polybuffer distance in meters?

Hello,

I guess this one is pretty simple, but I can't find any information on that topic.

In the formula polyout = polybuffer(P,'lines',d) the "d" stands for the Buffer distance, specified as a numeric scalar.

I have polygons specified by UTM coordinates and I'd like to get a buffer of 10 meters around the polygon. And I guess I can't just use polyout=polybuffer(P,'lines', 10), because the formula uses d as a numeric scalar and not a metric unit. So how to get the buffer of 10 meters? :D

Kind regard

Alex

Answer 1

[Chad Greene]

I think you've got it right, Alex, but this calls for an explanation of the phrase numeric scalar. The word numeric just means a number, and not a binary or a string (letters). The word scalar means just a single value, not a vector or a matrix.

The number 10 is numeric, and it's a scalar. The fact that it has units associated with it is okay, because the coordinates of P also have units associated with them. UTM is in meters, and your buffer length is also meters. As long as the units of your buffer are the same as the units of the P coordinates, you're alright.

To check, I would plot P and your buffered version of P on the same plot like this:

plot(P)
hold on
P_b =polybuffer(P,'lines', 10);
plot(P_B)

Then zoom in and visually confirm that the two polygons are separated by 10 m.

[Alexandra Kopaleyshvili]

Thank you for the clarification, Chad!