Replace interpolation package

astromodels/functions/functions_1D/absorption.py

@@ -7,7 +7,6 @@
 import numba as nb
 import numpy as np
 from astropy.io import fits
-from interpolation import interp
 
 from astromodels.functions.function import Function1D, FunctionMeta
 from astromodels.utils import _get_data_file_path
@@ -190,6 +189,10 @@ def _init_xsect(self):
 
         self.xsect_ene, self.xsect_val = phabs.xsect_table
 
+        assert np.all(
+            np.diff(self.xsect_ene) > 0
+        ), "xsec_ene must be strictly increasing otherwise interpolation fails"
+
     @property
     def abundance_table_info(self):
         print(phabs.info)
@@ -207,7 +210,7 @@ def evaluate(self, x, NH, redshift):
             _redshift = redshift
             _x = x
 
-        xsect_interp = interp(self.xsect_ene, self.xsect_val, _x * (1 + _redshift))
+        xsect_interp = np.interp(_x * (1 + _redshift), self.xsect_ene, self.xsect_val)
 
         # evaluate the exponential with numba
 
@@ -280,6 +283,9 @@ def _init_xsect(self):
         tbabs.set_table(self.abundance_table.value)
 
         self.xsect_ene, self.xsect_val = tbabs.xsect_table
+        assert np.all(
+            np.diff(self.xsect_ene) > 0
+        ), "xsec_ene must be strictly increasing otherwise interpolation fails"
 
         log.debug(f"updated the TbAbs table to {self.abundance_table.value}")
 
@@ -300,7 +306,7 @@ def evaluate(self, x, NH, redshift):
             _redshift = redshift
             _x = x
 
-        xsect_interp = interp(self.xsect_ene, self.xsect_val, _x * (1 + _redshift))
+        xsect_interp = np.interp(_x * (1 + _redshift), self.xsect_ene, self.xsect_val)
 
         spec = _numba_eval(NH, xsect_interp) * _y_unit
 
@@ -355,6 +361,10 @@ def _init_xsect(self):
 
         self.xsect_ene, self.xsect_val = wabs.xsect_table
 
+        assert np.all(
+            np.diff(self.xsect_ene) > 0
+        ), "xsec_ene must be strictly increasing otherwise interpolation fails"
+
     @property
     def abundance_table_info(self):
         print(wabs.info)
@@ -372,7 +382,7 @@ def evaluate(self, x, NH, redshift):
             _redshift = redshift
             _x = x
 
-        xsect_interp = interp(self.xsect_ene, self.xsect_val, _x * (1 + _redshift))
+        xsect_interp = np.interp(_x * (1 + _redshift), self.xsect_ene, self.xsect_val)
 
         spec = _numba_eval(NH, xsect_interp) * _y_unit
 

astromodels/functions/template_model.py

@@ -12,8 +12,6 @@
 import h5py
 import numpy as np
 import scipy.interpolate
-from interpolation import interp
-from interpolation.splines import eval_linear
 
 from astromodels.core.parameter import Parameter
 from astromodels.functions.function import Function1D, FunctionMeta
@@ -63,7 +61,7 @@ def __init__(self, grid, values):
         self._values = np.ascontiguousarray(values)
 
     def __call__(self, v):
-        return eval_linear(self._grid, self._values, v)
+        return scipy.interpolate.interpn(self._grid, self._values, v)
 
 
 class UnivariateSpline(object):
@@ -72,7 +70,10 @@ def __init__(self, x, y):
         self._y = y
 
     def __call__(self, v):
-        return interp(self._x, self._y, v)
+        if isinstance(self._x, np.ndarray) and isinstance(self._y, np.ndarray):
+            return np.interp(v, self._x, self._y.reshape(self._x.shape))
+        else:
+            return np.interp(v, self._x, self._y)
 
 
 class TemplateModelFactory(object):

astromodels/tests/test_template_model.py

@@ -15,7 +15,10 @@
     TemplateModelFactory,
     XSPECTableModel,
 )
-from astromodels.functions.template_model import convert_old_table_model
+from astromodels.functions.template_model import (
+    convert_old_table_model,
+    UnivariateSpline,
+)
 from astromodels.utils import _get_data_file_path
 from astromodels.utils.logging import update_logging_level
 
@@ -291,3 +294,13 @@ def test_table_conversion():
     npt.assert_almost_equal(test(xx), old_table(xx))
 
     p.unlink()
+
+
+def test_univariate_spline():
+    univ = UnivariateSpline([0, 1, 2], [3, 4, 5])
+    res = univ(1.5)
+    assert np.isclose(res, 4.5)
+
+    univ_np = UnivariateSpline(np.array([0, 1, 2]), np.array([3, 4, 5]))
+    res_np = univ_np(1.5)
+    assert np.isclose(res_np, 4.5)

pyproject.toml

@@ -27,8 +27,6 @@
 	"astropy>=1.2",
 	"dill",
 	"future",
-	"legacy-cgi; python_version >= '3.13'",
-	"interpolation>=2.2.3",
 	"numba",
 	"h5py",
 	"pandas",