function h=subaxis(varargin)
%SUBAXIS Create axes in tiled positions. (just like subplot)
%   Usage:
%      h=subaxis(rows,cols,cellno[,settings])
%      h=subaxis(rows,cols,cellx,celly[,settings])
%      h=subaxis(rows,cols,cellx,celly,spanx,spany[,settings])
%      h=subaxis(hP,rows,cols,cellx,celly,spanx,spany[,settings])
%
% SETTINGS: Spacing,SpacingHoriz,SpacingVert
%           Padding,PaddingRight,PaddingLeft,PaddingTop,PaddingBottom
%           Margin,MarginRight,MarginLeft,MarginTop,MarginBottom
%           Holdaxis
%
%           hP - if entered this is the parent handle for plotting the axes
%
%           all units are relative (e.g from 0 to 1)
%
%           Abbreviations of parameters can be used.. (Eg MR instead of MarginRight)
%           (holdaxis means that it wont delete any axes below.)
%
%
% Example:
%
%   >> subaxis(2,1,1,'SpacingVert',0,'MR',0); 
%   >> imagesc(magic(3))
%   >> subaxis(2,'p',.02);
%   >> imagesc(magic(4))
%
% 2001 / Aslak Grinsted  (Feel free to modify this code.)
% 2014 / Mark Shein-Idelson - add the option to plot axes on a parent handle
f=gcf;

Args=[];
UserDataArgsOK=0;
Args=get(f,'UserData');
if isstruct(Args) 
    UserDataArgsOK=isfield(Args,'SpacingHorizontal')&isfield(Args,'Holdaxis')&isfield(Args,'rows')&isfield(Args,'cols');
end
OKToStoreArgs=isempty(Args)|UserDataArgsOK;

if isempty(Args)&(~UserDataArgsOK)
    Args=struct('Holdaxis',0, ...
        'SpacingVertical',0.05,'SpacingHorizontal',0.05, ...
        'PaddingLeft',0,'PaddingRight',0,'PaddingTop',0,'PaddingBottom',0, ...
        'MarginLeft',.1,'MarginRight',.1,'MarginTop',.1,'MarginBottom',.1, ...
        'rows',[],'cols',[]); 
end
Args=parseArgs(varargin,Args,{'Holdaxis'},{'Spacing' {'sh','sv'}; 'Padding' {'pl','pr','pt','pb'}; 'Margin' {'ml','mr','mt','mb'}});

if ishghandle(Args.NumericArguments{1}) %if a parent handle is given in input
    hParent=Args.NumericArguments{1};
    Args.NumericArguments=Args.NumericArguments(2:end);
else
    hParent=f;
end
if (length(Args.NumericArguments)>1)
    Args.rows=Args.NumericArguments{1};
    Args.cols=Args.NumericArguments{2};
%remove these 2 numerical arguments
    Args.NumericArguments={Args.NumericArguments{3:end}};
end

if OKToStoreArgs
    set(f,'UserData',Args);
end


switch length(Args.NumericArguments)
   case 0
       return % no arguments but rows/cols.... 
   case 1
      x1=mod((Args.NumericArguments{1}-1),Args.cols)+1; x2=x1;
      y1=floor((Args.NumericArguments{1}-1)/Args.cols)+1; y2=y1;
   case 2
      x1=Args.NumericArguments{1};x2=x1;
      y1=Args.NumericArguments{2};y2=y1;
   case 4
      x1=Args.NumericArguments{1};x2=x1+Args.NumericArguments{3}-1;
      y1=Args.NumericArguments{2};y2=y1+Args.NumericArguments{4}-1;
   otherwise
      error('subaxis argument error')
end
    

cellwidth=((1-Args.MarginLeft-Args.MarginRight)-(Args.cols-1)*Args.SpacingHorizontal)/Args.cols;
cellheight=((1-Args.MarginTop-Args.MarginBottom)-(Args.rows-1)*Args.SpacingVertical)/Args.rows;
xpos1=Args.MarginLeft+Args.PaddingLeft+cellwidth*(x1-1)+Args.SpacingHorizontal*(x1-1);
xpos2=Args.MarginLeft-Args.PaddingRight+cellwidth*x2+Args.SpacingHorizontal*(x2-1);
ypos1=Args.MarginTop+Args.PaddingTop+cellheight*(y1-1)+Args.SpacingVertical*(y1-1);
ypos2=Args.MarginTop-Args.PaddingBottom+cellheight*y2+Args.SpacingVertical*(y2-1);

if Args.Holdaxis
    h=axes('position',[xpos1 1-ypos2 xpos2-xpos1 ypos2-ypos1],'Parent',hParent);
else
    h=subplot('position',[xpos1 1-ypos2 xpos2-xpos1 ypos2-ypos1],'Parent',hParent);
end


set(h,'box','on');
%h=axes('position',[x1 1-y2 x2-x1 y2-y1]);
set(h,'units',get(gcf,'defaultaxesunits'));
set(h,'tag','subaxis');


