Output data to new text file for every time step

where should I put my printf's that for the current time steps that I have, I get 5 new files for each step with the x,y,z positions contained in them?

 dt=5*10e-5;
  for t=0:dt:4*dt %99 for 100 graphs
      figure;
      for ind=1:1920
      U=(3*ind+linspace(1,3,3)-3);
      Phi= PHI_disp_RBME_ModePlot_N(U);
      r=xlocs_full(ind);
      omega=(f_disp_RBME(iMode,kPtMode)*2*pi);
      k=kappa_space(kPtMode);
      spatialphase=k*r;
      timephase=omega*t;
      displ=Phi*exp(i*((spatialphase)-(timephase)));
      xOvito(ind)=xOvito(ind)+magFact*displ(1);
      yOvito(ind)=yOvito(ind)+magFact*displ(2);
      zOvito(ind)=zOvito(ind)+magFact*displ(3);
      end
      header1= 'id';
      header2= 'type';
      header3='x';
      header4='y';
      header5='z';
      fid=fopen('Dumped.txt','w');
      %fprintf(fid, [header 1 ' ' header 2 ' ' header 3 ' ' header 4 ' ' header 5 ' '\n']);
      fprintf(fid, [ header1 ' ' header2 ' ' header3 ' ' header4 ' ' header5 '\n']);
      fprintf(fid, '%f %f %f \n', [xOvito yOvito zOvito]');
      fclose(fid);
      plot3(xOvito,yOvito,zOvito,'ko','markerfacecolor','r', 'markersize', 7);
      xrotation = 0;
      yrotation = 0;
      view(xrotation, yrotation);
      xlabel('x')
      ylabel('y')
      zlabel('z')
      axis equal
      xview=0;
      yview=0;
      view(xview,yview);
  end

After looking at my code, I see that each time I rewrite the text file, so I only have the last time step's data. How do I change this?

[Krish Desai]

Tried to use sprintf, only created one file....

%TimeStep
%kPtMode=3;
%iMode=6;
dt=5*10e-5;
steps=4;
for t=0:dt:steps*dt %99 for 100 graphs
    figure;
    for ind=1:1920
    U=(3*ind+linspace(1,3,3)-3);
    Phi= PHI_disp_RBME_ModePlot_N(U);
    r=xlocs_full(ind);
    omega=(f_disp_RBME(iMode,kPtMode)*2*pi);
    k=kappa_space(kPtMode);
    spatialphase=k*r;
    timephase=omega*t;
    displ=Phi*exp(i*((spatialphase)-(timephase)));
    xOvito(ind)=xOvito(ind)+magFact*displ(1);
    yOvito(ind)=yOvito(ind)+magFact*displ(2);
    zOvito(ind)=zOvito(ind)+magFact*displ(3);
    end
    plot3(xOvito,yOvito,zOvito,'ko','markerfacecolor','r', 'markersize', 7);
    xrotation = 0;
    yrotation = 0;
    view(xrotation, yrotation);
    xlabel('x')
    ylabel('y')
    zlabel('z')
    axis equal
    xview=0;
    yview=0;
    view(xview,yview);
    header1= 'id';
    header2= 'type';
    header3='x';
    header4='y';
    header5='z';
    filename=sprintf('%s_%d','filename',i);
    fid=fopen(filename,'w');
    %fprintf(fid, [header 1 ' ' header 2 ' ' header 3 ' ' header 4 ' ' header 5 ' '\n']);
    fprintf(fid, [ header1 ' ' header2 ' ' header3 ' ' header4 ' ' header5 '\n']);
    fprintf(fid, '%f %f %f \n', [xOvito yOvito zOvito]');
    fclose(fid);
end

end

[Walter Roberson]

You do not initialize or change i, so it is going to have its default value as sqrt(-1)

[Krish Desai]

What should I change i to? What is supposed to be there?

Answer 1

[Vidya Viswanathan]

Hi Krish,

I believe you are looking for a method to append the data from the next time stamp to the file rather than rewriting it. The function "fopen" provides you with an option to open the file with the appropriate access. To append to the existing file, you would have to open it as follows:

>> fid=fopen(filename,'a');

You could refer to the following documentation page for the same information:

http://www.mathworks.com/help/matlab/ref/fopen.html?searchHighlight=fopen#inputarg_permission

I hope this answers your question.

Regards,

Vidya