PGPLOT Module: PGERR1 -- horizontal or vertical error bar


SUBROUTINE PGERR1 (DIR, X, Y, E, T)
INTEGER DIR
REAL X, Y, E
REAL T

Plot a single error bar in the direction specified by DIR.
This routine draws an error bar only; to mark the data point at
the start of the error bar, an additional call to PGPT is required.
To plot many error bars, use PGERRB.


Arguments
DIR (input) : direction to plot the error bar relative to
the data point.
One-sided error bar:
DIR is 1 for +X (X to X+E);
2 for +Y (Y to Y+E);
3 for -X (X to X-E);
4 for -Y (Y to Y-E).
Two-sided error bar:
DIR is 5 for +/-X (X-E to X+E);
6 for +/-Y (Y-E to Y+E).
X (input) : world x-coordinate of the data.
Y (input) : world y-coordinate of the data.
E (input) : value of error bar distance to be added to the
data position in world coordinates.
T (input) : length of terminals to be drawn at the ends
of the error bar, as a multiple of the default
length; if T = 0.0, no terminals will be drawn.