1. A non-transitory computer-readable storage medium having stored therein a coordinate processing program for processing input coordinate data outputted from a coordinate input device, the coordinate processing program causing a computer to operate as: a second coordinate series calculator configured to calculate, on the basis of a first coordinate series indicated by the input coordinate data, a second coordinate series which represents an input trajectory having a shape smoother than a shape of an input trajectory represented by the first coordinate series; a moving amount calculator configured to calculate a moving amount of a coordinate on the basis of the first coordinate series; a moving direction calculator configured to calculate a moving direction of the coordinate on the basis of the second coordinate series; and a processing section configured to perform predetermined processing by using the moving amount calculated by the moving amount calculator and the moving direction calculated by the moving direction calculator, wherein the moving direction calculator calculates the moving direction on the basis of a direction of a straight line connecting a latest coordinate of the second coordinate series to a coordinate immediately previous to the latest coordinate.