1. An information processing apparatus having a gesture editing function comprising: a display screen for displaying document information; position indicating means for indicating a position on said display screen; position detecting means for detecting a coordinate of a handwritten point or coordinates of a handwritten line drawing on said display screen, the handwritten point or line drawing being drawn using said position indicating means; first memory means for storing a plurality of different coordinate systems used in computing a position of a displayed character or character string, wherein a position of a point of origin on the display screen of each different coordinate system differs depending on the coordinate system; second memory means for storing reference strokes and edit instructions so as to have an association between each pair of reference strokes and edit instructions; gesture judging means for judging a given edit instruction based on a result of a comparison between a shape of the handwritten line drawing and the reference stroke stared in said second memory means when an editing position for editing the document information is specified by the handwritten line drawing; position computing means for selecting one of the different coordinate systems from said first memory means based on the given edit instruction and for computing a position of a character or character string corresponding to the editing position using a coordinate of the handwritten line drawing and the selected coordinate system; and document editing means for editing a character or character string at the computed position based on the given edit instruction.
4. The information processing apparatus having a gesture editing function as set forth in claim 1, wherein said position indicating means includes a pen input device for use in specifying a position on said display screen by pointing and in inputting information by handwriting.