Merge pull request #1775 from qiboteam/abstract

Add `max`, `min`, and `var` methods to abstract `Backend`

Author: renatomello

src/qibo/backends/abstract.py

@@ -280,6 +280,9 @@ def concatenate(self, tup: Tuple[ArrayLike, ...], **kwargs) -> ArrayLike:
     def conj(self, array: ArrayLike) -> ArrayLike:
         return self.engine.conj(array)
 
+    def coo_matrix(self, array: ArrayLike, **kwargs) -> ArrayLike:  # pragma: no cover
+        raise_error(NotImplementedError)
+
     def copy(self, array: ArrayLike, **kwargs) -> ArrayLike:
         return self.engine.copy(array, **kwargs)
 
@@ -419,9 +422,19 @@ def matrix_norm(
 
         return self.engine.linalg.norm(state, order, **kwargs)
 
+    def max(
+        self, array: ArrayLike, **kwargs
+    ) -> Union[float, int, complex, ArrayLike]:  # pragma: no cover
+        return self.engine.max(array, **kwargs)
+
     def mean(self, array: ArrayLike, **kwargs) -> Union[float, complex, ArrayLike]:
         return self.engine.mean(array, **kwargs)
 
+    def min(
+        self, array: ArrayLike, **kwargs
+    ) -> Union[float, int, complex, ArrayLike]:  # pragma: no cover
+        return self.engine.min(array, **kwargs)
+
     def nonzero(self, array: ArrayLike) -> ArrayLike:
         return self.engine.nonzero(array)
 
@@ -635,6 +648,11 @@ def unique(
     ) -> Union[ArrayLike, Tuple[ArrayLike, ArrayLike]]:
         return self.engine.unique(array, **kwargs)
 
+    def var(
+        self, array: ArrayLike, **kwargs
+    ) -> Union[float, ArrayLike]:  # pragma: no cover
+        return self.engine.var(array, **kwargs)
+
     def vector_norm(
         self,
         state: ArrayLike,