dfield7.m

matlab of linear system

	  end
	  pstring{kk} = [pname{kk},' = ', tp1str];
	end
      end
      
      % Get ready to do some error trapping.
      
      SS = warning;
      warning off
      XxXxXx = WINvect(1) + rand*(WINvect(2)-WINvect(1));
      TtTtTt = WINvect(3) + rand*(WINvect(4)-WINvect(3));
      err = 0;
      
      % Now we remove the backslashes (\) used to get Greek into the
      % labels. 
      txname = Xname;
      ttname = Tname;   
      derivstr(find(abs(derivstr)==92))=[];
      Xname(find(abs(Xname)==92))=[];
      Tname(find(abs(Tname)==92))=[];
      
      eval([Xname,'=XxXxXx;'],'err = 1;');
      if err
	errmsg = ['"',xstr, '" is not a valid variable name in MATLAB.'];
	fprintf('\a')
	errordlg(errmsg,'dfield7 error','on');
	warning(SS)
	return
      end
      err = 0;
      eval([Tname,'=TtTtTt;'],'err = 1;');
      if err
	errmsg = ['"',tstr, '" is not a valid variable name in MATLAB.'];
	fprintf('\a')
	errordlg(errmsg,'dfield7 error','on');
	warning(SS)
	return
      end
      
      
      % Replace the parameters/expressions with their values.
      
      pflag = zeros(1,4);
      perr = [];
      pnameh = sud.h.pname;
      pvalh = sud.h.pval;
      for kk = 1:4;
	pn = char(get(pnameh(kk),'string'));
	pn(find(abs(pn)==92))=[];
	pv = char(get(pvalh(kk),'string'));
	if ~isempty(pn)
	  if isempty(pv) 
	    perr = pvalh(kk);
	  else 
	    if isempty(str2num(pv)) % This is an expression.
	      tpv = pv;
	      tpv(find(abs(tpv)==92))=[];
	      err = 0; pval = '';
	      eval(['pval = ',tpv,';'],'err=1;');   %pval;
	      if (err | isempty(pval))
		errmsg = ['The expression for ',pn,' is not valid.'];
		fprintf('\a')
		errordlg(errmsg,'dfield7 error','on');
		warning(SS)
		return
	      end
	    end
	    xderivstr = dfield7('paraeval',pn,pv,derivstr);
	    if ~strcmp(xderivstr,derivstr)
	      pflag(kk) = 1;
	      derivstr = xderivstr;
	    end
	  end
	end
      end
      
      % We have to make the derivative strings array smart.
      
      l = length(derivstr);
      for (k=fliplr(find((derivstr=='^')|(derivstr=='*')|(derivstr=='/'))))
	derivstr = [derivstr(1:k-1) '.' derivstr(k:l)];
	l = l+1;
      end
      
      % Some more error trapping.
      
      eval(['res = ',derivstr, ';'],'err = 1;');
      if err | isempty(res)
	if isempty(perr)
          errmsg = ['The differential equation ',...
		    'is not entered correctly.'];
	else
          errstr1 = 'The differential equation does not evaluate correctly.';
          errstr2 = 'At least one of the parameter values is not a number.';
          errmsg = str2mat(errstr1,errstr2);
          set(perr,'string','?');
	end
	fprintf('\a')
	errordlg(errmsg,'dfield7 error','on');
	dfield7('restart');
	warning(SS);
	return
      end
      warning(SS);
      
      % Build a new derivative m-file.
      
      tee = clock;
      tee = ceil(tee(6)*100);
      dfcn=['dftp',num2str(tee)];
      fcnstr = ['function YYyYypr = ',dfcn,'(TtTt,YyYy)\n\n'];
      commstr = '%%%% Created by dfield7\n\n';
      varstr = [Xname,' = YyYy;', Tname,' = TtTt;\n\n'];
      lenstr = ['l = length(YyYy);\n'];
      derstr1 = ['YYyYypr = ', derivstr,';\n'];
      derstr2 = ['if (length(YYyYypr) < l) YYyYypr = YYyYypr*ones(1,l);end\n'];
      
      dff = fopen([tempdir,dfcn,'.m'],'w');
      fprintf(dff,fcnstr);
      fprintf(dff,commstr);
      fprintf(dff,varstr);
      fprintf(dff,lenstr);
      fprintf(dff,derstr1);
      fprintf(dff,derstr2);
      fclose(dff);
      
