View a shapefile, then plot points with lat/long?

Hi,

I have a shapefile of the San Francisco Bay Area, which I am reading into Matlab using the following:

S = shaperead('bayarea_general.shp');

I can then view a map of the shapefile using:

mapshow(S)

That all works fine, however, my map is not in lat/long degrees. I would like it to be, since I have a list of points with associated lat/long coordinates. I thought the map might be in UTM, so I converted my data to UTM but that doesn't plot correctly.

My questions are:

1) How do I figure out the coordinate system that my shapefile is in?

2) How do I convert either the shapefile, or my own lat/long data to be in the same format/coordinate system?

Thanks!

Answer 1

[Harsh Mahalwar]

Hey Niky,

You can figure out the coordinate system of a shapefile using the shapeinfo function!

sInfo= shapeinfo('bayarea_general.shp');

sInfo.CoordinateReferenceSystem

For more information on shapeinfo function you can checkout the following documentation.

https://in.mathworks.com/help/map/ref/shapeinfo.html

In order to convert the shapefile and your lat, long data in the same format, you can read the shapefile using the readgeotable function (which copies your shapefile into a MATLAB structure variable).

saveGeoTable = readgeotable('bayarea_general.shp');

For more information on readgeotable function you can checkout the following documentation.

https://in.mathworks.com/help/map/ref/readgeotable.html

If your lat, long are stored in a csv file, you can read a csv file using readtable function (which copies your csv file into a MATLAB structure variable).

saveTable = readtable("lat_long.csv")

For more information on readtable function you can checkout the following documentation.

https://in.mathworks.com/help/matlab/ref/readtable.html?searchHighlight=readtable&s_tid=srchtitle_readtable_1

This is one of the ways in which you can have these 2 types of data in the same format.

Thanks and regards,

Harsh Mahalwar