diff --git a/matlab/@ucf/ucf.m b/matlab/@ucf/ucf.m
index c5dd890..b31c9cf 100644
--- a/matlab/@ucf/ucf.m
+++ b/matlab/@ucf/ucf.m
@@ -86,8 +86,8 @@ classdef ucf < handle
       % ? verbosity         verbose output? (default: false)
       % ? debug             debug output? (default: false)
       par = inputParser;
-      addOptional(par,'verbosity',0,@isnumeric);
-      addOptional(par,'debug',0,@isnumeric);
+      addParameter(par,'verbosity',0,@isnumeric);
+      addParameter(par,'debug',0,@isnumeric);
       parse(par,varargin{:});
       obj.resetPublicProperties();
       obj.resetPrivateProperties();
@@ -212,9 +212,9 @@ classdef ucf < handle
       % ? rank            proc rank (default: [0,0,0,0])
       % ? endian          endianess {'n' (dafault),'a','l','s','b'}
       par = inputParser;
-      addOptional(par,'type','field',@ischar);
-      addOptional(par,'rank',[0,0,0,0],@(x)(isnumeric(x)&&numel(x)==4));
-      addOptional(par,'endian','n',@ischar);
+      addParameter(par,'type','field',@ischar);
+      addParameter(par,'rank',[0,0,0,0],@(x)(isnumeric(x)&&numel(x)==4));
+      addParameter(par,'endian','n',@ischar);
       parse(par,varargin{:});
       %
       obj.File   = file;                            % add filename as object property
@@ -529,7 +529,7 @@ classdef ucf < handle
       % Input
       % ? istep           step index (default: -1, all steps)
       par = inputParser;
-      addOptional(par,'istep',-1,@isnumeric);
+      addParameter(par,'istep',-1,@isnumeric);
       parse(par,varargin{:});
       if par.Results.istep==-1
         stime = obj.timeStep;
diff --git a/matlab/read_field_chunk_ucf.m b/matlab/read_field_chunk_ucf.m
index cbdbdcc..4b70d39 100644
--- a/matlab/read_field_chunk_ucf.m
+++ b/matlab/read_field_chunk_ucf.m
@@ -20,12 +20,12 @@ function [data,ib,jb,kb,nxl,nyl,nzl,ighost] = read_field_chunk_ucf(file,field,va
 
     % Parse optional input arguments
     par = inputParser;
-    addOptional(par,'step',1,@isnumeric);
-    addOptional(par,'ghost',1,@isnumeric);
-    addOptional(par,'verbosity',0,@isnumeric);
-    addOptional(par,'debug',0,@isnumeric);
-    addOptional(par,'tarmode',0,@isnumeric);
-    addOptional(par,'rank',0,@isnumeric);
+    addParameter(par,'step',1,@isnumeric);
+    addParameter(par,'ghost',1,@isnumeric);
+    addParameter(par,'verbosity',0,@isnumeric);
+    addParameter(par,'debug',0,@isnumeric);
+    addParameter(par,'tarmode',0,@isnumeric);
+    addParameter(par,'rank',0,@isnumeric);
     parse(par,varargin{:});
     istep     = par.Results.step;
     keepghost = par.Results.ghost;
diff --git a/matlab/read_field_complete_ucf.m b/matlab/read_field_complete_ucf.m
index 1072cf5..892c571 100644
--- a/matlab/read_field_complete_ucf.m
+++ b/matlab/read_field_complete_ucf.m
@@ -15,10 +15,10 @@ function [q] = read_field_complete_ucf(file,field,varargin)
 
     % Parse optional input arguments
     par = inputParser;
-    addOptional(par,'timestep',1,@isnumeric);
-    addOptional(par,'verbosity',0,@isnumeric);
-    addOptional(par,'debug',0,@isnumeric);
-    addOptional(par,'tarmode',0,@isnumeric);
+    addParameter(par,'timestep',1,@isnumeric);
+    addParameter(par,'verbosity',0,@isnumeric);
+    addParameter(par,'debug',0,@isnumeric);
+    addParameter(par,'tarmode',0,@isnumeric);
     parse(par,varargin{:});
     istep = par.Results.timestep;
 
diff --git a/matlab/read_grid_ucf.m b/matlab/read_grid_ucf.m
index 989032f..3385fcb 100644
--- a/matlab/read_grid_ucf.m
+++ b/matlab/read_grid_ucf.m
@@ -14,9 +14,9 @@ function [xu,yu,zu,xv,yv,zv,xw,yw,zw,xp,yp,zp] = read_grid_ucf(file,varargin)
 
