diff options
| -rw-r--r-- | Readme.md | 13 | ||||
| -rw-r--r-- | demos/Demo1.m | 34 | ||||
| -rw-r--r-- | main_func/FISTA_REC.m | 33 | ||||
| -rw-r--r-- | supp/add_wedges.m | 35 | ||||
| -rw-r--r-- | supp/filtersinc.m | 28 | ||||
| -rw-r--r-- | supp/ssim_index.m | 181 | ||||
| -rw-r--r-- | supp/subplot_tight.m | 1 | 
7 files changed, 29 insertions, 296 deletions
| @@ -1,4 +1,4 @@ -# FISTA Reconstruction (Daniil Kazanteev) +# FISTA Reconstruction (Daniil Kazantsev)  # General Description @@ -14,7 +14,6 @@ Software for reconstructing 2D/3D x-ray and neutron tomography datasets. The dat  ### Demos:   * Demo1: Synthetic phantom reconstruction with noise, stripes and zingers - * Demo2: Synthetic phantom reconstruction with noise, stripes, zingers, and the missing wedges   * DemoRD1: Real data reconstruction from  sino_basalt.mat (see Data)   * DemoRD2: Real data reconstruction from  sino3D_dendrites.mat (see Data) @@ -26,7 +25,7 @@ Software for reconstructing 2D/3D x-ray and neutron tomography datasets. The dat  ### Main modules:    * FISTA_REC.m – Matlab function to perform FISTA-based reconstruction -  * FISTA_TV.c – C-omp function to solve for the weighted TV term using FISTA +  * FGP_TV.c – C-omp function to solve for the weighted TV term using FGP    * SplitBregman_TV.c – C-omp function to solve for the weighted TV term using Split-Bregman    * LLT_model.c – C-omp function to solve for the weighted LLT [3] term using explicit scheme    * studentst.m – Matlab function to calculate Students t penalty with 'auto-tuning' @@ -34,17 +33,13 @@ Software for reconstructing 2D/3D x-ray and neutron tomography datasets. The dat  ### Supplementary:   * zing_rings_add.m Matlab script to generate proj. data, add noise, zingers and stripes - * add_wedges.m script to add the missing wedge to existing sinogram - * my_red_yellowMAP.mat – nice colormap for the phantom +  * my_red_yellowMAP.mat – nice colormap for the phantom   * RMSE.m – Matlab function to calculate Root Mean Square Error - * subplot_tight – visualizing better subplots - * ssim_index – ssim calculation - +   ### Practical advices:   * Full 3D reconstruction provides much better results than 2D. In the case of ring artifacts, 3D is almost necessary   * Depending on data it is better to use TV-LLT combination in order to achieve piecewise-smooth solution. The  DemoRD2 shows one possible example when smoother surfaces required.   * L (Lipshitz constant) if tweaked can lead to faster convergence than automatic values - * Convergence is normally much faster when using Fourier filtering before backprojection   * Students’t penalty is generally quite stable in practice, however some tweaking of L might require for the real data   * You can choose between SplitBregman-TV and FISTA-TV modules. The former is slower but requires less  memory (for 3D volume U it can take up to 6 x U), the latter is faster but can take more memory (for 3D volume U it can take up to 11 x U). Also the SplitBregman is quite good in improving contrast.  diff --git a/demos/Demo1.m b/demos/Demo1.m index 486b97c..3d57795 100644 --- a/demos/Demo1.m +++ b/demos/Demo1.m @@ -19,7 +19,7 @@ addpath('../main_func/');  addpath('../supp/'); 
