How to update main grid with a seperately created subgrid values

Hello dear all,

Currently, having a difficulty to design an algorithm to update a grid's Z values with another subgrid values.

The main grid is 93x315 X,Y and Z(with NaN values). X,Y horizontal coordinates and Z is elevation.

Have another (xq,yq and zq) grid which is 24x24, I call it subgrid. This subgrid has X,Y values which cover smaller area inside of the main grid but Z values are different as it was interpolated. How can I substitute main grid's Z values with subgrid's interpolated Z values by finding correct location using their X and Y values.

As this issue exceeds my abilities, I would be appreciated for any suggestions, Thank you, Alper.

Answer 1

[darova]

Here is an example

ind1 = X < min(x(:)) & X < max(x(:));   % indices inbetween smallest and largest 'x'
ind2 = Y < min(y(:)) & Y < max(y(:));   % indices inbetween smallest and largest 'y'
ind = ind1 & ind2;                      % here is a region inside big matrix

The question: is the region will have size 24x24?

[Mustafa Alper Cetintas]

thank you a lot for your suggestion, really appreciated. I tried your script and I was able to find corresponding indexes in the main grid with this. the only thing remaining was assigning Z values at found indexes and I could somehow done that.

only made a change as below;

ind1 = X > min(x(:)) & X < max(x(:)); % indices inbetween smallest and largest 'x'

ind2 = Y > min(y(:)) & Y < max(y(:)); % indices inbetween smallest and largest 'y'

to answer your question, region size will change everytime but will stay inside of the main grid. and each time this one has been able to find indexes.

[darova]

happy to help