Converting gridded elevation data and x, y coords into row output

We are dealing with UTM coords here, and we have: Northings, Eastings, and gridded Elevation-values.

dimensions--

x is 1x30

y is 1x41

z is 41x30

Currently this meshes well into a surface.

How can I export this data into rows of:

x1, y1, z1;

x2,y2,z2;

....

xend,yend,zend

?

[Wthee]

Thanks so much. Matlab is really akin to an onion with all too many layers!

[Wthee]

Here's a followup...

Do you know if there is a way to have contour outputs at certain z values? E.g., somehow setting z = 0 and finding all x,y coords that intersect that plane? I'm guessing there would have to be interpolation involved?

[Walter Roberson]

You can pass a level list to contour() . If you are only passing one value, then the trick is to pass it twice:

contour(x, y, z, 2)      %asks for two contours
contour(x, y, z, [2 2])  %asks for a contour at z = 2

Interpreting the contour matrix that you can return from contour() is a nuisance. There are some File Exchange submissions that make it easier.

Answer 1

[David Hill]

Not sure I understand your question.

[X,Y]=meshgrid(x,y);%assume this is what you want
data=[X(:),Y(:),z(:)];

[Wthee]

Fast!

that creates a big matrix: 1230x3

Is there a way to remove NaN values from the output to decrease the number of rows to having data only?

[David Hill]

Do you have entire rows that are nan that you want to delete? Or any row the has a nan value within the row?

[idx,~]=find(isnan(data));
data(idx,:)=[];

[Walter Roberson]

With new enough MATLAB you could

rmmissing(data)

if you wanted to remove any row that has one or more nan.

[Wthee]

https://4.bp.blogspot.com/-fB9dOyAWSts/T5AkQO07J7I/AAAAAAAAAiA/sBFSsqPu1C4/s1600/THUMBS+UPP.jpg

[Wthee]

Good Work -- David and Walter... much appreciated.