Date: 2013-07-02T14:38:19+00:00

Actual source code: dtri.c
petsc-3.4.2 2013-07-02

      2: /*
      3:        Provides the calling sequences for all the basic PetscDraw routines.
      4: */
      5: #include <petsc-private/drawimpl.h>  /*I "petscdraw.h" I*/

      9: /*@
     10:    PetscDrawTriangle - PetscDraws a triangle  onto a drawable.

     12:    Not Collective

     14:    Input Parameters:
     15: +  draw - the drawing context
     16: .  x1,y1,x2,y2,x3,y3 - the coordinates of the vertices
     17: -  c1,c2,c3 - the colors of the three vertices in the same order as the xi,yi

     19:    Level: beginner

     21:    Concepts: drawing^triangle
     22:    Concepts: graphics^triangle
     23:    Concepts: triangle

     25: @*/
     26: PetscErrorCode  PetscDrawTriangle(PetscDraw draw,PetscReal x1,PetscReal y_1,PetscReal x2,PetscReal y2,PetscReal x3,PetscReal y3,int c1,int c2,int c3)
     27: {
     29:   PetscBool      isnull;

     33:   PetscObjectTypeCompare((PetscObject)draw,PETSC_DRAW_NULL,&isnull);
     34:   if (isnull) return(0);
     35:   (*draw->ops->triangle)(draw,x1,y_1,x2,y2,x3,y3,c1,c2,c3);
     36:   return(0);
     37: }

     42: /*@
     43:        PetscDrawScalePopup - PetscDraws a contour scale window.

     45:      Collective on PetscDraw

     47:   Input Parameters:
     48: +    popup - the window (often a window obtained via PetscDrawGetPopup()
     49: .    min - minimum value being plotted
     50: -    max - maximum value being plotted

     52:   Level: intermediate

     54:   Notes:
     55:      All processors that share the draw MUST call this routine

     57: @*/
     58: PetscErrorCode  PetscDrawScalePopup(PetscDraw popup,PetscReal min,PetscReal max)
     59: {
     60:   PetscReal      xl = 0.0,yl = 0.0,xr = 2.0,yr = 1.0,value;
     62:   int            i,c = PETSC_DRAW_BASIC_COLORS,rank;
     63:   char           string[32];
     64:   MPI_Comm       comm;

     67:   PetscDrawCheckResizedWindow(popup);
     68:   PetscObjectGetComm((PetscObject)popup,&comm);
     69:   MPI_Comm_rank(comm,&rank);
     70:   if (rank) return(0);

     72:   for (i=0; i<10; i++) {
     73:     PetscDrawRectangle(popup,xl,yl,xr,yr,c,c,c,c);

     75:     yl += .1; yr += .1;
     76:     c = (int)((double)c + (245. - PETSC_DRAW_BASIC_COLORS)/9.);
     77:   }
     78:   for (i=0; i<10; i++) {
     79:     value = min + i*(max-min)/9.0;
     80:     /* look for a value that should be zero, but is not due to round-off */
     81:     if (PetscAbsReal(value) < 1.e-10 && max-min > 1.e-6) value = 0.0;
     82:     sprintf(string,"%18.16e",(double)value);
     83:     PetscDrawString(popup,.2,.02 + i/10.0,PETSC_DRAW_BLACK,string);
     84:   }
     85:   PetscDrawSetTitle(popup,"Contour Scale");
     86:   PetscDrawFlush(popup);
     87:   return(0);
     88: }

     90: typedef struct {
     91:   int       m,n;
     92:   PetscReal *x,*y,min,max,*v;
     93:   PetscBool showgrid;
     94: } ZoomCtx;

     98: static PetscErrorCode PetscDrawTensorContour_Zoom(PetscDraw win,void *dctx)
     99: {
    101:   int            i;
    102:   ZoomCtx        *ctx = (ZoomCtx*)dctx;

    105:   PetscDrawTensorContourPatch(win,ctx->m,ctx->n,ctx->x,ctx->y,ctx->max,ctx->min,ctx->v);
    106:   if (ctx->showgrid) {
    107:     for (i=0; i<ctx->m; i++) {
    108:       PetscDrawLine(win,ctx->x[i],ctx->y[0],ctx->x[i],ctx->y[ctx->n-1],PETSC_DRAW_BLACK);
    109:     }
    110:     for (i=0; i<ctx->n; i++) {
    111:       PetscDrawLine(win,ctx->x[0],ctx->y[i],ctx->x[ctx->m-1],ctx->y[i],PETSC_DRAW_BLACK);
    112:     }
    113:   }
    114:   return(0);
    115: }

    119: /*@C
    120:    PetscDrawTensorContour - PetscDraws a contour plot for a two-dimensional array
    121:    that is stored as a PETSc vector.

    123:    Collective on PetscDraw, but PetscDraw must be sequential

    125:    Input Parameters:
    126: +   win   - the window to draw in
    127: .   m,n   - the global number of mesh points in the x and y directions
    128: .   xi,yi - the locations of the global mesh points (optional, use NULL
    129:             to indicate uniform spacing on [0,1])
    130: -   V     - the values

    132:    Options Database Keys:
    133: +  -draw_x_shared_colormap - Indicates use of private colormap
    134: -  -draw_contour_grid - PetscDraws grid contour

    136:    Level: intermediate

    138:    Concepts: contour plot
    139:    Concepts: drawing^contour plot

    141: .seealso: PetscDrawTensorContourPatch()

    143: @*/
    144: PetscErrorCode  PetscDrawTensorContour(PetscDraw win,int m,int n,const PetscReal xi[],const PetscReal yi[],PetscReal *v)
    145: {
    147:   int            N = m*n;
    148:   PetscBool      isnull;
    149:   PetscDraw      popup;
    150:   MPI_Comm       comm;
    151:   int            xin=1,yin=1,i;
    152:   PetscMPIInt    size;
    153:   PetscReal      h;
    154:   ZoomCtx        ctx;

    157:   PetscDrawIsNull(win,&isnull); if (isnull) return(0);
    158:   PetscObjectGetComm((PetscObject)win,&comm);
    159:   MPI_Comm_size(comm,&size);
    160:   if (size > 1) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"May only be used with single processor PetscDraw");
    161:   if (N <= 0) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"n %d and m %d must be positive",m,n);

    163:   /* create scale window */
    164:   PetscDrawGetPopup(win,&popup);
    165:   PetscDrawCheckResizedWindow(win);

    167:   ctx.v   = v;
    168:   ctx.m   = m;
    169:   ctx.n   = n;
    170:   ctx.max = ctx.min = v[0];
    171:   for (i=0; i<N; i++) {
    172:     if (ctx.max < ctx.v[i]) ctx.max = ctx.v[i];
    173:     if (ctx.min > ctx.v[i]) ctx.min = ctx.v[i];
    174:   }
    175:   if (ctx.max - ctx.min < 1.e-7) {ctx.min -= 5.e-8; ctx.max += 5.e-8;}

    177:   /* PetscDraw the scale window */
    178:   if (popup) {PetscDrawScalePopup(popup,ctx.min,ctx.max);}

    180:   ctx.showgrid = PETSC_FALSE;
    181:   PetscOptionsGetBool(NULL,"-draw_contour_grid",&ctx.showgrid,NULL);

    183:   /* fill up x and y coordinates */
    184:   if (!xi) {
    185:     xin      = 0;
    186:     PetscMalloc(ctx.m*sizeof(PetscReal),&ctx.x);
    187:     h        = 1.0/(ctx.m-1);
    188:     ctx.x[0] = 0.0;
    189:     for (i=1; i<ctx.m; i++) ctx.x[i] = ctx.x[i-1] + h;
    190:   } else ctx.x = (PetscReal*)xi;

    192:   if (!yi) {
    193:     yin      = 0;
    194:     PetscMalloc(ctx.n*sizeof(PetscReal),&ctx.y);
    195:     h        = 1.0/(ctx.n-1);
    196:     ctx.y[0] = 0.0;
    197:     for (i=1; i<ctx.n; i++) ctx.y[i] = ctx.y[i-1] + h;
    198:   } else ctx.y = (PetscReal*)yi;

    200:   PetscDrawZoom(win,(PetscErrorCode (*)(PetscDraw,void*))PetscDrawTensorContour_Zoom,&ctx);

    202:   if (!xin) {PetscFree(ctx.x);}
    203:   if (!yin) {PetscFree(ctx.y);}
    204:   return(0);
    205: }

    209: /*@
    210:    PetscDrawTensorContourPatch - PetscDraws a rectangular patch of a contour plot
    211:    for a two-dimensional array.

    213:    Not Collective

    215:    Input Parameters:
    216: +  win - the window to draw in
    217: .  m,n - the number of local mesh points in the x and y direction
    218: .  x,y - the locations of the local mesh points
    219: .  max,min - the maximum and minimum value in the entire contour
    220: -  v - the data

    222:    Options Database Keys:
    223: .  -draw_x_shared_colormap - Activates private colormap

    225:    Level: advanced

    227:    Note:
    228:    This is a lower level support routine, usually the user will call
    229:    PetscDrawTensorContour().

    231:    Concepts: contour plot

    233: .seealso: PetscDrawTensorContour()

    235: @*/
    236: PetscErrorCode  PetscDrawTensorContourPatch(PetscDraw draw,int m,int n,PetscReal *x,PetscReal *y,PetscReal max,PetscReal min,PetscReal *v)
    237: {
    239:   int            c1,c2,c3,c4,i,j;
    240:   PetscReal      x1,x2,x3,x4,y_1,y2,y3,y4,scale;

    243:   scale = (245.0 - PETSC_DRAW_BASIC_COLORS)/(max - min);

    245:   /* PetscDraw the contour plot patch */
    246:   for (j=0; j<n-1; j++) {
    247:     for (i=0; i<m-1; i++) {
    248:       x1 = x[i];  y_1 = y[j]; c1 = (int)(PETSC_DRAW_BASIC_COLORS + scale*(v[i+j*m] - min));
    249:       x2 = x[i+1];y2 = y_1;   c2 = (int)(PETSC_DRAW_BASIC_COLORS + scale*(v[i+j*m+1]-min));
    250:       x3 = x2;    y3 = y[j+1];c3 = (int)(PETSC_DRAW_BASIC_COLORS + scale*(v[i+j*m+1+m]-min));
    251:       x4 = x1;    y4 = y3;    c4 = (int)(PETSC_DRAW_BASIC_COLORS + scale*(v[i+j*m+m]-min));

    253:       PetscDrawTriangle(draw,x1,y_1,x2,y2,x3,y3,c1,c2,c3);
    254:       PetscDrawTriangle(draw,x1,y_1,x3,y3,x4,y4,c1,c3,c4);
    255:     }
    256:   }
    257:   return(0);
    258: }