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select a range of elements from a nested list
Posted:
Dec 2, 1996 10:27 AM


Hi MathGroup
Say you have a nested list like that {{x1,y1},{x2,y2},{x3,y3},...{xn,yn}} basically containing X and Y values for a XY plot in each element. The X values span a range from say 0 to 0.4 and you ONLY want to select the elements (x,y values) from the list for which the x value spans say 0 to 0.3. BUT you don't want to COUNT the elements (visually on the screen) and figure out the position at which the x value is just greater than 0.3 and then subtract 1 from this position.
I still want do define the list by using
Table[list[[x,1]],list[[x,2]],{x, 1, ZZZ}]
here ZZZ means the number for which the x value <= 0.3, this number needs to be found by MATHEMATICA!
I like to know if there is a general procedure to select elements from a nested list based on the values of one member of the elements of that nested list.
I hope I made myself clear enough to you all.
Thanks a lot.
Oliver Schurr Department of Chemistry Georgetown University Washington, DC 20057



