As mentioned above, the gr_copy routine can be used for clipping. Therfor an interval must be specified. This can be done in two differnt ways: Intervals may be specified by -i min_x_value max_x_value or by specifying -s startpoint -e endpoint. When specifying the point number, take into account, that the first point in every set has the number zero, like it is usual in the programming language C.
All actions will be performed for the points inside the interval only. Points outside the interval borders will be printed out unchanged. It is possible to turn of the output of the points outside the interval by using the option -c with no additional argument.
gr_copy -test.dat -i -0.5 .5 -c
will perform the clipping: Only points inside the x-interval between 0.5 0.5 are printed out.
It is possible to specify different intervals for different sets. Therfor specify the set number after the -i, -s or -e option.
gr_copy -test.dat -s2 4 -c
will not print the first for points in the third set (Recognize, that the counting of the points and sets starts with 0)