Hi guys,
I'm new to inkscape but I've just started to use it to try and edit some .eps images that I've generated using matlab. I have one figure that involves a 2-D plot of a curve, consisting of a few hundred datapoints. I would like to add an arrowhead to the middle of the curve. I have tried to go to the Object menu and select Fill and Stroke. However, when I select the curve and add mid-marker arrow heads in Stroke style, it adds arrow heads to every single datapoint. I would just like to add an arrow to the middle point in the curve. How can I do this?
Thanks!

Welcome to InkscapeForum!

It's hard to say what the best "workaround" would be, without seeing the image. I'm thinking you could break the path at that point, and use either an end marker on one piece or a start marker on the other. However there may be reasons why breaking the path wouldn't work. Or maybe you could duplicate the path and break it at that place, and apply the marker to it, then just delete the other piece (if there is one). Or if those ideas don't work, could you show us a screenshot?

I stay away from using the built-in markers as they're not configurable enough and usually end up at the wrong angle. There was one other gotcha with markers which I can't remember right now but it got me when i did want to use them in a workflow for some data illustrations. The heat must be getting to me because I also can't remember the name of one of the forum regulars who makes really nice illustrations for inkscape tutorials. Anyway, the style and techniques lend themselves very well to data/graph illustrations.

The most obvious answer to me, for one (1) arrowhead, is to just draw it and plonk it in place. Almost no automatic method is going to be faster - the only other possibility is that the next release will have symbol libraries and then someone could make and upload a nice arrows symbol library that you could use. I am putting together a math symbols library that is quite handy even with just a few elements...

That's probably druban you're thinking of!

(Heat, huh? Well, soon enough, you'll be cold and I'll be hot!)

Thanks Brynn, it is Druban who does those excellent illustrations, for example here viewtopic.php?f=5&t=10219&p=41530#p41530
It's pretty strange seasons here in Melbourne. Cold weather is roughly from May right thru to December, which is when summer starts. We've had Christmas stinking hot or jumper wearing weather. My tomatos are two months late. At least we've got a family loaned above ground pool for those hot days.