From b921279958b591d86fa8950b132fa7f320240723 Mon Sep 17 00:00:00 2001
From: Joshua Shields <54691495+jvshields@users.noreply.github.com>
Date: Mon, 14 Oct 2024 10:46:08 -0400
Subject: [PATCH] use np interpolator instead of scipy (#217)

---
 stardis/plasma/base.py                                |  7 ++++---
 .../opacities/opacities_solvers/util.py               | 11 +++--------
 2 files changed, 7 insertions(+), 11 deletions(-)

diff --git a/stardis/plasma/base.py b/stardis/plasma/base.py
index 017a216e..25bec3e6 100644
--- a/stardis/plasma/base.py
+++ b/stardis/plasma/base.py
@@ -3,7 +3,6 @@
 import logging
 
 from astropy import constants as const, units as u
-from scipy.interpolate import interp1d
 
 from tardis.plasma.base import BasePlasma
 from tardis.plasma.properties.base import (
@@ -118,11 +117,13 @@ class H2PlusDensity(ProcessingPlasmaProperty):
     outputs = ("h2_plus_density",)
 
     def calculate(self, ion_number_density, t_rad):
-        interp_Ks = interp1d(H2_PLUS_K_SAMPLE_TEMPS, H2_PLUS_K_EQUILIBRIUM_CONSTANT)
         h_neutral_density = ion_number_density.loc[1, 0]
         h_plus_density = ion_number_density.loc[1, 1]
+        resampled_Ks = np.interp(
+            t_rad, H2_PLUS_K_SAMPLE_TEMPS, H2_PLUS_K_EQUILIBRIUM_CONSTANT
+        )
         return (
-            h_neutral_density * h_plus_density / interp_Ks(t_rad) * 1e-19
+            h_neutral_density * h_plus_density / resampled_Ks * 1e-19
         )  # scale factor from Stancil 1994 table 1
 
 
diff --git a/stardis/radiation_field/opacities/opacities_solvers/util.py b/stardis/radiation_field/opacities/opacities_solvers/util.py
index 1216ebb6..7e297e80 100644
--- a/stardis/radiation_field/opacities/opacities_solvers/util.py
+++ b/stardis/radiation_field/opacities/opacities_solvers/util.py
@@ -4,7 +4,7 @@
 from astropy import units as u, constants as const
 from tardis.util.base import species_string_to_tuple
 
-from scipy.interpolate import interp1d, LinearNDInterpolator
+from scipy.interpolate import LinearNDInterpolator
 
 
 def sigma_file(tracing_lambdas, temperatures, fpath, opacity_source=None):
@@ -83,16 +83,11 @@ def sigma_file(tracing_lambdas, temperatures, fpath, opacity_source=None):
         h_minus_bf_table = pd.read_csv(
             fpath, header=None, comment="#", names=["wavelength", "cross_section"]
         )
-        linear_interp_1d_from_file = interp1d(
+        sigmas = np.interp(
+            tracing_lambdas,
             h_minus_bf_table.wavelength.values,
             h_minus_bf_table.cross_section.values,
-            bounds_error=False,
-            fill_value=(
-                h_minus_bf_table.cross_section.iloc[0],
-                h_minus_bf_table.cross_section.iloc[-1],
-            ),
         )
-        sigmas = linear_interp_1d_from_file(tracing_lambdas)
 
     else:
         raise ValueError(f"Unknown opacity_source: {opacity_source}")