# Matlab不规则形状的冲浪样图Matlab irregular shape surf-like plot

## 1 个回复1

### ===============>>#1 票数：1 已采纳

``````function matrix_lower_tri_to_surf(A)
%Displays lower triangle portion of matrix as an equilateral triangle
%Martin Stålberg, Uppsala University, 2013-07-12
%mast4461 at gmail

siz = size(A);
N = siz(1);
if ~(ndims(A)==2) || ~(N == siz(2))
error('Matrix must be square');
end

zeds = @(N) zeros(N*(N+1)/2,1); %for initializing coordinate vectors
x = zeds(N); %x coordinates
y = zeds(N); %y coordinates
z = zeds(N); %z coordinates, will remain zero
r = zeds(N); %row indices
c = zeds(N); %column indices

l = 0; %base index
xt = 1:N; %temporary x coordinates
yt = 1; %temporary y coordinates

for k = N:-1:1
ind = (1:k)+l; %coordinate indices
l = l+k; %update base index

x(ind) = xt; %save temporary x coordinates

%next temporary x coordinates are the k-1 middle pairwise averages
%calculated by linear interpolation through convolution
xt = conv(xt,[.5,.5]);
xt = xt(2:end-1);

y(ind) = yt; %save temporary y coordinates
yt = yt+1; %update temporary y coordinates

r(ind) = N-k+1; %save row indices
c(ind) = 1:k; % save column indices
end

v = A(sub2ind(size(A),r,c)); %extract values from matrix A
tri = delaunay(x,y); %create triangular mesh

h = trisurf(tri,x,y,z,v,'edgecolor','none','facecolor','interp'); %plot surface
axis vis3d; view(2); %adjust axes projection and proportions
daspect([sqrt(3)*.5,1,1]); %adjust aspect ratio to display equilateral triangle

end %end of function
``````

2回复

1回复

1回复

1回复

1回复

2回复

1回复

1回复

1回复

3回复