      
      % Find dfield7 Display if it exists.	
      % If dfield7 Display exists, update it.  If it does not build it.
      
      dfdisp = findobj('name','dfield7 Display');
      if (~isempty(dfdisp))
	figure(dfdisp);
	dud = get(dfdisp,'user');
	dud.syst = sud.c;
	dud.settings = sud.settings;
	dfcnn = dud.function;
	  if exist(dfcnn) == 2
	    delete([tempdir,dfcnn,'.m'])
	  end
	  
      else
	dfdisp = figure('name','dfield7 Display',...
			'numb','off','interrupt','on',...
			'visible','off','tag','dfield7');
	dfield7('figdefault',dfdisp);
	dud = get(dfdisp,'user');	
	dud.syst = sud.c;
	dud.settings = sud.settings;
	fs = dud.fontsize;
	ssize = dud.ssize;
	r = ssize/10;
	dfaxw = 437*1.2;	% Default axes width
	dfaxh = 315*1.2;	% Default axes height
	dfaxl = 45*1.2;	% Default axes left
	buttw = 40*1.2;     % Default button width
	uni = get(0,'units');
	set(0,'units','pixels');
	ss = get(0,'screensize');
	style = sud.style;
	set(0,'units',uni);
	
	nframeh = 70;   % Default notice frame height
	dfaxb = 4+nframeh+35;
	
	titleh = 30;
	bottomedge = 38;
	dfdh = dfaxh + nframeh + titleh + bottomedge;
	
	sw = ss(3);sh = ss(4);
	bottom = 20;
	
	
	if r*dfdh > sh - bottom -35;
	  r = (sh-bottom-35)/dfdh;
	  fs = 10*r;
	  lw = 0.5*r;
	  set(gcf,'defaultaxesfontsize',fs,'defaultaxeslinewidth',lw);
	  set(gcf,'defaulttextfontsize',fs);
	  set(gcf,'defaultlinelinewidth',lw);
	  set(gcf,'defaultuicontrolfontsize',fs*0.9);
	end
	
	% Set up the bulletin window.
	
	nframe = uicontrol('style','frame','visible','on');
	nstr = {'More';'than';'five';'lines';'of text'};
	dud.notice = uicontrol('style','text',...
			       'horiz','left',...
			       'string',nstr,'visible','on');
	ext = get(dud.notice,'extent');
	nframeh = ext(4)+2;
	
	titleh = r*titleh;
	dfaxl = r*dfaxl;
	buttw = r*buttw;
	butth = fs+20*r;
	
	dfaxw = r*dfaxw;
	dfaxh = r*dfaxh;
	dfaxb = nframeh+r*bottomedge;
	buttl = dfaxl + dfaxw + 5;
	buttsep = (dfaxh - butth)/2;
	
	% Set up the coordinate display
	
	cstr = '(0.9999, 0,9999)';
	dud.ccwind = uicontrol('style','text',...
			       'horiz','left',...
			       'string',cstr,...
			       'visible','on');
	cext = get(dud.ccwind,'extent');
	ccwindtxt = uicontrol('style','text',...
			      'horiz','left',...
			      'string','Cursor position: ',...
			      'visible','on');
	cwh = cext(4);
	cww = cext(3);
	
	% Set up the plot axes.
	
	dud.axes = axes('units','pix',...
			'position',[dfaxl,dfaxb,dfaxw,dfaxh],...
			'next','add',...
			'box','on',...
			'interrupt','on',...
			'xgrid','on',...
			'ygrid','on',...
			'drawmode','fast',...
			'visible','off',...
			'tag','display axes');
	
	% Finish the positions.
	
	dfdw = buttl + buttw +5;
	dfdh = dfaxb+dfaxh+titleh;
	set(nframe,'pos',[10,1,dfdw-20,nframeh]);
	set(dud.notice,'pos',[15,1,dfdw-30,nframeh-2],...
		       'string',{' ';' ';' ';' ';' '});
	
	ctext = get(ccwindtxt,'extent');
	cc1pos = [dfaxl,2+nframeh,ctext(3),cwh];
	cc2pos = [dfaxl+ctext(3),2+nframeh,cww,cwh];
	set(ccwindtxt,'pos',cc1pos);
	set(dud.ccwind,'pos',cc2pos,...
		       'string','');
	dfdleft = max((sw-dfdw)/2,sw-dfdw-60);
	dfdbot = sh - dfdh - 70;
	dfdpos = [dfdleft,dfdbot,dfdw,dfdh];
	set(dfdisp,'resize','on');
	set(dfdisp,'pos',dfdpos);
	