     % Parse optional input arguments
     par = inputParser;
-    addOptional(par,'verbosity',0,@isnumeric);
-    addOptional(par,'debug',0,@isnumeric);
-    addOptional(par,'tarmode',0,@isnumeric);
+    addParameter(par,'verbosity',0,@isnumeric);
+    addParameter(par,'debug',0,@isnumeric);
+    addParameter(par,'tarmode',0,@isnumeric);
     parse(par,varargin{:});
 
     % Define sets to be read
diff --git a/matlab/read_parameters_ucf.m b/matlab/read_parameters_ucf.m
index b985741..93192b7 100644
--- a/matlab/read_parameters_ucf.m
+++ b/matlab/read_parameters_ucf.m
@@ -11,8 +11,8 @@ function [params] = read_parameters_ucf(file,varargin)
   
   % Parse optional input arguments
   par = inputParser;
-  addOptional(par,'verbosity',0,@isnumeric);
-  addOptional(par,'tarmode',0,@isnumeric);
+  addParameter(par,'verbosity',0,@isnumeric);
+  addParameter(par,'tarmode',0,@isnumeric);
   parse(par,varargin{:});
   % Open file
   obj = ini('verbosity',par.Results.verbosity);
diff --git a/matlab/read_particle_balancing_ucf.m b/matlab/read_particle_balancing_ucf.m
index c628be3..bda3f6c 100644
--- a/matlab/read_particle_balancing_ucf.m
+++ b/matlab/read_particle_balancing_ucf.m
@@ -13,9 +13,9 @@ function [iproc,nmaster,nslave,stime] = read_particle_balancing_ucf(file,varargi
     
     % Parse optional input arguments
     par = inputParser;
-    addOptional(par,'timestep',1,@isnumeric);
-    addOptional(par,'verbosity',0,@isnumeric);
-    addOptional(par,'debug',0,@isnumeric);
+    addParameter(par,'timestep',1,@isnumeric);
+    addParameter(par,'verbosity',0,@isnumeric);
+    addParameter(par,'debug',0,@isnumeric);
     parse(par,varargin{:});
     istep = par.Results.timestep;
     
diff --git a/matlab/read_particles_ucf.m b/matlab/read_particles_ucf.m
index 721d6cc..be92a15 100644
--- a/matlab/read_particles_ucf.m
+++ b/matlab/read_particles_ucf.m
@@ -19,11 +19,11 @@ function [pp,col,stime] = read_particles_ucf(file,varargin)
     
     % Parse optional input arguments
     par = inputParser;
-    addOptional(par,'step',0,@isnumeric);
-    addOptional(par,'format','array',@ischar);
-    addOptional(par,'verbosity',0,@isnumeric);
-    addOptional(par,'debug',0,@isnumeric);
-    addOptional(par,'tarmode',0,@isnumeric);
+    addParameter(par,'step',0,@isnumeric);
+    addParameter(par,'format','array',@ischar);
+    addParameter(par,'verbosity',0,@isnumeric);
+    addParameter(par,'debug',0,@isnumeric);
+    addParameter(par,'tarmode',0,@isnumeric);
     parse(par,varargin{:});
     istep     = par.Results.step;
     mlformat  = par.Results.format;
diff --git a/matlab/read_procgrid_ucf.m b/matlab/read_procgrid_ucf.m
index 21aa13c..f1bea70 100644
--- a/matlab/read_procgrid_ucf.m
+++ b/matlab/read_procgrid_ucf.m
@@ -19,9 +19,9 @@ function [ibegu,iendu,jbegu,jendu,kbegu,kendu,...
     