  load phantom_bone512.mat % load the phantom
 -load  my_red_yellowMAP.mat % load the colormap
 +load my_red_yellowMAP.mat % load the colormap
  % load sino1.mat; % load noisy sinogram
  N = 512; %  the size of the tomographic image NxN
 @@ -67,12 +67,12 @@ error_FISTA = output.Resid_error; obj_FISTA = output.objective;  figure(2); clf
  %set(gcf, 'Position', get(0,'Screensize'));
 -subplot_tight(1,2,1, [0.05 0.05]); imshow(X_FISTA,[0 0.6]); title('FISTA-PWLS reconstruction'); colorbar;
 -subplot_tight(1,2,2, [0.05 0.05]); imshow((phantom - X_FISTA).^2,[0 0.1]);  title('residual'); colorbar;
 +subplot(1,2,1, [0.05 0.05]); imshow(X_FISTA,[0 0.6]); title('FISTA-PWLS reconstruction'); colorbar;
 +subplot(1,2,2, [0.05 0.05]); imshow((phantom - X_FISTA).^2,[0 0.1]);  title('residual'); colorbar;
  colormap(cmapnew); 
  figure(3); clf
 -subplot_tight(1,2,1, [0.05 0.05]); plot(error_FISTA);  title('RMSE plot'); colorbar;
 -subplot_tight(1,2,2, [0.05 0.05]); plot(obj_FISTA);  title('Objective plot'); colorbar;
 +subplot(1,2,1, [0.05 0.05]); plot(error_FISTA);  title('RMSE plot'); colorbar;
 +subplot(1,2,2, [0.05 0.05]); plot(obj_FISTA);  title('Objective plot'); colorbar;
  colormap(cmapnew); 
  %%
  fprintf('%s\n', 'Reconstruction using FISTA-PWLS-TV...');
 @@ -94,12 +94,12 @@ fprintf('%s %.4f\n', 'Min RMSE for FISTA-PWLS-TV reconstruction is:', min(error_  error_FISTA_TV = output.Resid_error; obj_FISTA_TV = output.objective;
  figure(4); clf
 -subplot_tight(1,2,1, [0.05 0.05]); imshow(X_FISTA_TV,[0 0.6]); title('FISTA-PWLS-TV reconstruction'); colorbar;
 -subplot_tight(1,2,2, [0.05 0.05]); imshow((phantom - X_FISTA_TV).^2,[0 0.1]);  title('residual'); colorbar;
 +subplot(1,2,1, [0.05 0.05]); imshow(X_FISTA_TV,[0 0.6]); title('FISTA-PWLS-TV reconstruction'); colorbar;
 +subplot(1,2,2, [0.05 0.05]); imshow((phantom - X_FISTA_TV).^2,[0 0.1]);  title('residual'); colorbar;
  colormap(cmapnew); 
  figure(5); clf
 -subplot_tight(1,2,1, [0.05 0.05]); plot(error_FISTA_TV);  title('RMSE plot'); colorbar;
 -subplot_tight(1,2,2, [0.05 0.05]); plot(obj_FISTA_TV);  title('Objective plot'); colorbar;
 +subplot(1,2,1, [0.05 0.05]); plot(error_FISTA_TV);  title('RMSE plot'); colorbar;
 +subplot(1,2,2, [0.05 0.05]); plot(obj_FISTA_TV);  title('Objective plot'); colorbar;
  colormap(cmapnew); 
  %%
  fprintf('%s\n', 'Reconstruction using FISTA-GH-TV...');
 @@ -123,13 +123,13 @@ fprintf('%s %.4f\n', 'Min RMSE for FISTA-GH-TV reconstruction is:', min(error_FI  error_FISTA_GH_TV = output.Resid_error; obj_FISTA_GH_TV = output.objective;
  figure(6); clf
 -subplot_tight(1,2,1, [0.05 0.05]); imshow(X_FISTA_GH_TV,[0 0.6]); title('FISTA-GH-TV reconstruction'); colorbar;
 -subplot_tight(1,2,2, [0.05 0.05]);imshow((phantom - X_FISTA_GH_TV).^2,[0 0.1]);  title('residual'); colorbar;
 +subplot(1,2,1, [0.05 0.05]); imshow(X_FISTA_GH_TV,[0 0.6]); title('FISTA-GH-TV reconstruction'); colorbar;
 +subplot(1,2,2, [0.05 0.05]);imshow((phantom - X_FISTA_GH_TV).^2,[0 0.1]);  title('residual'); colorbar;
  colormap(cmapnew); 
  figure(7); clf
 -subplot_tight(1,2,1, [0.05 0.05]);  plot(error_FISTA_GH_TV);  title('RMSE plot'); colorbar;
 -subplot_tight(1,2,2, [0.05 0.05]);  plot(obj_FISTA_GH_TV);  title('Objective plot'); colorbar;
 +subplot(1,2,1, [0.05 0.05]);  plot(error_FISTA_GH_TV);  title('RMSE plot'); colorbar;
 +subplot(1,2,2, [0.05 0.05]);  plot(obj_FISTA_GH_TV);  title('Objective plot'); colorbar;
  colormap(cmapnew); 
  %%
  fprintf('%s\n', 'Reconstruction using FISTA-Student-TV...');
 @@ -155,13 +155,13 @@ error_FISTA_student_TV = output.Resid_error; obj_FISTA_student_TV = output.objec  figure(8); 
  set(gcf, 'Position', get(0,'Screensize'));
 -subplot_tight(1,2,1, [0.05 0.05]); imshow(X_FISTA_student_TV,[0 0.6]); title('FISTA-Student-TV reconstruction'); colorbar;
 -subplot_tight(1,2,2, [0.05 0.05]); imshow((phantom - X_FISTA_student_TV).^2,[0 0.1]);  title('residual'); colorbar;
 +subplot(1,2,1, [0.05 0.05]); imshow(X_FISTA_student_TV,[0 0.6]); title('FISTA-Student-TV reconstruction'); colorbar;
 +subplot(1,2,2, [0.05 0.05]); imshow((phantom - X_FISTA_student_TV).^2,[0 0.1]);  title('residual'); colorbar;
  colormap(cmapnew); 
  figure(9); 
 -subplot_tight(1,2,1, [0.05 0.05]); plot(error_FISTA_student_TV);  title('RMSE plot'); colorbar;
 -subplot_tight(1,2,2, [0.05 0.05]); plot(obj_FISTA_student_TV);  title('Objective plot'); colorbar;
 +subplot(1,2,1, [0.05 0.05]); plot(error_FISTA_student_TV);  title('RMSE plot'); colorbar;
 +subplot(1,2,2, [0.05 0.05]); plot(obj_FISTA_student_TV);  title('Objective plot'); colorbar;
  colormap(cmapnew); 
  %%
  % print all RMSE's
 diff --git a/main_func/FISTA_REC.m b/main_func/FISTA_REC.m index e21ba60..688dcc3 100644 --- a/main_func/FISTA_REC.m +++ b/main_func/FISTA_REC.m @@ -72,7 +72,7 @@ if (isfield(params,'L_const'))      L_const = params.L_const;  else      % using Power method (PM) to establish L constant -    niter = 5; % number of iteration for PM +    niter = 6; % number of iteration for PM      x = rand(N,N,SlicesZ);      sqweight = sqrt(weights);      [sino_id, y] = astra_create_sino3d_cuda(x, proj_geom, vol_geom); @@ -145,11 +145,6 @@ if (isfield(params,'fidelity'))  else      fidelity = 'LS';  end -if (isfield(params,'precondition')) -    precondition = params.precondition; -else -    precondition = 0; -end  if (isfield(params,'show'))      show = params.show;  else @@ -166,6 +161,7 @@ else      slice = 1;  end  if (isfield(params,'initialize')) +   % a 'warm start' with SIRT method      % Create a data object for the reconstruction      rec_id = astra_mex_data3d('create', '-vol', vol_geom); @@ -191,7 +187,6 @@ else      X = zeros(N,N,SlicesZ, 'single'); % storage for the solution  end -  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%  Resid_error = zeros(iterFISTA,1); % error vector  objective = zeros(iterFISTA,1); % obhective vector @@ -218,12 +213,7 @@ if (lambdaR_L1 > 0)              add_ring(:,kkk,:) =  squeeze(sino(:,kkk,:)) - alpha_ring.*r_x;          end -        residual =  weights.