	Arrflag = sud.fieldtype;
	
	% Set up the buttons and the menu.
	
	stopstr = 'aud = get(gca,''user'');aud.stop = 4;set(gca,''user'',aud);';
	
	dbutt(1) = uicontrol('style','push',...
			     'pos',[buttl,dfaxb+2*buttsep,buttw,butth],...
			     'string','Stop',...
			     'call',stopstr,...
			     'vis','off',...
			     'tag','stop');
	
	dbutt(2) = uicontrol('style','push',...
			     'pos',[buttl,dfaxb,buttw,butth],...
			     'string','Quit',...
			     'call','dfield7(''quit'')',...
			     'visible','off');
	
	dbutt(3) = uicontrol('style','push',...
			     'pos',[buttl,dfaxb+buttsep,buttw,butth],...
			     'string','Print',...
			     'call','dfield7(''print'')',...
			     'visible','off');	
      
	dud.butt = dbutt;
	hhsetup = get(0,'showhiddenhandles');
	set(0,'showhiddenhandles','on');
	
	
	% File menu
	
	fmenu = findobj(gcf,'label','&File'); 
	delete(findobj(fmenu,'label','&New Figure'));
	delete(findobj(fmenu,'label','&Open...'));
	delete(findobj(fmenu,'label','&Close'));
	set(findobj(fmenu,'label','&Save'),...
	    'separator','off',...
	    'pos',1);
	set(findobj(fmenu,'label','Save &As...'),...
	    'pos',2);
	delete(findobj(fmenu,'label','Pre&ferences...'));
	set(findobj(fmenu,'label','&Export...'),...
	    'pos',3);
	set(findobj(fmenu,'label','Pa&ge Setup...'),'pos',4,...
			  'separator','on');
	set(findobj(fmenu,'label','Print Pre&view...'),'pos',5);
	set(findobj(fmenu,'label','Print Set&up...'),'pos',6);
	set(findobj(fmenu,'label','&Print...'),'pos',7);
	merestart = uimenu(fmenu,'label','Restart dfield7','call',...
			   'dfield7(''restart'')','separator','on','pos',8);
	
	mequit = uimenu(fmenu,'label','Quit dfield7',...
			'call','dfield7(''quit'')','separator','on');
	
	% Tools menu
	
	tmenu = findobj(gcf,'label','&Tools'); 
	delete(tmenu);
	
	% Insert menu
	
	imenu = findobj(gcf,'label','&Insert');
	inschild = get(imenu,'child');
	legitem = findobj(inschild,'label','&Legend');
	colitem = findobj(inschild,'label','&Colorbar');
	delete([legitem,colitem]);
	
	
	% Edit menu
	
	emenu = findobj(gcf,'label','&Edit'); 
	menu(2) = uimenu(emenu,'label','Zoom in.',...
			 'call','dfield7(''zoomin'')',...
			 'pos',1);
	
	zbmenu = uimenu(emenu,'label','Zoom back.',...
			'call','dfield7(''zoomback'')',...
			'enable','off',...
			'tag','zbmenu',...
			'pos',2);
	
	metext = uimenu(emenu,'label','Enter text on the Display Window.',...
			'call','dfield7(''text'')',...
			'separator','on',...
			'pos',3);
	
	medel = uimenu(emenu,'label','Delete a graphics object.',...
		       'call','dfield7(''delete'')',...
		       'visible','on',...
		       'pos',4);
	medall = uimenu(emenu,'label','Erase all solutions.',...
			'call','dfield7(''dallsol'')',...
			'separator','off',...
			'pos',5);
	
	medalllev = uimenu(emenu,'label','Erase all level curves.',...
			   'call','dfield7(''dalllev'')',...
			   'separator','off',...
			   'pos',6);
	
