poles

Hi, I've been playing with REW and noticed there's a display titled 'Zeros and Poles' so I'm assuming that's referring to the zeros and poles of some analytic function. Is there a description of this function and what the plot tells you I could understand? I was an algebraic geometer at one...

Has anyone every made or seen a DIY screen that is stretched using fibergalss tent poles/rods? If it would work with all poles or possible with to rigid poles and two "bendy" poles to strech the material, it would make storing the screen a lot easier for non-fixed installations. Seems easy...