Section 3: library functions
CURVED – Draws a curve through a sequence of points. SynopsisCALL CURVED (X,Y,N) C-Binding Synopsis#include <ncarg/ncargC.h> void c_curved (float *x, float *y, int n) DescriptionX (an input array of type REAL) defines the X user coordinates of the curve. Array X is of length N. Y (an input array of type REAL) defines the Y…
CURVE3 – Draws the projection of a curve defined by a sequence of points in 3-space. SynopsisCALL CURVE3 (U,V,W,N) C-Binding Synopsis#include <ncarg/ncargC.h> void c_curve3 (float *u, float *v, float *w, int n) DescriptionU,V,W (input arrays, dimensioned at least N, of type REAL) contain the U, V, and W coordinates, respectively, of the points defining the…
CURVE – draws the curve defined by a specified series of points in the user coordinate system. The "pen" (for subsequent calls to FRSTPT, VECTOR, PLOTIF, and PLOTIT) is left at the location of the last point in the curve. SynopsisCALL CURVE (PX,PY,NP) C-Binding Synopsis#include <ncarg/ncargC.h> void c_curve (float *px, float *py, int np) DescriptionPX…
CURVD – derivatives for 1D functions. SynopsisFUNCTION CURVD (T, N, X, Y, YP, SIGMA) This function calculates a derivative at a specified point using a spline under tension. CURV1 must be called prior to calling CURVD, and the values thus obtained used as input to CURVD. The derivative value is returned. DescriptionT (real, input) The…
CURV2 – 1D interpolation for non-periodic functions. SynopsisFUNCTION CURV2 (T, N, X, Y, YP, SIGMA) This function interpolates a value at a specified point using a spline under tension. CURV1 must be called prior to calling CURV2, and the values thus obtained used as input to CURV2. CURV2 returns the interpolated function value at the…
CURV1 – does set-up for CURV2. SynopsisCALL CURV1 (N, X, Y, SLP1, SLPN, ISLPSW, YP, TEMP, SIGMA, IER) DescriptionN (integer,input) The number of input data values. (N > 1) X (real, input) An array containing the abscissae for the input function. Y (real, input) An array containing the functional values of the input data —…
CUFY – Converts from user coordinates to fractional coordinates. Namespps_converters – A set of functions, each of which transforms a coordinate from one of the NCAR Graphics coordinate systems to another. The complete list of functions is as follows: CFUX, CFUY, CMFX, CMFY, CMUX, CMUY, CPFX, CPFY, CPUX, CPUY, CUFX, CUFY, KFMX, KFMY, KFPX, KFPY,…
CUFX – Converts from user coordinates to fractional coordinates. Namespps_converters – A set of functions, each of which transforms a coordinate from one of the NCAR Graphics coordinate systems to another. The complete list of functions is as follows: CFUX, CFUY, CMFX, CMFY, CMUX, CMUY, CPFX, CPFY, CPUX, CPUY, CUFX, CUFY, KFMX, KFMY, KFPX, KFPY,…
CSVOROD – calculate Voronoi polygons for data on a sphere. SynopsisCALL CSVOROD (NPTS, RLATI, RLONI, NI, NF, IWK, RWK, NC, RLATO, RLONO, RC, NCA, NUMV, NV, IER) DescriptionNPTS (integer,input) The number of input data points (NPTS > 3). RLATI (double precision, input) An array containing the latitudes of the input data, expressed in degrees. The…
CSVORO – calculate Voronoi polygons for data on a sphere. SynopsisCALL CSVORO (NPTS, RLATI, RLONI, NI, NF, IWK, RWK, NC, RLATO, RLONO, RC, NCA, NUMV, NV, IER) DescriptionNPTS (integer,input) The number of input data points (NPTS > 3). RLATI (real, input) An array containing the latitudes of the input data, expressed in degrees. The first…
CSSTRID – calculates a Delaunay triangulation for data on a sphere SynopsisCALL CSSTRID (N, RLAT, RLON, NT, NTRI, IWK, RWK, IER) DescriptionN (integer,input) The number of input data points (N > 2). RLAT (double precision, input) An array containing the latitudes of the input data, expressed in degrees. The first three points must not be…
CSSTRI – calculates a Delaunay triangulation for data on a sphere SynopsisCALL CSSTRI (N, RLAT, RLON, NT, NTRI, IWK, RWK, IER) DescriptionN (integer,input) The number of input data points (N > 2). RLAT (real, input) An array containing the latitudes of the input data, expressed in degrees. The first three points must not be collinear…
CSSGRIDD – tension spline interpolation on a sphere. SynopsisCALL CSSGRIDD (N, RLAT, RLON, F, NI, NJ, PLAT, PLON, FF, IWK, RWK, IER) DescriptionN (integer,input) The number of input data points (N > 2). RLAT (double precision, input) An array containing the latitudes of the input data, expressed in degrees. The first three points must not…
cssgrid_params – This document briefly describes all the internal parameters of Cssgrid. DescriptionEach entry below includes the name of a parameter, its Fortran type (use the obvious equivalents for C), its default value, and a short description of the parameter. ‘SIG’ – Real – computed value of the tension factor for the splines ‘TOL’ –…
cssgrid_errors – This document briefly describes all the errors reported from Cssgrid. DescriptionEach entry below includes the error number and its meaning. 1 Invalid number of input points (must be greater than 3). 2 Invalid dimension for latitudes in the output grid. 3 Invalid dimension for longitudes in the output grid. 4 First three nodes…
CSSGRID – tension spline interpolation on a sphere. SynopsisCALL CSSGRID (N, RLAT, RLON, F, NI, NJ, PLAT, PLON, FF, IWK, RWK, IER) DescriptionN (integer,input) The number of input data points (N > 2). RLAT (real, input) An array containing the latitudes of the input data, expressed in degrees. The first three points must not be…
CSSETR – Sets the value of an internal parameter of type REAL for the Cssgrid package. SynopsisCALL CSSETR (PNAM,RVAL) DescriptionPNAM A character string that specifies the name of the parameter to be set. RVAL A REAL value that is the value to be assigned to the internal parameter specified by PNAM.UsageThis routine allows you to…
CSSETI – Sets the value of an internal parameter of type INTEGER. SynopsisCALL CSSETI (PNAM,IVAL) DescriptionPNAM A character string that specifies the name of the parameter to be set. IVAL An INTEGER value that is the value to be assigned to the internal parameter specified by PNAM.UsageThis routine allows you to set the current value…
CSSETD – Sets the value of an internal parameter of type DOUBLE PRECISION for the Cssgrid package. SynopsisCALL CSSETD (PNAM,DVAL) DescriptionPNAM A character string that specifies the name of the parameter to be set. DVAL A DOUBLE PRECISION value that is the value to be assigned to the internal parameter specified by PNAM.UsageThis routine allows…
Cssgrid is a software package in the ngmath library that implements a tension spline interpolation algorithm to fit a function to input data randomly located on the surface of a sphere. There are user-settable parameters that control various aspects of the algorithm, the most important of which is the tension factor that controls the level…