     % Parse optional input arguments
     par = inputParser;
-    addOptional(par,'verbosity',0,@isnumeric);
-    addOptional(par,'debug',0,@isnumeric);
-    addOptional(par,'tarmode',0,@isnumeric);
+    addParameter(par,'verbosity',0,@isnumeric);
+    addParameter(par,'debug',0,@isnumeric);
+    addParameter(par,'tarmode',0,@isnumeric);
     parse(par,varargin{:});
     
     % Define sets to be read
diff --git a/matlab/read_scal_chunk_ucf.m b/matlab/read_scal_chunk_ucf.m
index 3af187d..03d5fb4 100644
--- a/matlab/read_scal_chunk_ucf.m
+++ b/matlab/read_scal_chunk_ucf.m
@@ -17,12 +17,12 @@ function [s,ib,jb,kb,nxl,nyl,nzl,ighost] = read_scal_chunk_ucf(file,varargin)
 
     % Parse optional input arguments
     par = inputParser;
-    addOptional(par,'step',1,@isnumeric);
-    addOptional(par,'ghost',1,@isnumeric);
-    addOptional(par,'verbosity',0,@isnumeric);
-    addOptional(par,'debug',0,@isnumeric);
-    addOptional(par,'tarmode',0,@isnumeric);
-    addOptional(par,'rank',0,@isnumeric);
+    addParameter(par,'step',1,@isnumeric);
+    addParameter(par,'ghost',1,@isnumeric);
+    addParameter(par,'verbosity',0,@isnumeric);
+    addParameter(par,'debug',0,@isnumeric);
+    addParameter(par,'tarmode',0,@isnumeric);
+    addParameter(par,'rank',0,@isnumeric);
     parse(par,varargin{:});
     istep     = par.Results.step;
     keepghost = par.Results.ghost;
diff --git a/matlab/read_scal_complete_ucf.m b/matlab/read_scal_complete_ucf.m
index e747976..0021635 100644
--- a/matlab/read_scal_complete_ucf.m
+++ b/matlab/read_scal_complete_ucf.m
@@ -12,10 +12,10 @@ function [s] = read_scal_complete_ucf(file,varargin)
 
     % Parse optional input arguments
     par = inputParser;
-    addOptional(par,'step',1,@isnumeric);
-    addOptional(par,'verbosity',0,@isnumeric);
-    addOptional(par,'debug',0,@isnumeric);
-    addOptional(par,'tarmode',0,@isnumeric);
+    addParameter(par,'step',1,@isnumeric);
+    addParameter(par,'verbosity',0,@isnumeric);
+    addParameter(par,'debug',0,@isnumeric);
+    addParameter(par,'tarmode',0,@isnumeric);
     parse(par,varargin{:});
     istep = par.Results.step;
 
diff --git a/matlab/read_statistics_channel_scal_ucf.m b/matlab/read_statistics_channel_scal_ucf.m
index 10140ec..acef424 100644
--- a/matlab/read_statistics_channel_scal_ucf.m
+++ b/matlab/read_statistics_channel_scal_ucf.m
@@ -2,8 +2,8 @@ function [tbeg,tend,nstat,sm,ss,su,sv] = read_statistics_channel_scal_ucf(file,v
 
     % Parse optional input arguments
     par = inputParser;
-    addOptional(par,'verbosity',0,@isnumeric);
-    addOptional(par,'debug',0,@isnumeric);
+    addParameter(par,'verbosity',0,@isnumeric);
+    addParameter(par,'debug',0,@isnumeric);
     parse(par,varargin{:});
 
     % Define sets to be read
diff --git a/matlab/read_statistics_channel_ucf.m b/matlab/read_statistics_channel_ucf.m
index b0b97a3..68f9a75 100644
--- a/matlab/read_statistics_channel_ucf.m
+++ b/matlab/read_statistics_channel_ucf.m
@@ -2,8 +2,8 @@ function [tbeg,tend,nstat,um,uu,vv,ww,uv,uub,uvb,varargout] = read_statistics_ch
 
