Loop Code Through Each Row of Excel Spreadsheet and Save Result Matrix
1 Ansicht (letzte 30 Tage)
Ältere Kommentare anzeigen
CMatlabWold
am 27 Feb. 2023
Bearbeitet: M.B
am 8 Aug. 2023
I haven't been on MATLAB for a while. I suppose I am very rusty. But I have a spreadsheet, and there are two columns of interest: one is labeled x_coord and the other is labeled y_coord. For each row of both columns, I am converting the x and y coordinate values to longitude and latitude degree values. Then, I am writing the results in a matrix. However, it is just not working. I am looking to have a pair of latitude and longitude values for each row, based on the x and y cooredinates. I'd greatly appreciate any help.
N=[];
for K = 1:172
data = readtable('zipcode_information2.csv', 'PreserveVariableNames',true)
X = data(:,ismember(data.Properties.VariableNames, {'x_coord'}))
Y = data(:,ismember(data.Properties.VariableNames, {'y_coord'}))
info = shapeinfo('ZIP_CODE_040114.shp');
proj = info.CoordinateReferenceSystem;
[lat,lon] = projinv(proj,X{i,1},Y{i,1});
outdata = [lat,lon]
N = [N; outdata]
end
writematrix(N, 'LongLat.csv',"WriteMode","append")
0 Kommentare
Akzeptierte Antwort
Cris LaPierre
am 27 Feb. 2023
You don't need a loop. Perform the calculation on the entire column at once.
data = readtable('zipcode_information2.csv', 'PreserveVariableNames',true)
info = shapeinfo('ZIP_CODE_040114.shp');
proj = info.CoordinateReferenceSystem;
[lat,lon] = projinv(proj,data.x_coord,data.y_coord);
N = [lat,lon]
writematrix(N, 'LongLat.csv',"WriteMode","append")
Weitere Antworten (1)
M.B
am 27 Feb. 2023
Bearbeitet: M.B
am 8 Aug. 2023
The issue is with your indexing. You declare K as the index and use i inside the loop.
I agree with Cris, you don't need a loop. The function "projinv" takes vectors as inputs. If you insist on using a loop, you can try the following:
% place all fixed parameters outside the loop
N=nan(172, 2);
data = readtable('zipcode_information2.csv', 'PreserveVariableNames',true);
X = data(:,ismember(data.Properties.VariableNames, {'x_coord'}));
Y = data(:,ismember(data.Properties.VariableNames, {'y_coord'}));
info = shapeinfo('ZIP_CODE_040114.shp');
proj = info.CoordinateReferenceSystem;
for K = 1:172
[lat,lon] = projinv(proj,X(K),Y(K));
outdata = [lat,lon];
N(K, :) = outdata;
end
writematrix(N, 'LongLat.csv',"WriteMode","append");
Siehe auch
Kategorien
Mehr zu Spreadsheets finden Sie in Help Center und File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!