How to define an area with 1s to use 'areamat' function
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Hello,
I am planning to use areamat function to calculate total area of african continent. I have set of lat lon data (set of data separated with NaN NaN). As areamat function calculate area of the region defined by 1s or zeros i want to say,
for all the values >=min(lon) and >=min(lat) and <=max(lat) and <=max(lat) are
africa = (those values).
i have not use this function before. So i am not sure if I misunderstood this funstion either.
I would truly appreciate if anyone could help me with this funtion and write a condiction as above.
Thank you!!
2 Comments
dpb
on 23 Oct 2022
The area defined by min(lon) <= valX <= max(lon) and min(lat) <= valY <= max(lat) is a rectangular area that won't represent the actual continent of Africa all that well.
You'll have to have a boundary definition somewhere to ascertain whether a given coordinate pair is/is not within that area -- which would be what having the definition of the input array to areamat would give you if you had it already...but the above logic won't help you generate one, unfortunately.
I don't have mapping TB but there appears to be a dataset included in it -- let's just try something...
load coastlines
hM=worldmap('Africa');
geoshow('landareas.shp', 'FaceColor', [0.15 0.5 0.15])
Well, that gives an outline; there's example code that shows how stuff is broken down inside the coastlines lat, lon data, but I don't know at this point how one determines being in/out of the continent...
Good luck...
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