How do I plot error bars for say, every 100th point, instead of for every single point? At the moment my plot looks like a thick band instead of a thin curve, since every point has an error bar attached to it.

Any help is appreciated, thanks.

First, I've never used xmgrace, so take any advice I give you with caution. Having said that, I find no option in the xmgrace man page to parse data points going into xmgrace.

Second, since you say nothing about your operating system, nor anything about the data source used to input data into xmgrace, I am left with the only option of using the WAG method of offering advice (WAG = wild assed guess).

I assume you have a database of some sort to hold the data you will feed into xmgrace. Why not first extract every 100th value into a seperate file, then feed that into xmgrace?

It's alright I figured out how to do it. Click on Plot >> Set Appearance >> Symbols. Then set the 'symbol skip' setting