The ornamental design for a coordinate inputinstrument, as shown and described.
FIG. 1 is a front-bottom-right perspective view of a coordinate input instrument according to an embodiment of my new design;
FIG. 2 is a rear-top-left perspective view thereof;
FIG. 3 is a front elevational view thereof;
FIG. 4 is a right side elevational view thereof, wherein the left side elevational view is a mirror image of the right side elevational view;
FIG. 5 is a rear elevational view thereof;
FIG. 6 is a top plan view thereof;
FIG. 7 is a bottom plan view thereof;
FIG. 8 is a partial front-bottom-right perspective view thereof indicated in FIG. 1; and,
FIG. 9 is a partial front elevational view thereof indicated in FIG. 3.
The dot-dot-dash broken lines indicate the boundary of the enlarged portions of the drawings. The remaining broken lines in the figures depict portions of the coordinate input instrument that form no part of the claimed design.