Add new methods ScaleFuncForm::calc and Scales::compatible_with

pineappl/src/boc.rs

@@ -3,6 +3,7 @@
 //!
 //! [`Grid`]: super::grid::Grid
 
+use super::subgrid::NodeValues;
 use float_cmp::approx_eq;
 use itertools::Itertools;
 use serde::{Deserialize, Serialize};
@@ -38,6 +39,24 @@ pub enum ScaleFuncForm {
     QuadraticSum(usize, usize),
 }
 
+impl ScaleFuncForm {
+    /// TODO
+    pub fn calc(&self, node_values: &[NodeValues], kinematics: &[Kinematics]) -> Option<Vec<f64>> {
+        match self {
+            ScaleFuncForm::NoScale => None,
+            &ScaleFuncForm::Scale(index) => Some(
+                node_values[kinematics
+                    .iter()
+                    .position(|&kin| kin == Kinematics::Scale(index))
+                    // UNWRAP: this should be guaranteed by `Grid::new`
+                    .unwrap()]
+                .values(),
+            ),
+            ScaleFuncForm::QuadraticSum(_, _) => todo!(),
+        }
+    }
+}
+
 /// TODO
 #[derive(Clone, Deserialize, Serialize)]
 pub struct Scales {
@@ -49,6 +68,27 @@ pub struct Scales {
     pub frg: ScaleFuncForm,
 }
 
+impl Scales {
+    /// TODO
+    pub fn compatible_with(&self, kinematics: &[Kinematics]) -> bool {
+        for scale in [&self.ren, &self.fac, &self.frg].map(Clone::clone) {
+            match scale {
+                ScaleFuncForm::NoScale => {}
+                ScaleFuncForm::Scale(index)
+                    if kinematics
+                        .iter()
+                        .any(|&kin| kin == Kinematics::Scale(index)) => {}
+                ScaleFuncForm::QuadraticSum(idx1, idx2)
+                    if kinematics.iter().any(|&kin| kin == Kinematics::Scale(idx1))
+                        && kinematics.iter().any(|&kin| kin == Kinematics::Scale(idx2)) => {}
+                _ => return false,
+            }
+        }
+
+        true
+    }
+}
+
 /// Error type keeping information if [`Order::from_str`] went wrong.
 #[derive(Debug, Error, Eq, PartialEq)]
 #[error("{0}")]

pineappl/src/grid.rs

@@ -138,8 +138,9 @@ impl Grid {
     ///
     /// # Panics
     ///
-    /// Panics when the number of PIDs in `channels` is not equal to `convolutions.len()`, or if
-    /// `interps` and `kinematics` have different lengths.
+    /// Panics when the number of PIDs in `channels` is not equal to `convolutions.len()`, or
+    /// `interps` and `kinematics` have different lengths or if `kinematics` are not compatible
+    /// with `scales`.
     #[must_use]
     pub fn new(
         pid_basis: PidBasis,
@@ -168,6 +169,11 @@ impl Grid {
             "interps and kinematics have different lengths"
         );
 
+        assert!(
+            scales.compatible_with(&kinematics),
+            "scales and kinematics are not compatible"
+        );
+
         Self {
             subgrids: Array3::from_shape_simple_fn(
                 (orders.len(), bin_limits.len() - 1, channels.len()),

pineappl/tests/drell_yan_lo.rs

@@ -217,7 +217,7 @@ fn fill_drell_yan_lo_grid(
 
     let scales = Scales {
         ren: ScaleFuncForm::Scale(0),
-        fac: ScaleFuncForm::Scale(1),
+        fac: ScaleFuncForm::Scale(0),
         frg: ScaleFuncForm::NoScale,
     };