Rotating values within a meshgrid

I have X,Y,Z values from a bathymetry survey. I am able to create a meshgrid and grid the data just fine. The issue that I am experiencing is that since my survey area is not perfectly square (it is more of a diagonal rectangle, see below), there are an etreme amount of NaNs within my meshgrid. I have tried changing the NaNs to a number (like 0), as well as interpolating in the griddata function, but this is misrepresenting what is in my data. Ultimatly, I am trying to preform a SVD for the matrix, but I cannot have NaNs to run this function. The simplest solution I can think of is to 'rotate' the data within my meshgrid. Can anyone give advice?

Thank you,

Thank you,

Christina

Answer 1

[darova]

So maybe rotate your data and apply griddata() again

a = 45;
R = [cosd(a) sind(a); -sind(a) cosd(a)];
V = R*[x(:) y(:)]';
xnew = V(1,:);
ynew = V(2,:);
rangex = linspace(min(xnew),max(xnew),30);
rangey = linspace(min(ynew),max(ynew),30);
[X1,Y1] = meshgrid(rangex,rangey);
Z1 = griddata(xnew,ynew,z,X1,Y1);