Find a solution to a practical problem probably involving Buffer

[BaranISCEN]

#Buffer 

Hello,

I have a problem and wanted to share it with the community in order to see if anyone was eventually able to help me finding out a solution. I have actually a dataset composed of points and projected on a shapefile describing European countries.

My goal is the following : create a new shapefile, with zones specified 100 kilometers around the boarders in-between all the States, since I want to see if there are more points close to the boarders, or not.

I thought that Buffer would be a nice way to do it but didn't manage to find out how to practically do this. I converted the polygone shapefile once to line, and then used the function Buffer, but there is nothing appearing. I did the same without converting before.

Thank you very much a lot for your help,

[DanPatterson_Retired]

Here is a visual guide...

Define Projection... a Visual Guide

[BaranISCEN]

Thank you very much for this. I had actually a question.

I have a shapefile of the world, at a rather precise level (and sub-divisions) that is apparently undefined (when I add data to Gis). Plus, I have the dataset composed of points (long-lat) undefined also.

Therefore, I just put the two layers but either the first one is displayed or the second one, not both. I then tried to Define Projection by defining them either as World 1984 or a Projected one (Natural Earth) but I can't still display both layers.

Is that related to Define Projection ? Do I have to look in this direction to fix the problem ? Thanks a lot

[DanPatterson_Retired]

Don't use them... or find out what the coordinate systems are before you use the define projection tool.

There must be some metadata with the sources.

If you define something wrong... as my examples in the link show.. is what you get

[BaranISCEN]

Actually, the coordinate system specified in the file attached to the shapefile is World Mercator WGS184. I used the Define Projection with World Mercator. But still impossible to see the points in the meantime - despite the fact that if I add XY the points alone, no matter the definition, they are always displayed.

[DanPatterson_Retired]

World Mercator is a projected coordinate system... if it was defined as such, that is good.

As for the points... if they are in decimal degrees (ie longitude and latitude, with longitude as the X and latitude is the Y) they are probably unprojected and have a 

Geographic Coordinate system... like GCS WGS84  

They are different...

[BaranISCEN]

If I want to use fishnet later, I have better to put them both in a projected coordinate system? and use Project for the points ? 

Thank you very much for all! 

[BaranISCEN]

Also, if I may ask one last favor: ideally, I would have liked to exclude the points that are on the seaward side (and therefore not close to a border with another country). Is there any mean to exclude these points and let only those close to another country ?