PGPLOT Module: PGERRB -- horizontal or vertical error bar


SUBROUTINE PGERRB (DIR, N, X, Y, E, T)
INTEGER DIR, N
REAL X(*), Y(*), E(*)
REAL T

Plot error bars 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.


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).
N (input) : number of error bars to plot.
X (input) : world x-coordinates of the data.
Y (input) : world y-coordinates 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.

Note: the dimension of arrays X, Y, and E must be greater
than or equal to N. If N is 1, X, Y, and E may be scalar
variables, or expressions.