Programming and Graphics

7.5 A graph with axes 223

,char labely[] // y-axis label

,char title1[] // first plot title

,char title2[] // second plot title

,char title3[] // third plot title

)

{

//--- Prepare:

float xrange = xmax-xmin;

float yrange = ymax-ymin;

float xmargin = 0.1*xrange;

float ymargin = 0.1*yrange;

float rticx = xrange/ntcx; // x tick distance

float rticy = yrange/ntcy; // y tick distance

float tchx = 0.1*xmargin; // x tick height

float tchy = 0.1*ymargin ; // y tick height

//--- Draw x and y axes:

color (axc);

move2 (xmin,ymin);

draw2 (xmax,ymin);

move2 (xmin,ymin);

draw2 (xmin,ymax);

//--- Print axes labels at the end of the axes:

move2 (xmax+0.5*rticx, ymin-0.1*ymargin);

drawstr (labelx);

move2 (xmin-0.8*xmargin, ymax+0.3*ymargin);

drawstr (labely);

/*----------------------------

Prepare to draw axes ticks

Generate tick labels

Print them in file "xyunit"

Read them as characters into arrays: xunit, yunit

---------------------------------*/

if(Ilabelax==1)

{

ofstream file1;

file1.open("xyunit");