KPG1_GRAPH

Draws a line graph

Description:

Opens a graphics device and draws a graph displaying a supplied set of points. Each point is defined by an X and Y value, plus an optional error bar. An AST Plot is returned so that the calling application can add further graphics to the plot if needed. When complete, the calling application should annul the Plot, and close the workstation:

CALL AST_ANNUL( IPLOT, STATUS ) CALL AGP_DEASS( ’ DEVICE’ , .FALSE., STATUS )

Various environment parameter names are used by this routine, to encourage uniformity in parameter naming, and behaviour. See KPG1_GRPHW for details.

Invocation

CALL KPG1_GRAPH( N, X, Y, NSIGMA, YSIGMA, XLAB, YLAB, TTL, XSYM, YSYM, MODE, NULL, XL, XR, YB, YT, APP, QUIET, LMODE, BSCALE, IPLOT, STATUS )

Arguments

N = INTEGER (Given)
Number of points
X( N ) = REAL (Given)
X value at each point. These are scaled by the value supplied in BSCALE(1) to generate the axis labels.
Y( N ) = REAL (Given)
Y value at each point. These are scaled by the value supplied in BSCALE(2) to generate the axis labels.
NSIGMA = REAL (Given)
Controls the length of the vertical error bars. A value of zero suppresses error bars. Otherwise error bars are drawn which extend by from Y - NSIGMA∗YSIGMA to Y + NSIGMA∗YSIGMA.
YSIGMA( N ) = REAL (Given)
The standard deviation associated with each Y value.
XLAB = CHARACTER ∗ ( ∗ ) (Given)
A default label for the X axis. Only used if the user does not supply an alternative. Trailing spaces are ignored. If a Plot is supplied via IPLOT, then the " Label(1)" attribute in the Plot is used as the default in preference to XLAB.
YLAB = CHARACTER ∗ ( ∗ ) (Given)
A default label for the Y axis. Only used if the user does not supply an alternative. Trailing spaces are ignored. If a Plot is supplied via IPLOT, then the " Label(2)" attribute in the Plot is used as the default in preference to YLAB.
TTL = CHARACTER ∗ ( ∗ ) (Given)
A default title for the plot. Only used if the user does not supply an alternative. If a Plot is supplied via IPLOT, then the " Title" attribute in the Plot is used as the default in preference to TTL.
XSYM = CHARACTER ∗ ( ∗ ) (Given)
The default symbol for the horizontal axis. Only used if the user does not supply an alternative. This will be stored with the Plot in the AGI database and (for instance) used by CURSOR as axis symbols when displaying the cursor positions on the screen. If a Plot is supplied via IPLOT, then the " Symbol(1)" attribute in the Plot is used as the default in preference to XSYM.
YSYM = CHARACTER ∗ ( ∗ ) (Given)
The default symbol for the horizontal axis. Only used if the user does not supply an alternative. This will be stored with the Plot in the AGI database and (for instance) used by CURSOR as axis symbols when displaying the cursor positions on the screen. If a Plot is supplied via IPLOT, then the " Symbol(2)" attribute in the Plot is used as the default in preference to XSYM.
MODE = INTEGER (Given)
Determines the way in which the data points are represented: 1 - A " staircase" histogram, in which each horizontal line is centred on the X position. Bad values are flanked by vertical lines drawn down to the lower edge of the viewport. 2 - The points are joined by straight lines. 3 - A marker is placed at each point (see MTYPE). 4 - (not used) 5 - A " chain" in which each point is marker by a marker and also join by straight lines to its neighbouring points. 6 - The same as Mode 1, except that bad values are not flanked by vertical lines drawn down to the lower edge of the viewport (a simple gap is left instead). 7 - The data points are not drawn.
NULL = LOGICAL (Given)
If .TRUE., then the user may supply a null (!) value for most of the parameters accessed by this routine to indicate that nothing is to be plotted. In this case, no error is returned. Otherwise, a PAR__NULL error status is returned if a null value is supplied.
XL = REAL (Given)
The default value for the XLEFT parameter. If VAL__BADR is supplied, the minimum of the X values is used (plus a small margin).
XR = REAL (Given)
The default value for the XRIGHT parameter. If VAL__BADR is supplied, the maximum of the X values is used (plus a small margin).
YB = REAL (Given)
The default value for the YBOT parameter. If VAL__BADR is supplied, the minimum of the low end of the Y error bars is used (plus a small margin).
YT = REAL (Given)
The default value for the YTOP parameter. If VAL__BADR is supplied, the maximum of the high end of the Y error bars is used (plus a small margin).
APP = CHARACTER ∗ ( ∗ ) (Given)
The name of the application in the form " <package >_ <application >" . E.g. " KAPPA_NORMALIZE" .
QUIET = LOGICAL (Given)
If .FALSE., a message is displayed indicating the number of points which were plotted. If .TRUE., nothing is displayed on the alpha screen.
LMODE = LOGICAL (Given)
If .TRUE., then the user is given the chance to specify the default vertical bounds for the plot using parameter LMODE. If .FALSE., the supplied bounds (YB, YT ) are used, and the eqivalent of " Extended" LMODE is used for any bounds which are not supplied.
BSCALE( 2 ) = DOUBLE PRECISION (Given)
Scale factors which converts the supplied (x,y) values into the values to label on the plot. A similar BZERO argument could be added if there is ever a need.
IPLOT = INTEGER (Given and Returned)
On entry, this can either be AST_NULL or a pointer to a two-dimensional Frame. If AST__NULL, the supplied values for the XLAB, YLAB, TTL, XSYM and YSYM arguments are used without change. If a Frame is supplied, the Label, Title, Units and Symbol attributes of the Frame are used in preference to XLAB, YLAB, TTL, XSYM and YSYM (which are then ignored). Any supplied Frame pointer is annulled before returning, and a pointer to the Plot used to draw the axes is returned.
STATUS = INTEGER (Given and Returned)
The global status.

Notes: