maltab课程实验

function [h, display_array] = displayData(X, example_width) %DISPLAYDATA Display 2D data in a nice grid % [h, display_array] = DISPLAYDATA(X, example_width) displays 2D data % stored in X in a nice grid. It returns the figure handle h and the % displayed array if requested. % Set example_width automatically if not passed in if ~exist('example_width', 'var') || isempty(example_width) example_width = round(sqrt(size(X, 2))); end % Gray Image colormap(gray); % Compute rows, cols [m n] = size(X); example_height = (n / example_width); % Compute number of items to display display_rows = floor(sqrt(m)); display_cols = ceil(m / display_rows); % Between images padding pad = 1; % Setup blank display display_array = - ones(pad + display_rows * (example_height + pad), ... pad + display_cols * (example_width + pad)); % Copy each example into a patch on the display array curr_ex = 1; for j = 1:display_rows for i = 1:display_cols if curr_ex > m, break; end % Copy the patch % Get the max value of the patch max_val = max(abs(X(curr_ex, :))); display_array(pad + (j - 1) * (example_height + pad) + (1:example_height), ... pad + (i - 1) * (example_width + pad) + (1:example_width)) = ... reshape(X(curr_ex, :), example_height, example_width) / max_val; curr_ex = curr_ex + 1; end if curr_ex > m, break; end end % Display Image h = imagesc(display_array, [-1 1]); % Do not show axis axis image off drawnow; end