update docstring

modopt/opt/proximity.py

@@ -237,6 +237,8 @@ class LowRankMatrix(ProximityParent):
     lowr_type : {'standard', 'ngole'}
         Low-rank implementation (options are 'standard' or 'ngole', default is
         'standard')
+    initial_rank: int, optional
+        Initial guess of the rank of future input_data. If provided this will save computation time.
     operator : class
         Operator class ('ngole' only)
 
@@ -293,7 +295,6 @@ def _op_method(self, input_data, extra_factor=1.0, rank=None):
         extra_factor : float
             Additional multiplication factor (default is ``1.0``)
         rank: int, optional
-            An estimation of the rank to save computation in standard mode.
             An estimation of the rank to save computation time in standard mode, if not set an internal estimation is used.
 
         Returns