy()