teragen.c

很经典的电磁计算（电容计算）软件 MIT90年代开发

/*
Copyright (c) 1990 Massachusetts Institute of Technology, Cambridge, MA.
All rights reserved.

This Agreement gives you, the LICENSEE, certain rights and obligations.
By using the software, you indicate that you have read, understood, and
will comply with the terms.

Permission to use, copy and modify for internal, noncommercial purposes
is hereby granted.  Any distribution of this program or any part thereof
is strictly prohibited without prior written consent of M.I.T.

Title to copyright to this software and to any associated documentation
shall at all times remain with M.I.T. and LICENSEE agrees to preserve
same.  LICENSEE agrees not to make any copies except for LICENSEE'S
internal noncommercial use, or to use separately any portion of this
software without prior written consent of M.I.T.  LICENSEE agrees to
place the appropriate copyright notice on any such copies.

Nothing in this Agreement shall be construed as conferring rights to use
in advertising, publicity or otherwise any trademark or the name of
"Massachusetts Institute of Technology" or "M.I.T."

M.I.T. MAKES NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED.  By
way of example, but not limitation, M.I.T. MAKES NO REPRESENTATIONS OR
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE OR
THAT THE USE OF THE LICENSED SOFTWARE COMPONENTS OR DOCUMENTATION WILL
NOT INFRINGE ANY PATENTS, COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS.
M.I.T. shall not be held liable for any liability nor for any direct,
indirect or consequential damages with respect to any claim by LICENSEE
or any third party on account of or arising from this Agreement or use
of this software.
*/

#include <stdio.h>
#include <math.h>

#define DEFSID 1.0		/* default side and height, meters */
#define DEFEFR 0.1		/* default edge-cell-width/inner-cell-width */
#define DEFNCL 3		/* default #cells on short side of faces */

#define DEBUG 0

#define X0 0.0
#define Y0 0.0
#define Z0 0.0
#define XH 1.0
#define YH 1.0
#define ZH 1.0

#define TRUE 1
#define FALSE 0

#define MIN(A,B)  ( (A) > (B) ? (B) : (A) )

/*
  generates a pyramid example in quickif.c format
  - uses disRect() and discTri() for discretization of plates
*/
int
main(argc, argv)
int argc;
char *argv[];
{
  char temp[BUFSIZ], name[BUFSIZ], **chkp, *chk;
  int npanels = 0, ncells, cmderr = FALSE, i, cond, center_on_origin, no_top;
  int top_area, right_side_area, left_side_area, no_perimeter, no_discr;
  int right_cells, left_cells, top_cells, no_bottom, top_cells_given;
  int no_perimeter_front_left, no_perimeter_front_right;
  int no_perimeter_back_left, no_perimeter_back_right, name_given;
  double edgefrac, width, strtod(), pos_end, neg_end;
  double x1, y1, z1, x2, y2, z2, x3, y3, z3, x0, y0, z0; /* 4 corners */
  double xh, yh, zh, x4, y4, z4;
  long strtol();
  FILE *fp, *fopen();

  /* load default parameters */
  width = DEFSID;
  edgefrac = DEFEFR;
  ncells = DEFNCL;
  center_on_origin = no_top = no_perimeter = no_bottom = no_discr = FALSE;
  top_cells_given = FALSE;
  x0 = X0; y0 = Y0; z0 = Z0;
  xh = XH; yh = YH; zh = ZH;
  no_perimeter_front_left = no_perimeter_front_right = FALSE;
  no_perimeter_back_left = no_perimeter_back_right = FALSE;
  name_given = FALSE;

  /* parse command line */
  chkp = &chk;			/* pointers for error checking */
  for(i = 1; i < argc && cmderr == FALSE; i++) {
    if(argv[i][0] != '-') {
      fprintf(stderr, "%s: illegal argument -- %s\n", argv[0], argv[i]);
      cmderr = TRUE;
      break;
    }
    else if(argv[i][1] == 'n' && argv[i][2] == 'a') {
      if(sscanf(&(argv[i][3]), "%s", name) != 1) {
	fprintf(stderr, "%s: bad name `%s'\n", argv[0], &argv[i][3]);
	cmderr = TRUE;
	break;
      }
      name_given = TRUE;
    }
    else if(argv[i][1] == 'n') {
      ncells = (int) strtol(&(argv[i][2]), chkp, 10);
      if(*chkp == &(argv[i][2]) || ncells < 1) {
	fprintf(stderr, 
		"%s: bad number of panels/side `%s'\n", 
		argv[0], &argv[i][2]);
	cmderr = TRUE;
	break;
      }
    }
    else if(argv[i][1] == 'e') {
      edgefrac = strtod(&(argv[i][2]), chkp);
      if(*chkp == &(argv[i][2]) || edgefrac < 0.0) {
	fprintf(stderr, "%s: bad edge panel fraction `%s'\n", 
		argv[0], &argv[i][2]);
	cmderr = TRUE;
	break;
      }
    }
    else if(argv[i][1] == 'x' && argv[i][2] == 'o') {
      x0 = strtod(&(argv[i][3]), chkp);
      if(*chkp == &(argv[i][3])) {
	fprintf(stderr, "%s: bad x origin value `%s'\n", 
		argv[0], &argv[i][3]);
	cmderr = TRUE;
	break;
      }
    }
    else if(argv[i][1] == 'y' && argv[i][2] == 'o') {
      y0 = strtod(&(argv[i][3]), chkp);
      if(*chkp == &(argv[i][3])) {
	fprintf(stderr, "%s: bad y origin value `%s'\n", 
		argv[0], &argv[i][3]);
	cmderr = TRUE;
	break;
      }
    }
    else if(argv[i][1] == 'z' && argv[i][2] == 'o') {
      z0 = strtod(&(argv[i][3]), chkp);
      if(*chkp == &(argv[i][3])) {
	fprintf(stderr, "%s: bad z origin value `%s'\n", 
		argv[0], &argv[i][3]);
	cmderr = TRUE;
	break;
      }
    }
    else if(argv[i][1] == 'x' && argv[i][2] == 'h') {
      xh = strtod(&(argv[i][3]), chkp);
      if(*chkp == &(argv[i][3])) {
	fprintf(stderr, "%s: bad x height value `%s'\n", 
		argv[0], &argv[i][3]);
	cmderr = TRUE;
	break;
      }
    }
    else if(argv[i][1] == 'y' && argv[i][2] == 'h') {
      yh = strtod(&(argv[i][3]), chkp);
      if(*chkp == &(argv[i][3])) {
	fprintf(stderr, "%s: bad y height value `%s'\n", 
		argv[0], &argv[i][3]);
	cmderr = TRUE;
	break;
      }
    }
    else if(argv[i][1] == 'z' && argv[i][2] == 'h') {
      zh = strtod(&(argv[i][3]), chkp);
      if(*chkp == &(argv[i][3])) {
	fprintf(stderr, "%s: bad z height value `%s'\n", 
		argv[0], &argv[i][3]);
	cmderr = TRUE;
	break;
      }
    }
    else if(!strcmp(&(argv[i][1]), "pfl")) {
      no_perimeter_front_left = TRUE;
    }
    else if(!strcmp(&(argv[i][1]), "pfr")) {
      no_perimeter_front_right = TRUE;
    }
    else if(!strcmp(&(argv[i][1]), "pbl")) {
      no_perimeter_back_left = TRUE;
    }
    else if(!strcmp(&(argv[i][1]), "pbr")) {
      no_perimeter_back_right = TRUE;
    }
    else if(!strcmp(&(argv[i][i]), "p")
) {
      no_perimeter = TRUE;
    }
    else if(argv[i][1] == 'b') {
      no_bottom = TRUE;
    }
    else if(argv[i][1] == 'd') {
      no_discr = TRUE;
    }
    else {
      fprintf(stderr, "%s: illegal option -- %s\n", argv[0], &(argv[i][1]));
      cmderr = TRUE;
      break;
    }
  }

  if(cmderr == TRUE) {
    fprintf(stderr,
	    "Usage: %s [-xo<originx>] [-yo<originy>] [-zo<originz>] \n               [-xh<heightx>] [-yh<heighty>] [-zh<heightz>] \n               [-n<num panels/side>] [-e<rel edge panel width>] \n               [-na<name>] [-b] [-p] [-pfl] [-pfr] [-pbl] [-pbr] [-d]\n", 
	    argv[0]);
    fprintf(stdout, "DEFAULT VALUES:\n");
    fprintf(stderr, "  origin = (xo yo zo) = (%g %g %g)\n", X0, Y0, Z0);
    fprintf(stderr, "  side heights = (xh yh zh) = (%g %g %g)\n", XH, YH, ZH);
    fprintf(stdout, "  num panels/side = %d\n", DEFNCL);
    fprintf(stdout, "  rel edge panel width = %g\n", DEFEFR);
    fprintf(stdout, "  conductor name = `1'\n");
    fprintf(stdout, "OPTIONS:\n");
    fprintf(stdout, "  -b don't include bottom (rectangular) face\n");
    fprintf(stdout, "  -p don't include any perimeter (side) faces\n");
    fprintf(stdout, "  -pfl don't include perimeter front left face (view from positive orthant)\n");
    fprintf(stdout, "  -pfr don't include perimeter front right face\n");
    fprintf(stdout, "  -pbl don't include perimeter back left face\n");
    fprintf(stdout, "  -pbr don't include perimeter back right face\n");
    fprintf(stdout, "  -d don't discretize faces\n");
    return (1);
  }

  /* open output file */
  fp = stdout;

  /* write title */
  if(center_on_origin) {
    fprintf(fp, 
	    "0 %gmX%gmX%gm pyramid centered on origin (n=%d e=%.3g)\n",
	    xh, yh, zh, ncells, edgefrac);
    x0 = -xh/2.0; y0 = -yh/2.0; z0 = -zh/2.0;
  }
  else {
    fprintf(fp, 
	    "0 %gmX%gmX%gm pyramid (n=%d e=%.3g)\n",
	    xh, yh, zh, ncells, edgefrac);
    fprintf(fp, "* xo = %g, yo = %g, zo = %g\n", x0, y0, z0);
  }
  if(no_bottom) fprintf(fp, "* bottom panel omitted\n");
  if(no_perimeter) fprintf(fp, "* all side panels omitted\n");
  else {
    if(no_perimeter_front_left)
	fprintf(fp, "* front left side panel omitted\n");
    if(no_perimeter_front_right)
	fprintf(fp, "* front right side panel omitted\n");
    if(no_perimeter_back_left)
	fprintf(fp, "* back left side panel omitted\n");
    if(no_perimeter_back_right)
	fprintf(fp, "* back right side panel omitted\n");
  }

  /* set up corners */
  x1 = x0 + xh; y1 = y0; z1 = z0;
  x2 = x0; y2 = y0 + yh; z2 = z0;
  x3 = x0 + xh; y3 = y0 + yh; z3 = z0;
  x4 = x0 + xh/2.0; y4 = y0 + yh/2.0; z4 = z0 + zh;

  left_cells = right_cells = ncells; /* in case want to set one rel to other */
  top_cells = ncells;

  /* write panels with outward pointing normals */
  fprintf(stdout, "* view from -x, -y, +z\n");

  if(!no_perimeter) {
    if(!no_perimeter_front_right) {
      fprintf(stdout, "* front right\n");
      npanels += disTri(fp, 1, edgefrac, right_cells, no_discr,
			x3, y3, z3,
			x4, y4, z4,
			x2, y2, z2);
    }
#if DEBUG == 0
    if(!no_perimeter_front_left) {
      fprintf(stdout, "* front left\n");
      npanels += disTri(fp, 1, edgefrac, left_cells, no_discr,
			x1, y1, z1,
			x4, y4, z4,
			x3, y3, z3);
    }

    if(!no_perimeter_back_left) {
      fprintf(stdout, "* back left\n");
#if DEBUG == 1
      npanels += disTri(fp, 1, edgefrac, right_cells, no_discr,
			x0, y0, z0,
			x2, y2, z2,
			x1, y1, z1);
#else
      npanels += disTri(fp, 1, edgefrac, right_cells, no_discr,
			x0, y0, z0,
			x4, y4, z4,
			x1, y1, z1);
#endif
    }

    if(!no_perimeter_back_right) {
      fprintf(stdout, "* back right\n");
      npanels += disTri(fp, 1, edgefrac, left_cells, no_discr,
			x2, y2, z2,
			x4, y4, z4,
			x0, y0, z0);
    }
#endif
  }

  if(!no_bottom) {
    fprintf(stdout, "* bottom\n");
    npanels += disRect(fp, 1, edgefrac, top_cells, no_discr,
		       x0, y0, z0,
		       x2, y2, z2,
		       x3, y3, z3,
		       x1, y1, z1);
  }

  if(name_given) fprintf(fp, "N 1 %s\n", name);

  return (0);
}