4 replies to this topic

[lauraf]

Hi all,

I am starting working on the Illustrator cs4/mapubisher 8 package and I have read this nice forum for some time, before deciding to post my first question (two, actually).
The problem is the following: I have many linear features (straight) and need to measure their azimuth. Illustrator seems to measure angles anticlockwise starting from east: I suppose it is not possible to modify this setting and make it measure from north and clockwise, is it?
Second, I would like to have the azimuth automatically calculated in the attributes of my linear features, maybe deriving the value from some sort of expression, but I am not able to find any "angular field" associated to lines, instead it seems to work with point features ("rotation" field)... what am I doing wrong?

Maybe my questions are naive, but consider I am new to cartography, so please answer in a simple way!

Thank you so much for help in advance!

[Hans van der Maarel]

The problem is the following: I have many linear features (straight) and need to measure their azimuth. Illustrator seems to measure angles anticlockwise starting from east: I suppose it is not possible to modify this setting and make it measure from north and clockwise, is it?

No. The math to calculate between the two is not terribly difficult though. New azimuth = (old azimuth - 90) * -1

So a straight north-south line, azimuth -90 according to Illustrator would get a new azimuth of 180

Second, I would like to have the azimuth automatically calculated in the attributes of my linear features, maybe deriving the value from some sort of expression, but I am not able to find any "angular field" associated to lines, instead it seems to work with point features ("rotation" field)... what am I doing wrong?

You're not doing anything wrong, MAPublisher simply isn't tracking the azimuth of a line. The reason behind this (at least as far as I know, as I'm not involved with the development) is that line attributes are stored for the entire line, but the azimuth may change for every line segment, as every segment of a line may have a different direction. Now, you only have single-segment lines, but MAPublisher's data model has to accomodate for multiple-segment lines too.

If you could somehow get the coordinates of the start- and endpoint of the line you could do the math yourself using an expression within MAPublisher.

Just wondering, what do you need this azimuth for? Do you have access to other software that could be used to calculate it?

[lauraf]

Thanks, you're right, math is easy, I was just wondering if it was possible, to set up my first project correctly!

Regarding line azimuths, now that you are telling me about multi-segment lines, it sounds clear. I should have thought about that.

The reason why I need the azimuth is the following: my line segments correspond to fault traces (intersections between rupture planes and earth surface) that I draw after a satellite image or aerial photo of a region. The azimuths are involved in the statistics of the data, i.e. to detect peaks of fault attitude (N - S, or E -W and so on...).
Up to now we used to print the document and measure the fault azimuths, but the procedure is time-consuming, and I have been told that some GIS programs (like ArcGis I guess) are able to do that. But unfortunately I have not access to it, just MAPublisher

Thanks again, every suggestion to solve this problem is highly appreciated!

[Hans van der Maarel]

I put in a feature request with Avenza to be able to get the start- and endpoint coordinates of a line as attributes in MAPublisher. Hopefully they're going to be able to add this soon.

[lauraf]

I put in a feature request with Avenza to be able to get the start- and endpoint coordinates of a line as attributes in MAPublisher. Hopefully they're going to be able to add this soon.

This would be great! Thanks again for your interest.