Programming and Graphics

7.5 A graph with axes 229

int main()

{

float points[4][2];

//--- Define the data to be plotted:

...

//--- Define plotting parameters:

...

//--- Graphics:

float xmarg = 0.2*(xmax-xmin); // plotting margin

float ymarg = 0.2*(ymax-ymin);

int Icheck;

again:

prefposition (500,100);

prefsize (500,500);

vinit ("X11");

short Itry = 0;

short Iplot = 0;

repeat:

ortho2 (xmin-xmarg,xmax+xmarg,ymin-ymarg,ymax+ymarg);

color (YELLOW);

clear();

//--- Repaint the plotting area:

if(Iplot==4 || Iplot==6)

{

points[1][1] = xmin;

points[1][2] = ymin;

points[2][1] = xmax;

points[2][2] = ymin;

points[3][1] = xmax;

points[3][2] = ymax;

points[4][1] = xmin;

points[4][2] = ymax;

poly2 (4,points);

}

//--- draw markers