# ncl_agcurv - Man Page

Draws a curve in a manner specified by the current values of the control parameters — the primary parameters with default values or with values supplied by the user, and the secondary parameters with values computed by AGSTUP.

## Synopsis

CALL AGCURV (XVEC,IIEX,YVEC,IIEY,NEXY,KDSH)

## C-Binding Synopsis

#include <ncarg/ncargC.h>

void c_agcurv (float *xvec, int iiex, float *yvec,

int iiey, int nexy, int kdsh)

## Description

- XVEC
(a singly-subscripted input array of type REAL), when IIEX is non-zero, contains NEXY X-coordinate data - curve point 1 has X coordinate XVEC(1), curve point 2 has X coordinate XVEC(1+IIEX), curve point 3 has X coordinate XVEC(1+IIEX*2), etc. When IIEX is zero, the array XVEC is ignored - curve point 1 has X coordinate "1.", curve point 2 has X coordinate "2.", etc.

If the value of any X coordinate matches the current value of 'NULL/1.' (default - "1.E36"), the corresponding point is considered to be missing - curve segments on either side of that point are not drawn.

- IIEX
(an input expression of type INTEGER), if non-zero, is the index increment between one X coordinate in XVEC and the next. If IIEX is zero, the array XVEC is ignored, as described above.

- YVEC
(a singly-subscripted input array of type REAL) is just like XVEC, but provides Y coordinate data.

- IIEY
(an input expression of type INTEGER) is just like IIEX, but describes the use (or non-use) of YVEC.

- NEXY
(an input expression of type INTEGER) is the number of curve points - the number of X/Y coordinate pairs to be used.

Note: If 'INVERT.' is given the value "1." (in place of its default value "0."), AGCURV will behave as if the arguments XVEC and IIEX had been interchanged with the arguments YVEC and IIEY, so that X-coordinate values refer to vertical distances, and Y-coordinate values to horizontal distances, on the graph. This parameter affects AGSTUP in a similar manner, thus allowing one to plot "X as a function of Y".

- KDSH
(an input expression of type INTEGER) specifies the dashed-line pattern to be used in drawing the curve. (Since the routines DASHD, FRSTD, VECTD, and LASTD, in the package Dashline, are used to draw the curve, it may have its own particular dashed-line pattern.) If KDSH is zero, the user is assumed to have done his own call to DASHD; AGCURV will do no such call.

- If KDSH is zero, the user is assumed to have done his own call to DASHD; AGCURV will do no such call.
- If KDSH is non-zero and negative, the function MOD(-KDSH-1,26)+1 determines which of 26 "alphabetic" patterns is to be used; each of these generates a solid line interrupted by one of the letters of the alphabet. The value 1 implies that an "A" will be used, the value 2 that a "B" will be used, . . . the value 27 that an "A" will be used again, etc.
- If KDSH is non-zero and positive, the function MOD(KDSH-1,n)+1 determines which of n "user" patterns is to be used; these n patterns are defined by the parameters in the group named 'DASH.' - the default values specify one solid-line pattern.

Note: The routines EZY and EZXY, which draw one curve per call, always call AGCURV with KDSH = 1. The routines EZMY and EZMXY, which draw one or more curves per call, call AGCURV with KDSH = ISIGN(p,q), where p is the number of the curve being drawn (p is between 1 and MANY, inclusive) and q is the current integral value of 'DASH/SELECTOR.'.

## C-Binding Description

The C-binding argument descriptions are the same as the FORTRAN argument descriptions.

## Examples

Use the ncargex command to see the following relevant example: agex13.

## Access

To use AGCURV or c_agcurv, load the NCAR Graphics libraries ncarg, ncarg_gks, and ncarg_c, preferably in that order. To get smoother curves, drawn using spline interpolation, also load libdashsmth.o. Or, you can use the ncargf77 command to compile your program and load the above libraries, then, to get smoother curves, use the -dashsmth option.

## Messages

See the autograph man page for a description of all Autograph error messages and/or informational messages.

## See Also

Online: autograph, agback, agbnch, agchax, agchcu, agchil, agchnl, agdshn, aggetc, aggetf, aggeti, aggetp, aggetr, agpwrt, agrstr, agsave, agsetc, agsetf, agseti, agsetp, agsetr, agstup, agutol, anotat, displa, ezmxy, ezmy, ezxy, ezy

Hardcopy: NCAR Graphics Fundamentals, UNIX Version

## Copyright

Copyright (C) 1987-2009

University Corporation for Atmospheric Research

The use of this Software is governed by a License Agreement.