[MRG] Remove redundant abs() (#448)

* Remove redundant abs()

* Update RELEASES.md

Author: chaosink

RELEASES.md

@@ -17,8 +17,8 @@
 - Backend version of `ot.partial` and `ot.smooth` (PR #388)
 - Added argument for warmstart of dual potentials in Sinkhorn-based methods in `ot.bregman` (PR #437)
 - Add parameters method in `ot.da.SinkhornTransport` (PR #440)
-- `ot.dr` now uses the new Pymanopt API and POT is compatible with current
-  Pymanopt (PR #443)
+- `ot.dr` now uses the new Pymanopt API and POT is compatible with current Pymanopt (PR #443)
+- Remove the redundant `nx.abs()` at the end of `wasserstein_1d()` (PR #448)
 
 #### Closed issues
 

ot/lp/solver_1d.py

@@ -129,7 +129,7 @@ def wasserstein_1d(u_values, v_values, u_weights=None, v_weights=None, p=1, requ
     diff_quantiles = nx.abs(u_quantiles - v_quantiles)
 
     if p == 1:
-        return nx.sum(delta * nx.abs(diff_quantiles), axis=0)
+        return nx.sum(delta * diff_quantiles, axis=0)
     return nx.sum(delta * nx.power(diff_quantiles, p), axis=0)