Fix incorrect array dimensions in docstrings

Author: pulkkins

pysteps/cascade/bandpass_filters.py

@@ -3,21 +3,23 @@
 
 The methods in this module implement the following interface:
 
-    filter_xxx(L, n, optional arguments)
+    filter_xxx(shape, n, optional arguments)
 
-where L is size of the input field, respectively, and n is the number of 
-frequency bands to use.
+where shape is the shape of the input field, respectively, and n is the number 
+of frequency bands to use.
 
 The output of each filter function is a dictionary containing the following 
 key-value pairs:
 
-    weights_1d       2d array of shape (n, L/2) containing 1d filter weights 
+    weights_1d       2d array of shape (n, r) containing 1d filter weights 
                      for each frequency band k=1,2,...,n
-    weights_2d       3d array of shape (n, L, L) containing the 2d filter 
+    weights_2d       3d array of shape (n, M, N) containing the 2d filter 
                      weights for each frequency band k=1,2,...,n
     central_freqs    1d array of shape n containing the central frequencies of 
                      the filters
 
+where r = int(max(N, M)/2)+1
+
 The filter weights are assumed to be normalized so that for any Fourier 
 wavenumber they sum to one.
 """

pysteps/cascade/decomposition.py

@@ -12,9 +12,9 @@
 +-------------------+----------------------------------------------------------+
 |        Key        |                      Value                               |
 +===================+==========================================================+
-|  cascade_levels   | three-dimensional array of shape (n,L,L), where n is the |
-|                   | number of cascade levels and L is the size of the input  |
-|                   | field                                                    |
+|  cascade_levels   | three-dimensional array of shape (k,m,n), where k is the |
+|                   | number of cascade levels and the input fields have shape |
+|                   | (m,n)                                                    |
 +-------------------+----------------------------------------------------------+
 |  means            | list of mean values for each cascade level               |
 +-------------------+----------------------------------------------------------+

pysteps/nowcasts/steps.py

@@ -225,7 +225,7 @@ def forecast(R, V, n_timesteps, n_ens_members, n_cascade_levels,
         R_d.append(R_)
 
     # normalize the cascades and rearrange them into a four-dimensional array 
-    # of shape (n_cascade_levels,ar_order+1,L,L) for the autoregressive model
+    # of shape (n_cascade_levels,ar_order+1,m,n) for the autoregressive model
     R_c,mu,sigma = _stack_cascades(R_d, n_cascade_levels)
     R_d = None
 

pysteps/optflow/darts.py

@@ -28,8 +28,8 @@ def DARTS(Z, **kwargs):
     Parameters
     ----------
     Z : array-like
-      Array of shape (T,L,L) containing a sequence of T two-dimensional input 
-      images of shape (L,L).
+      Array of shape (T,m,n) containing a sequence of T two-dimensional input 
+      images of shape (m,n).
     
     Other Parameters
     ----------------
@@ -57,7 +57,7 @@ def DARTS(Z, **kwargs):
     Returns
     -------
     out : ndarray
-      Three-dimensional array (2,L,L) containing the dense x- and y-components 
+      Three-dimensional array (2,H,W) containing the dense x- and y-components 
       of the motion field.
     
     References