added prominence

@GRIDobj/prominence.m

@@ -0,0 +1,79 @@
+function [x,y,p] = prominence(DEM,tol)
+
+%PROMINENCE Calculate the prominence of mountain peaks
+%
+% Syntax
+%
+% [x,y,p] = prominence(DEM,tol)
+%
+% Description
+%
+% This function calculates the prominence of peaks in a DEM. The
+% prominence is the minimal amount one would need to descend from a
+% peak before being able to ascend to a higher peak.
+%
+% The function uses image reconstruct (see function imreconstruct) to
+% calculate the prominence. It may take a while to run for large DEMs.
+% The algorithm iteratively finds the next higher prominence and stops
+% if the prominence is less than the tolerance, the second input
+% parameter to the function.
+%
+% The function opens a waitbar which let's you quit the operation. The
+% list of coordinates and prominence values derived until then, are
+% returned as output arguments.
+%
+% Input arguments
+%
+% DEM Digital elevation model (GRIDobj)
+% tol tolerance in [m] with the minimum prominence.
+%
+% Output arguments
+%
+% x,y coordinate values of peaks
+% p prominence (the first element in the vector contains the
+% highest peak for which prominence (given above definition)
+% cannot be calulated.
+%
+% See also: GRIDobj
+%
+% Author: Wolfgang Schwanghart (w.schwanghart[at]geo.uni-potsdam.de)
+% Date: 28. June, 2021
+
+if any(isnan(DEM))
+ DEM.Z(isnan(DEM.Z)) = 0;
+end
+
+P = GRIDobj(DEM)+min(DEM);
+P2 = P;
+C = P;
+
+counter = 1;
+p = inf;
+
+f = waitbar(0,'1','Name','Calculating prominence...',...
+ 'CreateCancelBtn','setappdata(gcbf,''canceling'',1)');
+
+setappdata(f,'canceling',0);
+
+
+while p(end) > tol 
+
+ [p(counter),ix(counter)] = max(DEM-P);
+
+ waitbar(min(max(tol/p(end),0),1),f,sprintf('%5.2f',p(end)))
+
+ P.Z(ix) = DEM.Z(ix);
+ P.Z = imreconstruct(P.Z,DEM.Z);
+ counter = counter + 1;
+
+ % Check for clicked Cancel button
+ if getappdata(f,'canceling')
+ break
+ end
+
+end
+
+delete(f);
+[x,y] = ind2coord(DEM,ix);
+p = p(:);
+

colormaps/ttscm.m

@@ -57,10 +57,12 @@
 %
 % DEM = GRIDobj('srtm_bigtujunga30m_utm11.tif');
 % cmaps = ttscm;
+% tiledlayout('flow','TileSpacing','none');
 % for r = 1:numel(cmaps); 
-% subplot(6,4,r); 
+% nexttile 
 % imageschs(DEM,[],'colormap', ttscm(cmaps{r}),...
-% 'colorbar',false,'ticklabels','none');
+% 'colorbar',false,'ticklabels','none',...
+% 'useperm',true);
 % title(cmaps{r});
 % end
 %
@@ -100,7 +102,7 @@
  'InitialMagnification','fit')
  return
 elseif nargin == 0 && nargout == 1
- cmap = allowedcmaps;
+ cmap = sort(allowedcmaps);
  return
 end
 

readme.md

@@ -117,7 +117,7 @@ resource for code and examples is the [TopoToolbox blog](http:https://topotoolbox.word
 - new class: DIVIDEobj [Paper 1 DOI: 10.5194/esurf-8-245-2020](https://doi.org/10.5194/esurf-8-245-2020)
  [Paper 2 DOI: 10.5194/esurf-8-261-2020](https://doi.org/10.5194/esurf-8-261-2020)
 - new class: PPS [DOI: 10.1002/esp.5127](http:https://dx.doi.org/10.1002/esp.5127)
-- modification: update to ttscm to include cyclic colormaps; 
+- modification: update to ttscm to Scientific Colormaps 7.0
  see [Fabio Crameri's website](http:https://www.fabiocrameri.ch/colourmaps.php)
 - new function: GRIDobj/diffusion
 - new function: GRIDobj/histogram