The ornamental design for a coordinate inputinstrument, as shown and described.
FIG. 1 is a front perspective view of a coordinate input instrument according to a representative embodiment of my new design;
FIG. 2 is a rear perspective view of the coordinate input instrument shown in FIG. 1;
FIG. 3 is a side view of the coordinate input instrument shown in FIG. 1, the side opposite of the side shown in FIG. 3 being a mirror image thereof and therefore not shown;
FIG. 4 is a front view of the coordinate input instrument shown in FIG. 1;
FIG. 5 is a rear view of the coordinate input instrument shown in FIG. 1;
FIG. 6 a top view of the coordinate input instrument shown in FIG. 1; and,
FIG. 7 is a bottom view of the coordinate input instrument shown in FIG. 1.
The broken lines show portions of the coordinate input instrument which form no part of the claimed design.