Finding number of data points in a single grid?

3 次查看（过去 30 天）
Atiqah Zakirah
Atiqah Zakirah 2017-5-30
评论： Atiqah Zakirah 2017-5-30
I have a data set of consisting of latitude and longitude coordinates. After plotting my grid and the coordinate points, I want to determine the number of points within a single grid. This is my code so far. However, it can only create the grid and plot the points. It's unable to determine the number of points in a grid. Any idea why my code isn't doing what I want? Thanks in advance.
%%create grid
N = 31; % creates a 30x30 grid
xgrid = linspace(103.6,104,N);
ygrid = linspace(1.25,1.5,N);
[X,Y] = meshgrid(xgrid,ygrid);
figure
hold on
plot(X,Y,'r');
plot(X',Y','r');
xlim([103.6 104])
ylim([1.25 1.5])
%%plot coordinate points
plot(coordinates(:,2),coordinates(:,3),'.');
%%find number of bus stops in a single grid
lat = coordinates(:,2); % x coordinates
lon = coordinates(:,3); % y coordinates
% create nested for loop
for i = linspace(103.6,104,(1/75))
for j = linspace(1.25,1.5,(1/120))
% index = row number
index = find(lat > i & lat < i + 1 & lon > j & lon < j + 1);
% stn = data point
stn = coordinates(index,1);
end
end

请先登录，再回答此问题。

回答（1 个）

Musa
Musa 2017-5-30
Atiqah,
coordinates isn't defined.
  1 个评论
Atiqah Zakirah
Atiqah Zakirah 2017-5-30
Hey Musa,
My coordinates were from an excel file. I imported the data into Matlab as a numeric matrix called "coordinates" so there isn't a line of code that defines what the coordinates are since there's too many. Must I define it in another way?

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Matrix Indexing 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by