*(sino_updt - add_ring); -         -        if (precondition == 1) -            residual = filtersinc(residual'); % filtering residual (Fourier preconditioning) -            residual = residual'; -        end         +        residual =  weights.*(sino_updt - add_ring);           vec = sum(residual,2);          if (SlicesZ > 1) @@ -295,13 +285,8 @@ else              %gr = (2)*res_vec./(s*2 + conj(res_vec).*res_vec);              [ff, gr] = studentst(res_vec,1);              residual = reshape(gr, Detectors, anglesNumb, SlicesZ); -        end -         -        if (precondition == 1) -            residual = filtersinc(residual'); % filtering residual (Fourier preconditioning) -            residual = residual'; -        end -         +        end         +                 [id, x_temp] = astra_create_backprojection3d_cuda(residual, proj_geom, vol_geom);          X = X_t - (1/L_const).*x_temp;          astra_mex_data3d('delete', sino_id); @@ -314,7 +299,7 @@ else              else                  objective(i) = 0.5.*norm(residual(:))^2 + f_val;              end -            %  X = SplitBregman_TV(single(X), lambdaTV, iterTV, tol);  % TV-Split Bregman regularization on CPU (memory limited) +           %X = SplitBregman_TV(single(X), lambdaTV, iterTV, tol);  % TV-Split Bregman regularization on CPU (memory limited)          elseif ((lambdaHO > 0) && (lambdaTV == 0))              % Higher Order regularization              X = LLT_model(single(X), lambdaHO, tauHO, iterHO, tol, 0);   % LLT higher order model @@ -338,10 +323,8 @@ else              fprintf('%s %i %s %s %.4f  %s %s %.4f \n', 'Iteration Number:', i, '|', 'Error RMSE:', Resid_error(i), '|', 'Objective:', objective(i));          else              fprintf('%s %i  %s %s %.4f \n', 'Iteration Number:', i, '|', 'Objective:', objective(i)); -        end -         -    end -     +        end         +    end      end  output.Resid_error = Resid_error;  output.objective = objective; diff --git a/supp/add_wedges.m b/supp/add_wedges.m deleted file mode 100644 index 5bc215c..0000000 --- a/supp/add_wedges.m +++ /dev/null @@ -1,35 +0,0 @@ -% create a wedge mask to simulate the missing wedge - -[rows, columns] = size(sino_zing_rings); -grayImage = ones(rows, columns, 'uint8'); -xCoords = [0 360 0]; -yCoords = [35 7 7]; -mask = poly2mask(xCoords, yCoords, rows, columns); -grayImage(mask) = 0;  - -xCoords = [727 360 727]; -yCoords = [35 7 7]; -mask = poly2mask(xCoords, yCoords, rows, columns); -grayImage(mask) = 0;  - -xCoords = [0 360 0]; -yCoords = [145 173 173]; -mask = poly2mask(xCoords, yCoords, rows, columns); -grayImage(mask) = 0;  - -xCoords = [727 360 727]; -yCoords = [145 173 173]; -mask = poly2mask(xCoords, yCoords, rows, columns); -grayImage(mask) = 0;  - -grayImage(1:7,:) = 0; -grayImage(173:end,:) = 0; - -%figure; imshow(grayImage, [0 1]); -MW_sino_artifacts = sino_zing_rings.*double(grayImage); -% !!! -% note that we do not re-calculate Dweights for MW_sino_artifacts -% if one does: Dweights = Dweights.*double(grayImage); -% then the MW artifacts will be reduced substantially,  -% through weighting. However we would like to explore  -% the effect of the penalty instead.
