Plot figure for certain elements of readtable output

Hi,

I have a readtable output, T, = (for example):

Longitude | Latitude

1 34

1 56

1 57

4 72

4 44

4 124

I want to plot a graph of Long vs Lat but only for Long = 1 (so the coordinates of this graph will be: (1, 34), (1, 56), (1, 57).

I tried this code but it just gives me a matlab crash report, I assume cause it requires a lot of iterations for my actual readtable output. Also, I just end up getting a bunch of empty figures:

for long_ind = numel(T{1,1}.Longitude)

while T{1,1}.Longitude(long_ind,1)==1

figure

plot(T{1,1}.Longitude(long_ind,1),T{1,1}.Latitude(long_ind,1))

hold on

end

end

Thank you

Answer 1

[Jonas]

you can use directly index the variables of the table:

tbl=table();
tbl.long=[1 2 3 4 4 4];
tbl.lat=[34 56 57 72 44 124];

myCond=tbl.long<=3; % change as you want

plot(tbl.long(myCond),tbl.lat(myCond));

Answer 2

[Abderrahim. B]

Hi!

As per my understading of your question, the code below should work:

%% Create table with 2 variables (Log and Lat)
data = table([1 1 1 4 4 4].', [34 56 57 72 44 124].' , 'VariableNames',["Long", "Lat"]) ;
long = data.Long; 
lat = data.Lat ;

%% Plot Long vs Lat (Long = 1)
figure
hold on

plot([lat(long == 1) lat(long == 1)], [long(long ==1) long(long == 1)],'r' )

Bonus: The below lines of code are just to make plot more readable

% Add coordinates as "points" using satter func
scatter([lat(long == 1) lat(long == 1)], [long(long == 1) long(long == 1)], 'filled')

offset = 0.1 ; % just to not overlap point with text
% Plot annotation
text( lat(long == 1) ,long(long == 1) + offset, strcat( num2str(long(long == 1)), ',' ,num2str(lat(long == 1))  ))
xlabel Latitude
ylabel Longitude
title ("Long vs Lat (Long = 1)")

Hope this help