MATLAB: I keep on getting this error when I try to turn the given data into a graph

3d plotscontourcsvgraphsurface

I am really new at MATLAB but i have to turn my 3 csv files into a graph. This is my code that I cuurently have

A=importdata('mariana_depth.csv');
lon=importdata('mariana_longitude.csv');
lat=importdata('mariana_latitude.csv');
surfc(A,lon,lat);
colorbar;

And this is the error i get

Error using surfc (line 46)
The surface Z must contain more than one
row or column.
Error in Project_2_1 (line 4)
surfc(A,lon,lat);

How would I code this correctly?

Best Answer

A=importdata('mariana_depth.csv');
lon=importdata('mariana_longitude.csv');
lat=importdata('mariana_latitude.csv');
[lat_grid,lon_grid] = meshgrid(lat,lon);
figure
surfc(lat_grid,lon_grid,A);
colorbar;

Note that because of the large amount of data you have, the figure quality is not that great. (If the figure window is not very large, it appears as just a blackish blob.) The contour plot renders pretty well, though.

You could consider just using a sample of the data. For example

figure
surfc(lat_grid(1:5:end,1:5:end),lon_grid(1:5:end,1:5:end),A(1:5:end,1:5:end));
colorbar;

looks much better:

Or you could plot in sections.

Related Solutions

MATLAB: Visualizing Geoid Height with given longitude, latitude and geoid heights

First, create a 2D map of the heights were the rows are latitude and the columns are longitude.

You could use the matlab unique() on the list of latitudes and on the list of longitudes to create 1D arrays to define the row and column values. Then use the meshgrid command to make a 2D map of latitude and a 2D map of longitude. If the data are nicely ordered you can just use the reshape command to make the 1D array of heights into a 2D array. If it is not, then loop through lat and lon of the 2D array (each pixel) and search the Nx2 array accordingly doing a nearest neighbor interpolation into the 2D array of heights.

Most likely the data are nicely ordered so that reshape will work to create the 2D array. You might need to transpose the array. If each record first loops through a series of latitudes for one longitude, then increments longitude and loops through the same set of latitudes, then the height data. Below is some script code that creates fake topo data to illustrate:

nlong = 50;

nlat = 25;

[ICOL,IROW] = meshgrid(1:nlong,1:nlat);

longitude = zeros(nlat,nlong);

latitude = zeros(nlat,nlong);

height = zeros(nlat,nlong);

for ilong = 1:nlong

for ilat = 1:nlat

longitude(ilat,ilong) = 0.5*ilong - 70;

latitude(ilat,ilong) = 0.5*ilat + 40;

height(ilat,ilong) = 2i*pi*rand(1,1);

end

% making better fake data to illustrate

height = abs(ifft2(ifftshift((hypot(IROW,ICOL)+1e-5).^(-2.1).*exp(height))));

% shows ordering of longitude outer cycle and latitude inner cycle

% this is very likely how your data are organized

X = reshape(longitude,nlat*nlong,1);

Y = reshape(latitude,nlat*nlong,1);

Z = reshape(height,nlat*nlong,1);

for ipt = 1:nlat*nlong

fprintf(1,'%f %f %f\n',X(ipt),Y(ipt),Z(ipt));

end

% if this is how your data are arranged, then to create the 2D map:

latitude1D = unique(Y);

longitude1D = unique(X);

height2D = reshape(Z,nlat,nlong);

latitude2D = reshape(Z,nlat,nlong);

longitude2D = reshape(Z,nlat,nlong);

% if the reverse is true, that latitude is the outer cycle, then you need

% to transpose the result

% height2D = height2D';

%% referene matrix

% Reference matrix for mapping geoid heights to lat/lon on globe.

R1 = makerefmat('RasterSize',size(height2D), ...

'Latlim', [min(latitude(:)) max(latitude(:))], ...

'Lonlim', [min(longitude(:)) max(longitude(:))] );

%% visualization 1: DTED map with contour lines

figure();

hold on;

mapshow(zeros(size(height2D)),R1,'CData',height2D,'DisplayType','surface');

cW = mapshow(height2D,R1,'DisplayType','contour','linecolor','black', ...

'showtext','on');

demcmap(height2D);

axis equal

axis tight

%% visualization 2: with coastline

coast = load('coast');

% Create 2-D plot using |meshm|

h2D = figure;

set(h2D,'Position',[20 75 700 600],'Toolbar','figure');

gridDegInc = 0.5;

ast2DGeoidPlot(R1,height2D,coast,gridDegInc)

%% another visualization using the aerospace toolbox

figure

gcm = usamap([min(latitude1D) max(latitude1D)], [min(longitude1D) max(longitude1D)]);

hold on;

geoshow(gcm,height2D,R1,'DisplayType','texturemap');

demcmap(height2D);

daspectm('m',1);

geoshow(latitude2D,longitude2D,height2D,'DisplayType','contour', ...

'LineColor','black');

%% another visualization

figure

gcm = usamap([min(latitude1D) max(latitude1D)], [min(longitude1D) max(longitude1D)]);

hold on;

geoshow(gcm,height2D,R1,'Zdata',height2D, 'CData',height2D,'DisplayType','surface')

demcmap(height2D)

daspectm('m',1)

view(3)

MATLAB: How to make a color-map from lat long and data.

try this

data = readmatrix('data.xlsx');
lat = data(:,1);
lon = data(:,2);
val = data(:,3);
latV = linspace(min(lat), max(lat), 100);
lonV = linspace(min(lon), max(lon), 100);
[latG, lonG] = meshgrid(latV, lonV);
valG = griddata(lat, lon, val, latG, lonG);
contourf(latG, lonG, valG, 100, 'LineColor', 'none')
colormap(jet)
colorbar

Best Answer

Related Solutions

MATLAB: Visualizing Geoid Height with given longitude, latitude and geoid heights

MATLAB: How to make a color-map from lat long and data.

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