\ No newline at end of file diff --git a/supp/filtersinc.m b/supp/filtersinc.m deleted file mode 100644 index 6c29c98..0000000 --- a/supp/filtersinc.m +++ /dev/null @@ -1,28 +0,0 @@ -function g = filtersinc(PR) - - -% filtersinc.m -% -% Written by Waqas Akram -% -% "a":	This parameter varies the filter magnitude response. -%	When "a" is very small (a<<1), the response approximates |w| -%	As "a" is increased, the filter response starts to  -%	roll off at high frequencies. -a = 1; - -[Length, Count] = size(PR); -w = [-pi:(2*pi)/Length:pi-(2*pi)/Length]; - -rn1 = abs(2/a*sin(a.*w./2)); -rn2 = sin(a.*w./2); -rd = (a*w)./2; -r = rn1*(rn2/rd)^2; - -f = fftshift(r); -for i = 1:Count -        IMG = fft(PR(:,i)); -        fimg = IMG.*f'; -        g(:,i) = ifft(fimg); -end -g = real(g);
\ No newline at end of file diff --git a/supp/ssim_index.m b/supp/ssim_index.m deleted file mode 100644 index 4fa7a79..0000000 --- a/supp/ssim_index.m +++ /dev/null @@ -1,181 +0,0 @@ -function [mssim, ssim_map] = ssim_index(img1, img2, K, window, L) - -%======================================================================== -%SSIM Index, Version 1.0 -%Copyright(c) 2003 Zhou Wang -%All Rights Reserved. -% -%This is an implementation of the algorithm for calculating the -%Structural SIMilarity (SSIM) index between two images. Please refer -%to the following paper: -% -%Z. Wang, A. C. Bovik, H. R. Sheikh, and E. P. Simoncelli, "Image -%quality assessment: From error visibility to structural similarity" -%IEEE Transactios on Image Processing, vol. 13, no. 4, pp.600-612, -%Apr. 2004. -% -%Kindly report any suggestions or corrections to zhouwang@ieee.org -% -%---------------------------------------------------------------------- -% -%Input : (1) img1: the first image being compared -%        (2) img2: the second image being compared -%        (3) K: constants in the SSIM index formula (see the above -%            reference). defualt value: K = [0.01 0.03] -%        (4) window: local window for statistics (see the above -%            reference). default widnow is Gaussian given by -%            window = fspecial('gaussian', 11, 1.5); -%        (5) L: dynamic range of the images. default: L = 255 -% -%Output: (1) mssim: the mean SSIM index value between 2 images. -%            If one of the images being compared is regarded as  -%            perfect quality, then mssim can be considered as the -%            quality measure of the other image. -%            If img1 = img2, then mssim = 1. -%        (2) ssim_map: the SSIM index map of the test image. The map -%            has a smaller size than the input images. The actual size: -%            size(img1) - size(window) + 1. -% -%Default Usage: -%   Given 2 test images img1 and img2, whose dynamic range is 0-255 -% -%   [mssim ssim_map] = ssim_index(img1, img2); -% -%Advanced Usage: -%   User defined parameters. For example -% -%   K = [0.05 0.05]; -%   window = ones(8); -%   L = 100; -%   [mssim ssim_map] = ssim_index(img1, img2, K, window, L); -% -%See the results: -% -%   mssim                        %Gives the mssim value -%   imshow(max(0, ssim_map).