diff --git a/matlab/catalog/eliminateEmptyValues.m b/matlab/catalog/eliminateEmptyValues.m
index 1bc2a6c..fe24199 100644
--- a/matlab/catalog/eliminateEmptyValues.m
+++ b/matlab/catalog/eliminateEmptyValues.m
@@ -6,6 +6,20 @@
 % --------------
 %
 function varargout = eliminateEmptyValues(varargin)
+% ELIMINATEEMPTYVALUES Removes empty values from input columns
+%
+%   [out1, out2, ...] = ELIMINATEEMPTYVALUES(in1, in2, ...) removes empty
+%   or NaN values from the input columns. The function takes a variable
+%   number of input arguments and returns the corresponding output columns
+%   without empty or NaN values. The inputs can be numeric arrays or cell
+%   arrays, and the function will remove entries that are empty in any of
+%   the input columns.
+%
+%   Example:
+%       [a, b] = eliminateEmptyValues([1, NaN, 3], {'A', '', 'C'});
+%       % Result: a = [1, 3], b = {'A', 'C'}
+%
+
     if isempty(varargin)
         return;
     end
@@ -21,4 +35,4 @@ function varargout = eliminateEmptyValues(varargin)
     for i = 1:length(varargin)
         varargout{i} = varargin{i}(indexes);
     end
-end
\ No newline at end of file
+end
diff --git a/matlab/catalog/extractColumns.m b/matlab/catalog/extractColumns.m
index c3149a7..8bc90ec 100644
--- a/matlab/catalog/extractColumns.m
+++ b/matlab/catalog/extractColumns.m
@@ -6,14 +6,36 @@
 % --------------
 %
 function [varargout] = extractColumns(catalog, varargin)
-    for i=1:length(varargin)
+% EXTRACTCOLUMNS Extracts specified columns from a catalog structure
+%
+%   [col1, col2, ...] = EXTRACTCOLUMNS(catalog, 'colName1', 'colName2', ...)
+%   extracts the columns with the specified names from the catalog
+%   structure. The catalog is expected to be an array of structures where
+%   each structure has fields 'field' and 'val'. The function returns the
+%   values of the requested columns.
+%
+%   Example:
+%       catalog(1).field = 'ID'; catalog(1).val = [1, 2, 3];
+%       catalog(2).field = 'Time'; catalog(2).val = [100, 200, 300];
+%       [id, time] = extractColumns(catalog, 'ID', 'Time');
+%       % Result: id = [1, 2, 3], time = [100, 200, 300]
+%
+%   See also: FINDCATALOGCOLUMN.
+
+    for i = 1:length(varargin)
         colName = varargin{i};
         varargout{i} = findColumn(catalog, colName);
     end
 end
 
 function column = findColumn(catalog, colName)
-    for c=1:length(catalog)
+% FINDCOLUMN Helper function to find the values of a column in a catalog
+%
+%   column = FINDCOLUMN(catalog, colName) searches the catalog structure
+%   for the specified column name and returns its values. If the column
+%   does not exist, an error is thrown.
+
+    for c = 1:length(catalog)
         if strcmp(catalog(c).field, colName)
             column = catalog(c).val;
             break;
@@ -22,4 +44,4 @@ function column = findColumn(catalog, colName)
     if exist('column') ~= 1
         error('no column named %s', colName);
     end
-end
\ No newline at end of file
+end
diff --git a/matlab/catalog/findCatalogColumn.m b/matlab/catalog/findCatalogColumn.m
index 0b9c974..00926d3 100644
--- a/matlab/catalog/findCatalogColumn.m
+++ b/matlab/catalog/findCatalogColumn.m
@@ -3,11 +3,25 @@
 % Copyright © 2022 ACK Cyfronet AGH, Poland.
 % --------------
 %
-% Returns index of the column with the specified colName within the given catalog
-%
-% TODO use this function in extractColumns.m
 function columnIdx = findCatalogColumn(catalog, colName)
-    for c=1:length(catalog)
+% FINDCATALOGCOLUMN Find the index of a column in a catalog
+%
+%   columnIdx = FINDCATALOGCOLUMN(catalog, colName) returns the index of
+%   the column with the specified name within the given catalog structure.
+%   The catalog is expected to be an array of structures where each
+%   structure has a 'field' representing the column name.
+%
+%   Example:
+%       catalog(1).field = 'ID'; catalog(2).field = 'Time';
+%       idx = findCatalogColumn(catalog, 'Time');
+%       % Result: idx = 2
+%
+%   Note: This function is intended to be used in conjunction with other
+%   catalog processing functions.
+%
+%   See also: EXTRACTCOLUMNS.
+
+    for c = 1:length(catalog)
         if strcmp(catalog(c).field, colName)
             columnIdx = c;
             break;
@@ -16,4 +30,4 @@ function columnIdx = findCatalogColumn(catalog, colName)
     if exist('columnIdx') ~= 1
         error('no column named %s', colName);
     end
-end
\ No newline at end of file
+end
diff --git a/matlab/catalog/sortByTime.m b/matlab/catalog/sortByTime.m
index 47954e4..c077538 100644
--- a/matlab/catalog/sortByTime.m
+++ b/matlab/catalog/sortByTime.m
@@ -4,12 +4,28 @@
 % -----------------
 %
 function [sortedCatalog] = sortByTime(catalog)
+% SORTBYTIME Sorts a catalog structure by the 'Time' column
+%
+%   sortedCatalog = SORTBYTIME(catalog) sorts the given catalog structure
+%   based on the values in the 'Time' column. The catalog is expected to be
+%   an array of structures where each structure has fields 'field' and
+%   'val'. The function rearranges the catalog entries in ascending order
+%   of time.
+%
+%   Example:
+%       catalog(1).field = 'ID'; catalog(1).val = [3, 2, 1];
+%       catalog(2).field = 'Time'; catalog(2).val = [300, 200, 100];
+%       sortedCatalog = sortByTime(catalog);
+%       % Result: sortedCatalog(2).val = [100, 200, 300]
+%
+%   See also: FINDCATALOGCOLUMN, SORTROWS.
+
   timeColIndex = find(strcmp('Time', {catalog.field}));
   if ~isempty(timeColIndex)
       [~, sortedIndexes] = sortrows(catalog(timeColIndex).val);
-      for i=1:length(catalog)
+      for i = 1:length(catalog)
           catalog(i).val = catalog(i).val(sortedIndexes);
       end
   end
   sortedCatalog = catalog;
-end
\ No newline at end of file
+end
diff --git a/matlab/unitutils/wavecut.m b/matlab/unitutils/wavecut.m
index 33e7274..1491783 100644
--- a/matlab/unitutils/wavecut.m
+++ b/matlab/unitutils/wavecut.m
@@ -4,7 +4,20 @@
 % -----------------
 %
 function [wc]=wavecut(wf,startp,endp)
-
+% WAVECUT Extracts a segment of a waveform
+%
+%   [WC] = WAVECUT(WF, STARTP, ENDP) extracts a segment of the waveform WF
+%   starting at position STARTP and ending at position ENDP. The input
+%   waveform WF is assumed to be a vector. STARTP and ENDP should be
+%   numeric values indicating the start and end positions of the desired
+%   segment.
+%
+%   Example:
+%       wf = sin(0:0.01:2*pi);
+%       segment = wavecut(wf, 50, 150);
+%       plot(segment);
+%
+%   See also: other functions that process waveforms.
 wc=wf(round(startp):round(endp));
 
 end
\ No newline at end of file