     % Parse optional input arguments
     par = inputParser;
-    addOptional(par,'verbosity',0,@isnumeric);
-    addOptional(par,'debug',0,@isnumeric);
+    addParameter(par,'verbosity',0,@isnumeric);
+    addParameter(par,'debug',0,@isnumeric);
     parse(par,varargin{:});
 
     % Define sets to be read
diff --git a/matlab/read_uvwp_chunk_ucf.m b/matlab/read_uvwp_chunk_ucf.m
index 49b7b2a..b4be245 100644
--- a/matlab/read_uvwp_chunk_ucf.m
+++ b/matlab/read_uvwp_chunk_ucf.m
@@ -23,12 +23,12 @@ function [u,ibu,jbu,kbu,nxul,nyul,nzul,...
 
     % Parse optional input arguments
     par = inputParser;
-    addOptional(par,'step',1,@isnumeric);
-    addOptional(par,'ghost',1,@isnumeric);
-    addOptional(par,'verbosity',0,@isnumeric);
-    addOptional(par,'debug',0,@isnumeric);
-    addOptional(par,'tarmode',0,@isnumeric);
-    addOptional(par,'rank',0,@isnumeric);
+    addParameter(par,'step',1,@isnumeric);
+    addParameter(par,'ghost',1,@isnumeric);
+    addParameter(par,'verbosity',0,@isnumeric);
+    addParameter(par,'debug',0,@isnumeric);
+    addParameter(par,'tarmode',0,@isnumeric);
+    addParameter(par,'rank',0,@isnumeric);
     parse(par,varargin{:});
     istep     = par.Results.step;
     keepghost = par.Results.ghost;
diff --git a/matlab/read_uvwp_complete_ucf.m b/matlab/read_uvwp_complete_ucf.m
index e126a37..6faa95c 100644
--- a/matlab/read_uvwp_complete_ucf.m
+++ b/matlab/read_uvwp_complete_ucf.m
@@ -12,10 +12,10 @@ function [u,v,w,p] = read_uvwp_complete_ucf(file,varargin)
 
     % Parse optional input arguments
     par = inputParser;
-    addOptional(par,'step',1,@isnumeric);
-    addOptional(par,'verbosity',0,@isnumeric);
-    addOptional(par,'debug',0,@isnumeric);
-    addOptional(par,'tarmode',0,@isnumeric);
+    addParameter(par,'step',1,@isnumeric);
+    addParameter(par,'verbosity',0,@isnumeric);
+    addParameter(par,'debug',0,@isnumeric);
+    addParameter(par,'tarmode',0,@isnumeric);
     parse(par,varargin{:});
     istep = par.Results.timestep;
 
diff --git a/matlab/write_particles_ucf.m b/matlab/write_particles_ucf.m
index 61240cc..758ce01 100644
--- a/matlab/write_particles_ucf.m
+++ b/matlab/write_particles_ucf.m
@@ -12,9 +12,9 @@ function [] = write_particles_ucf(file,pp,col,time,varargin)
 
     % Parse variable input
     par = inputParser;
-    addOptional(par,'endian','n',@ischar);
-    addOptional(par,'verbosity',0,@isnumeric);
-    addOptional(par,'debug',0,@isnumeric);
+    addParameter(par,'endian','n',@ischar);
+    addParameter(par,'verbosity',0,@isnumeric);
+    addParameter(par,'debug',0,@isnumeric);
     parse(par,varargin{:});
 
     ncol = size(pp,1);
diff --git a/matlab/write_scal_chunk_ucf.m b/matlab/write_scal_chunk_ucf.m
index 3b60df6..b1fcf65 100644
--- a/matlab/write_scal_chunk_ucf.m
+++ b/matlab/write_scal_chunk_ucf.m
@@ -16,10 +16,10 @@ function [] = write_scal_chunk_ucf(file,s,ib,jb,kb,nx,ny,nz,time,ighost,varargin
 
     % Parse variable input
     par = inputParser;
-    addOptional(par,'rank',[0,0,0,0],@(x)isnumeric(x)&&numel(x)==4);
-    addOptional(par,'endian','n',@ischar);
-    addOptional(par,'verbosity',0,@isnumeric);
-    addOptional(par,'debug',0,@isnumeric);
+    addParameter(par,'rank',[0,0,0,0],@(x)isnumeric(x)&&numel(x)==4);
+    addParameter(par,'endian','n',@ischar);
+    addParameter(par,'verbosity',0,@isnumeric);
+    addParameter(par,'debug',0,@isnumeric);
     parse(par,varargin{:});
 
