Extracting a timeseries of x,y values from a series of .asc files

Question

Matthew Cooper 2013-4-3

0
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https://ww2.mathworks.cn/matlabcentral/answers/69596-extracting-a-timeseries-of-x-y-values-from-a-series-of-asc-files

Hi,

I have what I think is a very simple Matlab problem. I need to extract the value of an x,y cell in a series of .asc grid files, and write these values to a matrix.

A more detailed description. I have a grid of values that represent a spatial domain, and each value in the grid represents a meteorological parameter like temperature. Each .asc grid file represents a day. So each file is a grid of daily temperature. I need to write a matlab script that will go through each file (each day), go to a specified row,column in the grid, pull out the value, and then create a time series of the values.

My files are saved in the format: Tair.YYYY.MM.DD.asc. They have a header with 6 lines at top. Tair is air temperature, swe_depth is snow depth. hogg is the name of the met station. (550,21) is the row/column I am interested in.

Here is what I think should work:

a=dir('Tair*.asc'); s=dir('swe_depth*.asc');

for i=1:length(a) Air = textread(a(i).name,'',-1,'headerlines',6); swe = textread(s(i).name,'',-1,'headerlines',6);

    hogg(i,1) = Air(550,21);
    hogg(i,2) = swe(550,21);

end

This works, but I end up with a 31x31 matrix instead of a 31x2 matrix which is what I want.

Also, I know that this should be done using arcgridread or maybe textscan, if anyone wants to suggest how to do it better using one of those two functions I am all ears!