comments added

bigdata.m

@@ -28,14 +28,14 @@ handles.dataset = 'o3_surface_20180701000000.nc';
 handles.lon = ncread(handles.dataset, 'lon'); handles.nx = length(handles.lon);
 handles.lat = ncread(handles.dataset, 'lat'); handles.ny = length(handles.lat);
 handles.time = ncread(handles.dataset, 'hour');
-handles.ozone = 'chimere_ozone';
-handles.currentTime = 1;
+handles.ozone = 'chimere_ozone';   %default ozone to be displayed as first
+handles.currentTime = 1;   %default hour set to 1
 handles.hour = ncread(handles.dataset, handles.ozone,[1 1 handles.currentTime],[handles.nx handles.ny 1]);
 
-map = pcolor(handles.lon, handles.lat,handles.hour');
-map.EdgeAlpha=0;    %changes the transparency to 0
-load coastlines;
-line(coastlon,coastlat);
+map = pcolor(handles.lon, handles.lat,handles.hour');   %draws the data with pcolor
+map.EdgeAlpha=0;   %changes the transparency to 0
+load coastlines;      
+line(coastlon,coastlat);   %outlines the land contours to make the map easier to see
 
 % Choose default command line output for bigdata
 handles.output = hObject;
@@ -65,7 +65,7 @@ handles.color_scheme = handles.color_schemes(val); %set the color_scheme variabl
 handles.hour = ncread(handles.dataset, handles.ozone,[1 1 handles.currentTime],[handles.nx handles.ny 1]);
 map = pcolor(handles.lon, handles.lat,handles.hour');
 map.EdgeAlpha=0;
-colormap(handles.color_scheme)
+colormap(handles.color_scheme)   %changes the colour of the map to the chosen one
 load coastlines;
 line(coastlon,coastlat);
 guidata(hObject, handles);
@@ -83,10 +83,10 @@ function slider_hour_Callback(hObject, eventdata, handles)
 
 
 val = get(hObject, 'val');
-val = round(val);
-handles.currentTime = val;
+val = round(val);   %rounds the value so that we only get integers 
+handles.currentTime = val;  %assigns current time to the value set on slider
 
-set(handles.hourtext,'String',num2str(val));
+set(handles.hourtext,'String',num2str(val));   %prints out the value on slider above it
 
 handles.hour = ncread(handles.dataset, handles.ozone,[1 1 handles.currentTime],[handles.nx handles.ny 1]);
 map = pcolor(handles.lon, handles.lat,handles.hour');