How to overlap several maps?

Hi all,

I wrote two codes (code 1 and code 2) below to produce the pictures attach within htis question. I would like to add on th figure showing the vessel density (vessel density.png file; code 1), the limit of the coastal area of the United Kingdom (and associated islands) and Ireland using M_map (also attached here: UK.jpg; code 2). does someone how can I write one code to have both on it? Also, if someone knows how to fill the land (inside the coastal limit) in white to make it look better that would be also great.

Regards

%% Code 1

% assign the path to your working directory:
cd ('E:\Data_emodnet_fisheries\Vessel_density\');

load Average.mat % Matrice representing the positon of boat in the sea

imshow(Average,Colormap=turbo);

limits = [0,3];
c = colorbar;
set(gca,'clim',limits([1,end]));
c.Label.String = 'Vessel density (h/m2/month)';

saveas(gcf,'Vessel_density.png')

%% Code 2
% assign the path to your working directory:
cd ('E:\publi\Waiting-room\Matt_paper_hydrogen\figure_Matt\new\gshhg-bin-2.3.7(1)\');

% add path to TelemacTolls functions (i.e. to read in telemac files into MATLAB):
addpath ('C:\Matlab_download\m_map1.4\m_map\');

workingFolder = tempdir;

latlim = [48 63];
lonlim = [-12 3];
S = gshhs('gshhs_h.b', latlim, lonlim);

levels = [S.Level];
L1 = S(levels == 1);

figure
plot ([L1.Lon],[L1.Lat], '-b');
xlim([-11 3]);
ylim([49 61]);

Answer 1

[Kevin Holly]

You could edit the colormap to make the land white.

figure
image
colorbar
colormap turbo

figure(2)
image
colorbar
cmap = turbo;
cmap(1:4,:)=ones(4,3);
colormap(cmap)

In your case, you can do the following:

cmap = turbo;
cmap(1:4,:)=ones(4,3);
imshow(Average,Colormap=cmap);

You may need to adjust the range in which the color is white ([1 1 1]).

As for overlaying the plot on the image. You could use "hold on" as such:

hold on
plot ([L1.Lon],[L1.Lat], '-b');
xlim([-11 3]);
ylim([49 61]);

The resolution of the image (x pixels vs y pixels) and the coordinates of the plot (latitude vs longitude range) may not match. You may need to scale it.

[Jonathan Demmer]

Dear kevin,

Thank you for your answer. I manage to make the whit areas as i wanted. I change xlim and ylim to fit the matrice correspnding to the data. However, it seems that the border of UK and Ireland are push on the top left corner (see picture attached). I dont understand how to brong back the border in the middle of the picture. Do oyu have any idea?

Cheers

[Kevin Holly]

If you are having difficulties lining up the axes. You could create two different axes and make the background and axes of the axes with the plot invisible.

ax1 = axes;
img = image;
colorbar
cmap = turbo;
cmap(1:4,:)=ones(4,3);
colormap(cmap)

ax2 = axes;
plot(50*rand(7,7))
ax2.Color='none';
ax2.Position = ax1.Position;
axis off

[Jonathan Demmer]

Thankj yo uvery much it works!!!