range different longitude and latitude geoshow

I have longitude 112 to 114 and latitude -6.8 to -7.4.I am trying to range the longitude and latitude from geoshow, but somehow it doesnt change much

close all ;
clear;
data1 = shaperead ( 'data.shp' ); % polygon data
geoshow (data1)
u = shaperead ( 'points.shp' , 'UseGeoCoords' , true)   % point data of 3050x1
h = geoshow (u, 'Marker' , 'o' , ...
            'MarkerEdgeColor' , 'g' , ...
            'MarkerSize' , 6)
legend ([h], 0.5, 'ok' );        

so data1 is the shapefile of polygon and u are the point location.I wanted to make the longitude and latitude is range by 0.5 or 1 in geoshow? Inside file u it contains Geometry = 'point', Lon (Longitude) and Lat (Latitude ).

I try to edit in legend but it shows:

Error using legend> process_inputs (line 554)

Invalid argument.Type 'help legend' for more information.

[darova]

Please attacht the data. Can you make a simple drawing of what you are trying todo? The qustion is unclear

Answer 1

[muhammad iqbal habibie]

As you seen from my attachment the differences of each longitude on the x axes and latitude on the y axes is not same. I would like to make it range 0.5 examples for longitude starts 112 then 112.5,then 113. and also latitude start from -6.8 then -6.85 then -6.9. I try above to edit from the legend but it has an error. Beside the range 0.5 maybe can modified the range to other 0.01. Hopefully it is possible. Because when I read the shapefile from data1 it direct show,maybe can possible to change the range of longitude and latitude.

Answer 2

[darova]

Here is my idea

Use meshgrid to create a grid (red points)

Use inpolygon to choose points inside map (blue circles)

[muhammad iqbal habibie]

Thank you for your idea. This is good for creating the points. But I want to edit the range of the longitude or latitude either the differences is 0.5 or can be modified yourself. For examples from the picture shows the longitude 112 to 112.6 and the differences is 0.1 as well as the latitude, is it possible can modified the range beside automatically loading from the data shapefile?

[darova]

try this

latstart = 112;
lonstart = -7.5;
step = 0.5;
newlat = round((lat-latstart)/step)*step + latstart;
newlon = round((lon-lontart)/step)*step + lonstart;

Some duplicate values may appear. You can remove them

[~,ix1] = unique(newlat);
[~,ix2] = unique(newlon);
ix = unique([ix1(:);ix2(:)]);
newlat = newlat(ix);
newlon = newlon(ix);

Answer 3

[Sean de Wolski]

Look at bufferm https://www.mathworks.com/help/map/ref/bufferm.html. Call that on your data and then just take the bounds() of it.

[muhammad iqbal habibie]

Any examples to use if my longitude and latitude it belongs from the shapefile of data1 using bufferm? thank you