/* We want to be able to reconstruct x, |x|^2 < C, from x mod pr^k */
static double
bestlift_bound(GEN C, long d, double alpha, GEN Npr)
{
const double y = 1 / (alpha - 0.25); /* = 2 if alpha = 3/4 */
double t;
if (typ(C) != t_REAL) C = gmul(C, real_1(DEFAULTPREC));
setlg(C, DEFAULTPREC);
t = rtodbl(mplog(gmul2n(divrs(C,d), 4))) * 0.5 + (d-1) * log(1.5 * sqrt(y));
return ceil((t * d) / log(gtodouble(Npr)));
}
void
pariplot(GEN a, GEN b, GEN code, GEN ysmlu,GEN ybigu, long prec)
{
const char BLANK = ' ', YY = '|', XX_UPPER = '\'', XX_LOWER = '.';
long jz, j, i, sig;
pari_sp av = avma;
int jnew, jpre = 0; /* for lint */
GEN x, dx;
double diff, dyj, ysml, ybig, y[ISCR+1];
screen scr;
char buf[80], z;
sig=gcmp(b,a); if (!sig) return;
if (sig<0) { x=a; a=b; b=x; }
x = gtofp(a, prec); push_lex(x, code);
dx = divru(gtofp(gsub(b,a),prec), ISCR-1);
for (j=1; j<=JSCR; j++) scr[1][j]=scr[ISCR][j]=YY;
for (i=2; i<ISCR; i++)
{
scr[i][1] = XX_LOWER;
scr[i][JSCR]= XX_UPPER;
for (j=2; j<JSCR; j++) scr[i][j] = BLANK;
}
ysml = ybig = 0.; /* -Wall */
for (i=1; i<=ISCR; i++)
{
pari_sp av2 = avma;
y[i] = gtodouble( READ_EXPR(code,x) );
avma = av2;
if (i == 1)
ysml = ybig = y[1];
else
{
if (y[i] < ysml) ysml = y[i];
if (y[i] > ybig) ybig = y[i];
}
x = addrr(x,dx);
}
avma = av;
if (ysmlu) ysml = gtodouble(ysmlu);
if (ybigu) ybig = gtodouble(ybigu);
diff = ybig - ysml;
if (!diff) { ybig += 1; diff= 1.; }
dyj = ((JSCR-1)*3+2) / diff;
/* work around bug in gcc-4.8 (32bit): plot(x=-5,5,sin(x)))) */
jz = 3 - (long)(ysml*dyj + 0.5); /* 3 - DTOL(ysml*dyj) */
z = PICTZERO(jz); jz /= 3;
for (i=1; i<=ISCR; i++)
{
if (0<=jz && jz<=JSCR) scr[i][jz]=z;
j = 3 + DTOL((y[i]-ysml)*dyj);
jnew = j/3;
if (i > 1) fill_gap(scr, i, jnew, jpre);
if (0<=jnew && jnew<=JSCR) scr[i][jnew] = PICT(j);
jpre = jnew;
}
pari_putc('\n');
pari_printf("%s ", dsprintf9(ybig, buf));
for (i=1; i<=ISCR; i++) pari_putc(scr[i][JSCR]);
pari_putc('\n');
for (j=(JSCR-1); j>=2; j--)
{
pari_puts(" ");
for (i=1; i<=ISCR; i++) pari_putc(scr[i][j]);
pari_putc('\n');
}
pari_printf("%s ", dsprintf9(ysml, buf));
for (i=1; i<=ISCR; i++) pari_putc(scr[i][1]);
pari_putc('\n');
{
char line[10 + 32 + 32 + ISCR - 9];
sprintf(line, "%10s%-9.7g%*.7g\n"," ",todbl(a),ISCR-9,todbl(b));
pari_printf(line);
}
pop_lex(1);
}