'%' means the start of a comment

  name = 'test_low_freq17';
  filename='';%in case you want to add something else onto the file name besides what's stored in 'name'
  dxfname=strcat(filename,name,'.dxf');
  [fid,err]=DXF_start(dxfname,1); %the opening of the file starts in DXF_start
  xbias = 0; %xbias is the spacing between a whole set of  transducers and another set of transducers
  DmakeDevice_1Tgrating(150,50,80,2500,fid,xbias,'test_low_freq17')
  xbias = 16000;
  DmakeDevice_1Tgrating(200,100,80,2500,fid,xbias,'test_low_freq17')
  xbias = xbias + 16000;
  DmakeDevice_1Tgrating(400,200,80,2500,fid,xbias,'test_low_freq17')
  DXF_end(fid) %where the dxf file is written
  

  function out=DmakeDevice_1Tgrating(startf,stopf,xscale,yscale,fid,xbias,name)
  %units are inches in cad and microns in final program
  lambda=633e-9;
  n_e=2.3;
  % start center stop frequency
  vxeff=3960;%effective velocities from experimental data (accounting for reflection)
  vyeff=4500;
  vy=3909; %freespace velocity
  FV1=[430,490]*1e6;
  %freq=120;
   FH1=[startf,stopf]*1e6;
   FH2=[150,150]*1e6;
   FH3=[200,200]*1e6;
   FH4=[250,250]*1e6;
   FH5=[300,300]*1e6;
   FH6=[400,400]*1e6;
   FH7=[500,500]*1e6;
   FH8=[600,600]*1e6;
   FH9=[700,700]*1e6;
   FH10=[800,800]*1e6;
  Fcomb=[FH1;FH2;FH3;FH4;FH5;FH6;FH7;FH8;FH9;FH10];
  Fc=(Fcomb(:,1)+Fcomb(:,2))./2;
  Bragg=asind(lambda*Fc./(2*vy*n_e));
  biasf=700*1e6;
  biasb=asind(lambda*biasf./(2*vy*n_e));
  bias_offset=2*biasb;
  Bragg=bias_offset-Bragg;
  %make a bias at
  startl=vy./(4*Fcomb(:,1));
  startl=startl*1e6;
  vstartl=vxeff./(4*FV1(1));
  vstartl=vstartl*1e6;
  stopl=vy./(4*Fcomb(:,2));
  stopl=stopl*1e6;
  vstopl=vxeff./(4*FV1(2));
  vstopl=vstopl*1e6;
  startl
  stopl
  sense='c'; %clockwise for 'c', counterclockwise for 'cc'
  vertex='tr';
  %N=200;
  %xscale=100;
  paddim=10; %this is the length and width of the pad?
  buswidth=10;
  %yscale=2000;
  ydim=yscale/4;%period size
  %fprintf(fid,'****HCHIRP DATA**** \n sense %s\n vertex %s\n xscale %g\n paddim %g\n buswidth %g\n ',sense,vertex,xscale, paddim, buswidth);
  HTnum=size(Fcomb(:,1));
  for index=1:1%HTnum %NUMBER OF ROWS, why does it make the 2nd row offset to the left?
     % DXFTRYgrating(fid,sense,vertex, N,xscale,Bragg(index),startl(index),stopl(index),paddim,buswidth,index);
  N=round(ydim/mean([startl(index),stopl(index)]));
   %N=100;%************************************************Change THIS***************  
     DXFTRYgrating(xbias,fid,sense,vertex, N,xscale,90',startl(index),stopl(index),paddim,buswidth,index); %do i need the apostrophy after theta?
  end
  end
  

  function out=Dmakerect(sense,vertex)
  %returns a box expressed as a 2xN matrix of coors starting at the specified
  %vertex: tr, tl, br, bl
  %and drawn in the given sense: c, cc etc.
  %canonx=[0,0,1,1]; %clockwise bottom left
  %canony=[0,1,1,0];
  canonx=[0,0,250,250]; %this is for the wirebonding pads/busses %250 makes it 2500um long, 3 makes 30um high
  canony=[0,9,9,0];
  canoncoors=[canonx;canony];
  %********Starting Point and Sense*******
  switch vertex
     case {'tr','topright'}
        if sense=='clockwise'|'c'| 'clk' | 'clock'
          canoncoors=circshift(canoncoors,[1,2]);
          canoncoors=[canoncoors,canoncoors(:,1)];%first point becomes last point
        else
          canoncoors=circshift(fliplr(canoncoors),[1,1]);
          canoncoors=[canoncoors,canoncoors(:,1)];%first point becomes last point
        end
        %disp('start top right')
     case {'tl','topleft'}
        if sense=='clockwise'|'c'|'clk' | 'clock'
          canoncoors=circshift(canoncoors,[1,1]);
          canoncoors=[canoncoors,canoncoors(:,1)];%first point becomes last point
        else
          canoncoors=circshift(fliplr(canoncoors),[1,2]);
          canoncoors=[canoncoors,canoncoors(:,1)];%first point becomes last point
        end
        %disp('start top left')
     case {'br','bottomright'}
        if sense=='clockwise'|'c'|'clk' | 'clock'
          canoncoors=circshift(canoncoors,[1,3]);
          canoncoors=[canoncoors,canoncoors(:,1)];%first point becomes last point
        else
          canoncoors=circshift(fliplr(canoncoors),[1,0]);
          canoncoors=[canoncoors,canoncoors(:,1)];%first point becomes last point
        end
        %disp('start bottorm right')
     case {'bl','bottomleft'}
        if sense=='clockwise'|'c'|'clk' | 'clock'
          canoncoors=circshift(canoncoors,[1,0]);
          canoncoors=[canoncoors,canoncoors(:,1)];%first point becomes last point
        else
          canoncoors=circshift(fliplr(canoncoors),[1,3]);
          canoncoors=[canoncoors,canoncoors(:,1)];%first point becomes last point
        end
        %disp('start bottom left')
  end
  %********
  out=canoncoors;