	medall = uimenu(emenu,'label','Erase all graphics objects.',...
			'call','dfield7(''dall'')',...
			'separator','off',...
			'pos',7);
	
	set(findobj(emenu,'label','&Undo'),'separator','on',...
			  'pos',8);
	set(findobj(emenu,'label','Cu&t'),'pos',9);
	set(findobj(emenu,'label','&Copy'),'pos',10);
	set(findobj(emenu,'label','&Paste'),'pos',11);
	set(findobj(emenu,'label','&Select All'),'pos',12);
	set(findobj(emenu,'label','Copy &Figure'),'pos',13);
	set(findobj(emenu,'label','Copy &Options'),'pos',14);
	set(findobj(emenu,'label','F&igure Properties'),'pos',15);
	set(findobj(emenu,'label','&Axes Properties'),'pos',16);
	set(findobj(emenu,'label','C&urrent Object Properties'),'pos',17);
	
	% Options menu
	
	menu(1) = uimenu('label','Options','visible','off','pos',3);
	
	menukey = uimenu(menu(1),'label','Keyboard input.','call',...
			 'dfield7(''kbd'')');
	
	mesev   = uimenu(menu(1),'label','Plot several solutions.',...
			 'call','dfield7(''several'')');
	
	menulevel = uimenu(menu(1),'label','Plot level curves.',...
			   'call','dfield7(''level'')',...
			   'separator','off','tag','level');
	
	meexportdata = uimenu(menu(1),'label','Export solution data.',...
			      'call','dfield7(''export'')',...
			      'separator','off','tag','dexp');
	
	plcall = [
	    'ud = get(gcf,''user'');',...
	    'me = gcbo;',...
	    'label = get(me,''label'');',...  
	    'if strcmp(label,''Show the phase line.''),',...
	    '  set(me,''label'',''Hide the phase line.'');',...
	    '  ud.pline = ''on'';',...
	    '  set(ud.plineh,''vis'',''on'');',...	  
	    '  set(gcf,''user'',ud);',...
	    'else,',...
	    '  set(me,''label'',''Show the phase line.'');',...
	    '  ud.pline = ''off'';',...
	    '  set(ud.plineh,''vis'',''off'');',...	  
	    '  kk = find(ishandle(ud.plhand));',...	  
	    '  delete(ud.plhand(kk));',...
	    '  ud.plhand = [];',...	  
	    '  set(gcf,''user'',ud);',...
	    'end'];  
	
	mepline = uimenu(menu(1),'label','Show the phase line.',...
			 'call',plcall,'tag','pline','separator','on');	  
	
	mesolvset = uimenu(menu(1),'label','Solver settings.',...
			   'call','dfield7(''solvset'')');
	mesolve = uimenu(menu(1),'label','Solver.');
	
	solverstr = ['ud = get(gcf,''user'');',...
		     'me = gcbo;',...
		     'meud = get(me,''user'');',...
		     'ud.settings.refine = meud.refine;',...
		     'ud.settings.tol = meud.tol;',...
		     'ud.settings.solver = meud.solver;',...
		     'ud.settings.solvhandle = meud.solvhandle;',...
		     'ud.settings.stepsize = meud.stepsize;',...
		     'ud.settings.hmax = meud.hmax;',...
		     'set(ud.solver,''checked'',''off'');',...
		     'set(me,''checked'',''on'');',...
		     'set(gcf,''user'',ud);',...
		     'dfset = findobj(''name'',''dfield7 Setup'');',...
		     'sud = get(dfset,''user'');',...
		     'sud.settings = ud.settings;',...
		     'set(dfset,''user'',sud);',...
		     'dfield7(''solvset'');'];
	solver = dud.settings.solver;
	dpset.refine = 4;
	dpset.tol = 1e-6;
	dpset.solver = 'Dormand-Prince';
	dpset.solvhandle = @dfdp45;
	dpset.stepsize = 0;
	dpset.hmax = 0;
	if strcmp(solver,'Dormand-Prince')
	  dpch = 'on';
	else
	  dpch = 'off';
	end
	
	eulset.refine = 1;
	eulset.tol = 0;
	eulset.solver = 'Euler';
	eulset.solvhandle = @dfeul;
	eulset.stepsize = 0.1;
	eulset.hmax = 0;
	if strcmp(solver,'Euler')
	  eulch = 'on';