^4)  %Shows the SSIM index map -% -%======================================================================== - - -if (nargin < 2 | nargin > 5) -   ssim_index = -Inf; -   ssim_map = -Inf; -   return; -end - -if (size(img1) ~= size(img2)) -   ssim_index = -Inf; -   ssim_map = -Inf; -   return; -end - -[M N] = size(img1); - -if (nargin == 2) -   if ((M < 11) | (N < 11))   % ͼССû塣 -           ssim_index = -Inf; -           ssim_map = -Inf; -      return -   end -   window = fspecial('gaussian', 11, 1.5);        % һƫ1.511*11ĸ˹ͨ˲ -   K(1) = 0.01;                                                                      % default settings -   K(2) = 0.03;                                                                      % -   L = 255;                                  % -end - -if (nargin == 3) -   if ((M < 11) | (N < 11)) -           ssim_index = -Inf; -           ssim_map = -Inf; -      return -   end -   window = fspecial('gaussian', 11, 1.5); -   L = 255; -   if (length(K) == 2) -      if (K(1) < 0 | K(2) < 0) -                   ssim_index = -Inf; -                   ssim_map = -Inf; -                   return; -      end -   else -           ssim_index = -Inf; -           ssim_map = -Inf; -           return; -   end -end - -if (nargin == 4) -   [H W] = size(window); -   if ((H*W) < 4 | (H > M) | (W > N)) -           ssim_index = -Inf; -           ssim_map = -Inf; -      return -   end -   L = 255; -   if (length(K) == 2) -      if (K(1) < 0 | K(2) < 0) -                   ssim_index = -Inf; -                   ssim_map = -Inf; -                   return; -      end -   else -           ssim_index = -Inf; -           ssim_map = -Inf; -           return; -   end -end - -if (nargin == 5) -   [H W] = size(window); -   if ((H*W) < 4 | (H > M) | (W > N)) -           ssim_index = -Inf; -           ssim_map = -Inf; -      return -   end -   if (length(K) == 2) -      if (K(1) < 0 | K(2) < 0) -                   ssim_index = -Inf; -                   ssim_map = -Inf; -                   return; -      end -   else -           ssim_index = -Inf; -           ssim_map = -Inf; -           return; -   end -end -%% -C1 = (K(1)*L)^2;    % C1Lxyá -C2 = (K(2)*L)^2;    % C2ԱȶCxyá -window = window/sum(sum(window)); %˲һ -img1 = double(img1);  -img2 = double(img2); - -mu1   = filter2(window, img1, 'valid');  % ͼ˲ӼȨ -mu2   = filter2(window, img2, 'valid');  % ͼ˲ӼȨ - -mu1_sq = mu1.*mu1;     % Uxƽֵ -mu2_sq = mu2.*mu2;     % Uyƽֵ -mu1_mu2 = mu1.*mu2;    % Ux*Uyֵ - -sigma1_sq = filter2(window, img1.*img1, 'valid') - mu1_sq;  % sigmax  -sigma2_sq = filter2(window, img2.*img2, 'valid') - mu2_sq;  % sigmay  -sigma12 = filter2(window, img1.*img2, 'valid') - mu1_mu2;   % sigmaxy - -if (C1 > 0 & C2 > 0) -   ssim_map = ((2*mu1_mu2 + C1).*(2*sigma12 + C2))./((mu1_sq + mu2_sq + C1).*(sigma1_sq + sigma2_sq + C2)); -else -   numerator1 = 2*mu1_mu2 + C1; -   numerator2 = 2*sigma12 + C2; -   denominator1 = mu1_sq + mu2_sq + C1; -   denominator2 = sigma1_sq + sigma2_sq + C2; -   ssim_map = ones(size(mu1)); -   index = (denominator1.*denominator2 > 0); -   ssim_map(index) = (numerator1(index).*numerator2(index))./(denominator1(index).*denominator2(index)); -   index = (denominator1 ~= 0) & (denominator2 == 0); -   ssim_map(index) = numerator1(index)./denominator1(index); -end - -mssim = mean2(ssim_map); - -return
\ No newline at end of file diff --git a/supp/subplot_tight.m b/supp/subplot_tight.m deleted file mode 100644 index 0b0cbd5..0000000 --- a/supp/subplot_tight.m +++ /dev/null @@ -1 +0,0 @@ -function vargout=subplot_tight(m, n, p, margins, varargin)
%% subplot_tight
% A subplot function substitude with margins user tunabble parameter.
