C-PLOT

Scientific Graphics and Data Analysis

xhairs.4

X-windows crosshairs user function

SYNOPSIS

fn xhairs.4

DESCRIPTION

The xhairs.4 filters works in conjunction with the x11 filter to display a cross-hairs in the x11 plot window.

When the mouse cursor is in the x11 graphics window, pressing the right mouse button will bring up a small window. This window displays the position of the mouse cursor as long as the cursor is in the graphics window. The position is displayed in C-PLOT window and annotation units (see below), assuming that the plot position is the default size in the default orientation. A subsequent press of the right mouse button will hide the small window.

When the user function xhairs.4 is active, the small window will also display the mouse cursor position in data units and will correct the window and annotation units display for the current plot position and orientation. Pressing the left mouse button while the cursor is in the graphics window will cause a cross hairs and the x and y data values to be displayed at the nearest data point. Pressing the right mouse button while the mouse cursor is in the graphics window will take you out of xhairs.4.

When xhairs.4 is not active, the small window can continue to display the mouse cursor position in data units, although if the axis ranges or window size is changed with the wi command, the data units and annotation units displayed will not be correct.

Window coordinates are in C-PLOT centimeters, with the origin located in the lower-left corner of the landscape (unturned) or portrait (turned) page window. These are the same units used to define the corner of the plot window with the wi command.

Annotation coordinates also are in C-PLOT centimeters, but are measured from the top-left corner of the plot window. These are the same units that define the annotation position with the pn or zn commands.