How to display minimum vaue of a Surface z-axis.

I have drew a trisurf with 100 values in each x,y and z variable, and I want to display the least 10 data values of z on the surface over the location of the points .

Answer 1

[Image Analyst]

sortedValues = sort(z(:), 'ascend');
fprintf('%f\n', sortedValues(1:10));

Use text() if you want to display some message above the data point.

[Image Analyst]

I noticed your attempt at using text below:

text(Xmin+xgap, Ymin+ygap, Zmin+zgap);

like I suggested, but where is the message you want to display? You didn't supply it. Try creating a message like I said:

message = sprintf('Zmin=%.2f', Zmin);  % Create string for the Zmin point.
text(Xmin+xgap, Ymin+ygap, Zmin+zgap, message);

Answer 2

[Matt Kindig]

You can do this using text() function. Something like this:

%Xval, Yval, and Zval are your MxN matrices used to make the surface.
Zmin = sort(Zval(:), 'descend');  %sort z decreasing
Zmin = Zmin(1:10);   %10 smallest z values
pos = ismember(Zval, Zmin);  %location of Z values
Xmin = reshape(Xval(pos),[],1);  
Ymin = reshape(Yval(pos),[],1);
xgap = 1; ygap = 1; zgap = 1;  %adjust to get desired spacing of label from point.
text( Xmin+xgap, Ymin+ygap, Zmin+zgap);

[Matt Kindig]

Or maybe I misunderstood your question. Are you asking how to plot these points? In that case, just use plot3():

hold on; 
plot3( Xmin, Ymin, Zmin, 'o');

[Afz]

I just want the numeric values used to plot the surface be printed over those z points. Data labels of z over each point. I used your code it gives following error.

??? Error using ==> text String argument expected after 2 or 3 numeric arguments

Error in ==> FILENAME at 23 text(Xmin+xgap, Ymin+ygap, Zmin+zgap);

I am using this code

if true
 holdState = ishold;
Xval = xlsread('a.xlsx',1,'A1:CV1');
%Defining y
Yval = xlsread('a.xlsx',1,'A2:CV2');
%Defining z
Zval = xlsread('a.xlsx',1,'A3:CV3');
tri = delaunay(Xval,Yval);
h1 = trisurf(tri, Xval, Yval, Zval);
set(h1, 'FaceColor', 'g')
xlabel('Granular Rutting B4');
ylabel('Fine Rutting B5');
zlabel('RSS');
hold on;
iamlegend = legend('1'); 
Zmin = sort(Zval(:), 'descend');  %sort z decreasing % code
Zmin = Zmin(1:10);   %10 smallest z values
pos = ismember(Zval, Zmin);  %location of Z values
Xmin = reshape(Xval(pos),[],1);  
Ymin = reshape(Yval(pos),[],1);
xgap = 1; ygap = 1; zgap = 1;  %adjust to get desired spacing of label from point.
text(Xmin+xgap, Ymin+ygap, Zmin+zgap);
if ~holdState,
  hold off; 
end