histograms for ND data 1.0

histnd Histogram count of ND data with ND bins histmat = histnd(x, y, ..., xedges, yedges, ...) Extract ND histogram data containing the number of events of [x, y, ...] tuples that fall in each bin of the ND-grid defined by xedges, yedges, .... The edges are passed to histc internally and should therefore conform to histc's input restrictions: the edge-vectors should be monotonically non-decreasing. [histmat, nOOF, OOFidx] = histnd(x, y, ..., xedges, yedges, ...) If any values are outside of the range of the edges, they are not counted. The number of those cases and their linear index in the input data is however returned in the second and third output arguments. EXAMPLES events = 1000000; x1 = sqrt(0.05)*randn(events,1)-0.5; x2 = sqrt(0.05)*randn(events,1)+0.5; y1 = sqrt(0.05)*randn(events,1)+0.5; y2 = sqrt(0.05)*randn(events,1)-0.5; x= [x1;x2]; y = [y1;y2]; For linearly spaced edges: xedges = linspace(-1,1,64); yedges = linspace(-1,1,64); histmat = histnd(x, y, xedges, yedges); figure; pcolor(xedges,yedges,histmat'); colorbar ; axis square tight ; For nonlinearly spaced edges: xedges_ = logspace(0,log10(3),64)-2; yedges_ = linspace(-1,1,64); histmat_ = histnd(x, y, xedges_, yedges_); figure; pcolor(xedges_,yedges_,histmat_'); colorbar ; axis square tight ; 3D data x = 3.*randn(640000,1); y = 1.*randn(640000,1); z = 1.*randn(640000,1); histmat = histnd(x,y,z,linspace(min(x),max(x),20),linspace(min(y),max(y),20),linspace(min(z),max(z),20)); % make 3D hist, color of points indicates count [xp,yp,zp] = meshgrid(linspace(min(x),max(x),20),linspace(min(y),max(y),20),linspace(min(z),max(z),20)); % cut away histogram positions where count is 0 qzero = histmat==0; histmat(qzero) = []; xp(qzero) = []; yp(qzero) = []; zp(qzero) = []; % draw points figure;%('Renderer','OpenGL') % might need the openGL renderer to handle so many points ax = scatter3(xp(:),yp(:),zp(:),'.'); % color them according to count cdata = histmat(:)./max(histmat); set(ax,'CData',cdata); xlabel('X'), ylabel('Y'), zlabel('Z')

Requirements:	No special requirements
Platforms:	Matlab
Keyword:	Color,  Histmat,  Logspace Log,  Nonlinearly,  Points,  Randn,  Tight,  Xedges,  Yedges
Users rating:	0/10