bug: protect use of jnp if jax is not installed

Author: mrava87

pylops/utils/backend.py

@@ -128,7 +128,7 @@ def get_array_module(x: npt.ArrayLike) -> ModuleType:
 
     """
     if deps.cupy_enabled or deps.jax_enabled:
-        if isinstance(x, jnp.ndarray):
+        if deps.jax_enabled and isinstance(x, jnp.ndarray):
             return jnp
         elif deps.cupy_enabled:
             return cp.get_array_module(x)
@@ -153,7 +153,7 @@ def get_convolve(x: npt.ArrayLike) -> Callable:
 
     """
     if deps.cupy_enabled or deps.jax_enabled:
-        if isinstance(x, jnp.ndarray):
+        if deps.jax_enabled and isinstance(x, jnp.ndarray):
             return j_convolve
         elif deps.cupy_enabled and cp.get_array_module(x) == cp:
             return cp_convolve
@@ -178,7 +178,7 @@ def get_fftconvolve(x: npt.ArrayLike) -> Callable:
 
     """
     if deps.cupy_enabled or deps.jax_enabled:
-        if isinstance(x, jnp.ndarray):
+        if deps.jax_enabled and isinstance(x, jnp.ndarray):
             return j_fftconvolve
         elif deps.cupy_enabled and cp.get_array_module(x) == cp:
             return cp_fftconvolve
@@ -203,7 +203,7 @@ def get_oaconvolve(x: npt.ArrayLike) -> Callable:
 
     """
     if deps.cupy_enabled or deps.jax_enabled:
-        if isinstance(x, jnp.ndarray):
+        if deps.jax_enabled and isinstance(x, jnp.ndarray):
             raise NotImplementedError(
                 "oaconvolve not implemented in "
                 "jax. Consider using a different"
@@ -232,7 +232,7 @@ def get_correlate(x: npt.ArrayLike) -> Callable:
 
     """
     if deps.cupy_enabled or deps.jax_enabled:
-        if isinstance(x, jnp.ndarray):
+        if deps.jax_enabled and isinstance(x, jnp.ndarray):
             return jax.scipy.signal.correlate
         elif deps.cupy_enabled and cp.get_array_module(x) == cp:
             return cp_correlate
@@ -303,7 +303,7 @@ def get_block_diag(x: npt.ArrayLike) -> Callable:
 
     """
     if deps.cupy_enabled or deps.jax_enabled:
-        if isinstance(x, jnp.ndarray):
+        if deps.jax_enabled and isinstance(x, jnp.ndarray):
             return jnp_block_diag
         elif deps.cupy_enabled and cp.get_array_module(x) == cp:
             return cp_block_diag
@@ -328,7 +328,7 @@ def get_toeplitz(x: npt.ArrayLike) -> Callable:
 
     """
     if deps.cupy_enabled or deps.jax_enabled:
-        if isinstance(x, jnp.ndarray):
+        if deps.jax_enabled and isinstance(x, jnp.ndarray):
             return jnp_toeplitz
         elif deps.cupy_enabled and cp.get_array_module(x) == cp:
             return cp_toeplitz