if (nargout==0) 
    clear h; 
end

function ArgStruct=parseArgs(args,ArgStruct,varargin)
% Helper function for parsing varargin. 
%
%
% ArgStruct=parseArgs(varargin,ArgStruct[,FlagtypeParams[,Aliases]])
%
% * ArgStruct is the structure full of named arguments with default values.
% * Flagtype params is params that don't require a value. (the value will be set to 1 if it is present)
% * Aliases can be used to map one argument-name to several argstruct fields
%
%
% example usage: 
% --------------
% function parseargtest(varargin)
%
% %define the acceptable named arguments and assign default values
% Args=struct('Holdaxis',0, ...
%        'SpacingVertical',0.05,'SpacingHorizontal',0.05, ...
%        'PaddingLeft',0,'PaddingRight',0,'PaddingTop',0,'PaddingBottom',0, ...
%        'MarginLeft',.1,'MarginRight',.1,'MarginTop',.1,'MarginBottom',.1, ...
%        'rows',[],'cols',[]); 
%
% %The capital letters define abrreviations.  
% %  Eg. parseargtest('spacingvertical',0) is equivalent to  parseargtest('sv',0) 
%
% Args=parseArgs(varargin,Args, ... % fill the arg-struct with values entered by the user
%           {'Holdaxis'}, ... %this argument has no value (flag-type)
%           {'Spacing' {'sh','sv'}; 'Padding' {'pl','pr','pt','pb'}; 'Margin' {'ml','mr','mt','mb'}});
%
% disp(Args)
%
%
%
%
% % Aslak Grinsted 2003

Aliases={};
FlagTypeParams='';

if (length(varargin)>0) 
    FlagTypeParams=strvcat(varargin{1});
    if length(varargin)>1
        Aliases=varargin{2};
    end
end
 

%---------------Get "numeric" arguments
NumArgCount=1;
while (NumArgCount<=size(args,2))&(~ischar(args{NumArgCount}))
    NumArgCount=NumArgCount+1;
end
NumArgCount=NumArgCount-1;
if (NumArgCount>0)
    ArgStruct.NumericArguments={args{1:NumArgCount}};
else
    ArgStruct.NumericArguments={};
end 


%--------------Make an accepted fieldname matrix (case insensitive)
Fnames=fieldnames(ArgStruct);
for i=1:length(Fnames)
    name=lower(Fnames{i,1});
    Fnames{i,2}=name; %col2=lower
    AbbrevIdx=find(Fnames{i,1}~=name);
    Fnames{i,3}=[name(AbbrevIdx) ' ']; %col3=abreviation letters (those that are uppercase in the ArgStruct) e.g. SpacingHoriz->sh
    %the space prevents strvcat from removing empty lines
    Fnames{i,4}=isempty(strmatch(Fnames{i,2},FlagTypeParams)); %Does this parameter have a value? (e.g. not flagtype)
end
FnamesFull=strvcat(Fnames{:,2});
FnamesAbbr=strvcat(Fnames{:,3});

if length(Aliases)>0  
    for i=1:length(Aliases)
        name=lower(Aliases{i,1});
        FieldIdx=strmatch(name,FnamesAbbr,'exact'); %try abbreviations (must be exact)
        if isempty(FieldIdx) 
            FieldIdx=strmatch(name,FnamesFull); %&??????? exact or not? 
        end
        Aliases{i,2}=FieldIdx;
        AbbrevIdx=find(Aliases{i,1}~=name);
        Aliases{i,3}=[name(AbbrevIdx) ' ']; %the space prevents strvcat from removing empty lines
        Aliases{i,1}=name; %dont need the name in uppercase anymore for aliases
    end
    %Append aliases to the end of FnamesFull and FnamesAbbr
    FnamesFull=strvcat(FnamesFull,strvcat(Aliases{:,1})); 
    FnamesAbbr=strvcat(FnamesAbbr,strvcat(Aliases{:,3}));
end

%--------------get parameters--------------------
l=NumArgCount+1; 
while (l<=length(args))
    a=args{l};
    if ischar(a)
        paramHasValue=1; % assume that the parameter has is of type 'param',value
        a=lower(a);
        FieldIdx=strmatch(a,FnamesAbbr,'exact'); %try abbreviations (must be exact)
        if isempty(FieldIdx) 
            FieldIdx=strmatch(a,FnamesFull); 
        end
        if (length(FieldIdx)>1) %shortest fieldname should win 
            [mx,mxi]=max(sum(FnamesFull(FieldIdx,:)==' ',2));
            FieldIdx=FieldIdx(mxi);
        end
        if FieldIdx>length(Fnames) %then it's an alias type.
            FieldIdx=Aliases{FieldIdx-length(Fnames),2}; 
        end
        
        if isempty(FieldIdx) 
            error(['Unknown named parameter: ' a])
        end
        for curField=FieldIdx' %if it is an alias it could be more than one.
            if (Fnames{curField,4})
                val=args{l+1};
            else
                val=1; %parameter is of flag type and is set (1=true)....
            end
            ArgStruct.(Fnames{curField,1})=val;
        end
        l=l+1+Fnames{FieldIdx(1),4}; %if a wildcard matches more than one
    else
        error(['Expected a named parameter: ' num2str(a)])
    end
end