     % Determine number of scalar fields
diff --git a/matlab/write_scal_complete_ucf.m b/matlab/write_scal_complete_ucf.m
index 0196e57..b98d18d 100644
--- a/matlab/write_scal_complete_ucf.m
+++ b/matlab/write_scal_complete_ucf.m
@@ -14,9 +14,9 @@ function [] = write_scal_complete_ucf(file,s,ibegp,iendp,jbegp,jendp,kbegp,kendp
 
     % Parse variable input
     par = inputParser;
-    addOptional(par,'endian','n',@ischar);
-    addOptional(par,'verbosity',0,@isnumeric);
-    addOptional(par,'debug',0,@isnumeric);
+    addParameter(par,'endian','n',@ischar);
+    addParameter(par,'verbosity',0,@isnumeric);
+    addParameter(par,'debug',0,@isnumeric);
     parse(par,varargin{:});
 
     % Parse filename
diff --git a/matlab/write_uvwp_chunk_ucf.m b/matlab/write_uvwp_chunk_ucf.m
index 220c71f..89bfec9 100644
--- a/matlab/write_uvwp_chunk_ucf.m
+++ b/matlab/write_uvwp_chunk_ucf.m
@@ -26,10 +26,10 @@ function [] = write_uvwp_chunk_ucf(file,...
 
     % Parse variable input
     par = inputParser;
-    addOptional(par,'rank',[0,0,0,0],@(x)isnumeric(x)&&numel(x)==4);
-    addOptional(par,'endian','n',@ischar);
-    addOptional(par,'verbosity',0,@isnumeric);
-    addOptional(par,'debug',0,@isnumeric);
+    addParameter(par,'rank',[0,0,0,0],@(x)isnumeric(x)&&numel(x)==4);
+    addParameter(par,'endian','n',@ischar);
+    addParameter(par,'verbosity',0,@isnumeric);
+    addParameter(par,'debug',0,@isnumeric);
     parse(par,varargin{:});
 
     % Create file and write to it
diff --git a/matlab/write_uvwp_complete_ucf.m b/matlab/write_uvwp_complete_ucf.m
index 8b017e1..3e13967 100644
--- a/matlab/write_uvwp_complete_ucf.m
+++ b/matlab/write_uvwp_complete_ucf.m
@@ -24,9 +24,9 @@ function [] = write_uvwp_complete_ucf(file,...
 
     % Parse variable input
     par = inputParser;
-    addOptional(par,'endian','n',@ischar);
-    addOptional(par,'verbosity',0,@isnumeric);
-    addOptional(par,'debug',0,@isnumeric);
+    addParameter(par,'endian','n',@ischar);
+    addParameter(par,'verbosity',0,@isnumeric);
+    addParameter(par,'debug',0,@isnumeric);
     parse(par,varargin{:});
 
     % Parse filename
diff --git a/matlab/write_uvwp_newmesh_ucf.m b/matlab/write_uvwp_newmesh_ucf.m
index 3176412..9fbb634 100644
--- a/matlab/write_uvwp_newmesh_ucf.m
+++ b/matlab/write_uvwp_newmesh_ucf.m
@@ -33,10 +33,10 @@ function [] = write_uvwp_newmesh_ucf(file,...
 
     % Parse variable input
     par = inputParser;
-    addOptional(par,'method','cubic',@ischar);
-    addOptional(par,'endian','n',@ischar);
-    addOptional(par,'verbosity',0,@isnumeric);
-    addOptional(par,'debug',0,@isnumeric);
+    addParameter(par,'method','cubic',@ischar);
+    addParameter(par,'endian','n',@ischar);
+    addParameter(par,'verbosity',0,@isnumeric);
+    addParameter(par,'debug',0,@isnumeric);
     parse(par,varargin{:});
 
     % Parse filename