%
%% Syntax
%  h=subplot_tight(m, n, p);
%  h=subplot_tight(m, n, p, margins);
%  h=subplot_tight(m, n, p, margins, subplotArgs...);
%
%% Description
% Our goal is to grant the user the ability to define the margins between neighbouring
%  subplots. Unfotrtunately Matlab subplot function lacks this functionality, and the
%  margins between subplots can reach 40% of figure area, which is pretty lavish. While at
%  the begining the function was implememnted as wrapper function for Matlab function
%  subplot, it was modified due to axes del;etion resulting from what Matlab subplot
%  detected as overlapping. Therefore, the current implmenetation makes no use of Matlab
%  subplot function, using axes instead. This can be problematic, as axis and subplot
%  parameters are quie different. Set isWrapper to "True" to return to wrapper mode, which
%  fully supports subplot format.
%
%% Input arguments (defaults exist):
%   margins- two elements vector [vertical,horizontal] defining the margins between
%        neighbouring axes. Default value is 0.04
%
%% Output arguments
%   same as subplot- none, or axes handle according to function call.
%
%% Issues & Comments
%  - Note that if additional elements are used in order to be passed to subplot, margins
%     parameter must be defined. For default margins value use empty element- [].
%  - 
%
%% Example
% close all;
% img=imread('peppers.png');
% figSubplotH=figure('Name', 'subplot');
% figSubplotTightH=figure('Name', 'subplot_tight');
% nElems=17;
% subplotRows=ceil(sqrt(nElems)-1);
% subplotRows=max(1, subplotRows);
% subplotCols=ceil(nElems/subplotRows);
% for iElem=1:nElems
%    figure(figSubplotH);
%    subplot(subplotRows, subplotCols, iElem);
%    imshow(img);
%    figure(figSubplotTightH);
%    subplot_tight(subplotRows, subplotCols, iElem, [0.0001]);
%    imshow(img);
% end
%
%% See also
%  - subplot
%
%% Revision history
% First version: Nikolay S. 2011-03-29.
% Last update:   Nikolay S. 2012-05-24.
%
% *List of Changes:*
% 2012-05-24
%  Non wrapping mode (based on axes command) added, to deal with an issue of disappearing
%     subplots occuring with massive axes.
%% Default params
isWrapper=false;
if (nargin<4) || isempty(margins)
    margins=[0.04,0.04]; % default margins value- 4% of figure
end
if length(margins)==1
    margins(2)=margins;
end
%note n and m are switched as Matlab indexing is column-wise, while subplot indexing is row-wise :(
[subplot_col,subplot_row]=ind2sub([n,m],p);  
height=(1-(m+1)*margins(1))/m; % single subplot height
width=(1-(n+1)*margins(2))/n;  % single subplot width
% note subplot suppors vector p inputs- so a merged subplot of higher dimentions will be created
subplot_cols=1+max(subplot_col)-min(subplot_col); % number of column elements in merged subplot 
subplot_rows=1+max(subplot_row)-min(subplot_row); % number of row elements in merged subplot   
merged_height=subplot_rows*( height+margins(1) )- margins(1);   % merged subplot height
merged_width= subplot_cols*( width +margins(2) )- margins(2);   % merged subplot width
merged_bottom=(m-max(subplot_row))*(height+margins(1)) +margins(1); % merged subplot bottom position
merged_left=min(subplot_col)*(width+margins(2))-width;              % merged subplot left position
pos=[merged_left, merged_bottom, merged_width, merged_height];
if isWrapper
   h=subplot(m, n, p, varargin{:}, 'Units', 'Normalized', 'Position', pos);
else
   h=axes('Position', pos, varargin{:});
end
if nargout==1
   vargout=h;
end
\ No newline at end of file | 
