x1: The horizontal position of the line's start point relative to the upper-left corner of the canvas (0, 0). The default is zero
y1: The vertical position of the line's start point relative to the upper-left corner of the canvas (0, 0). The default is zero
x2: The horizontal position of the line's end point relative to the upper-left corner of the canvas (0, 0). The default is 100
y2: The vertical position of the line's end point relative to the upper-left corner of the canvas (0, 0). The default is 100
color: The line's color. This must be a string holding triple hexadecimal values representing the red, green, and blue components for a color. The default is "000000" (black)
alpha: The line's transparency value. Valid values are 0 (fully transparent) to 100 (fully opaque). The default is 100
thickness: The line's thickness. The default is 1 pixel
Example
<gauge>
<!-- draw a red line -->
<line x1='50'
y1='50'
x2='300'
y2='200'
color='ff0000'
alpha='100'
thickness='10'
/>
<!-- draw a green line -->
<line x1='200'
y1='75'
x2='100'
y2='200'
color='00ff00'
alpha='75'
thickness='20'
/>
</gauge>