ref: 1f8d347c92a948bafde638c4864bc46096058dd3
parent: 40f6e00b9c4b0f5bdca1cc7caf27af23a6b10786
author: aiju <devnull@localhost>
date: Sun May 20 05:14:16 EDT 2018
fplot: draw axes; zoom more naturally; unzoom
--- a/sys/man/1/fplot
+++ b/sys/man/1/fplot
@@ -27,6 +27,11 @@
.B -r
option accepts as argument the x and y ranges, in the format
.LR "xmin:xmax ymin:ymax".
+By default
+.I fplot
+draws coordinate axes and tick marks; the
+.B -a
+option inhibits this.
.PP
Each function to be plotted may be a combination of the independent variable x,
the elementary operations (+, -, *, / and %), and the functions described in
@@ -55,9 +60,11 @@
.LR "syntax error"
or an empty status.
.SH BUGS
-Parentheses after unary operators are not special, e.g. sin(x)/2 is parsed as sin x/2 = sin(x/2) and not (sin x)/2.
-.PP
There is no unary plus or minus.
+.PP
+Axes are not drawn in
+.B -c
+output.
.SH HISTORY
.I Fplot
first appeared in 9front (July, 2011).
--- a/sys/src/cmd/fplot.c
+++ b/sys/src/cmd/fplot.c
@@ -75,16 +75,16 @@
"/", OBINARY, 0, 100, div,
"%", OBINARY, 0, 100, mod,
"^", OBINARY, 1, 200, pot,
- "sin", OUNARY, 0, 50, osin,
- "cos", OUNARY, 0, 50, ocos,
- "tan", OUNARY, 0, 50, otan,
- "asin", OUNARY, 0, 50, oasin,
- "acos", OUNARY, 0, 50, oacos,
- "atan", OUNARY, 0, 50, oatan,
- "sqrt", OUNARY, 0, 50, osqrt,
- "exp", OUNARY, 0, 50, oexp,
- "log", OUNARY, 0, 50, olog,
- "ln", OUNARY, 0, 50, oln,
+ "sin", OUNARY, 0, 300, osin,
+ "cos", OUNARY, 0, 300, ocos,
+ "tan", OUNARY, 0, 300, otan,
+ "asin", OUNARY, 0, 300, oasin,
+ "acos", OUNARY, 0, 300, oacos,
+ "atan", OUNARY, 0, 300, oatan,
+ "sqrt", OUNARY, 0, 300, osqrt,
+ "exp", OUNARY, 0, 300, oexp,
+ "log", OUNARY, 0, 300, olog,
+ "ln", OUNARY, 0, 300, oln,
};
struct Constant {@@ -105,11 +105,18 @@
Token *opstackbot;
double xmin = -10, xmax = 10;
double ymin = -10, ymax = 10;
+double gymin, gymax;
Image *color;
-int cflag;
+int cflag, aflag;
char *imagedata;
int picx = 640, picy = 480;
+typedef struct FRectangle FRectangle;
+struct FRectangle {+ double xmin, xmax, ymin, ymax;
+} *zoomst;
+int nzoomst;
+
void *
emalloc(int size)
{@@ -321,6 +328,8 @@
case OUNARY: case OBINARY:
o->f();
}
+ if(*sp < gymin) gymin = *sp;
+ if(*sp > gymax) gymax = *sp;
return *sp;
}
@@ -401,11 +410,158 @@
{int x;
+ gymin = Inf(1);
+ gymax = Inf(-1);
for(x = r->min.x; x < r->max.x; x++)
drawinter(co, r, convx(r, x), convx(r, x + 1), 0);
}
void
+tickfmt(double d, double m, int n, char *fmt)
+{+ double e1, e2;
+ int x;
+
+ e1 = log10(fabs(m));
+ e2 = log10(fabs(m + n * d));
+ if(e2 > e1) e1 = e2;
+ if(e2 >= 4 || e2 < -3){+ x = ceil(e1-log10(d)-1);
+ snprint(fmt, 32, "%%.%de", x);
+ }else{+ x = ceil(-log10(d));
+ snprint(fmt, 32, "%%.%df", x);
+ }
+}
+
+int
+xticklabel(char *fmt, double g, int p, int x, int y)
+{+ char buf[32];
+ Rectangle lr;
+ int ny;
+
+ snprint(buf, sizeof(buf), fmt, g);
+ lr.min = Pt(p, y+2);
+ lr.max = addpt(lr.min, stringsize(display->defaultfont, buf));
+ lr = rectsubpt(lr, Pt(Dx(lr) / 2-1, 0));
+ if(lr.max.y >= screen->r.max.y){+ ny = y - 7 - Dy(lr);
+ lr = rectsubpt(lr, Pt(0, lr.min.y - ny));
+ }
+ if(rectinrect(lr, screen->r) && (lr.min.x > x || lr.max.x <= x)){+ string(screen, lr.min, display->black, ZP, display->defaultfont, buf);
+ return 1;
+ }
+ return 0;
+}
+
+int
+yticklabel(char *fmt, double g, int p, int x, int y)
+{+ char buf[32];
+ Rectangle lr;
+ int nx;
+
+ snprint(buf, sizeof(buf), fmt, g);
+ lr.min = Pt(0, 0);
+ lr.max = stringsize(display->defaultfont, buf);
+ lr = rectaddpt(lr, Pt(x-Dx(lr)-2, p - Dy(lr) / 2));
+ if(lr.min.x < screen->r.min.x){+ nx = x + 7;
+ lr = rectsubpt(lr, Pt(lr.min.x - nx, 0));
+ }
+ if(rectinrect(lr, screen->r) && (lr.min.y > y || lr.max.y <= y)){+ string(screen, lr.min, display->black, ZP, display->defaultfont, buf);
+ return 1;
+ }
+ return 0;
+}
+
+int
+calcm(double min, double max, int e, double *dp, double *mp)
+{+ double d, m, r;
+
+ d = pow(10, e>>1);
+ if((e & 1) != 0) d *= 5;
+ m = min;
+ if(min < 0 && max > 0)
+ m += fmod(-m, d);
+ else{+ r = fmod(m, d);
+ if(r < 0)
+ m -= r;
+ else
+ m += d - r;
+ }
+ if(dp != nil) *dp = d;
+ if(mp != nil) *mp = m;
+ return (max-m)*0.999/d;
+}
+
+int
+ticks(double min, double max, double *dp, double *mp)
+{+ int e, n;
+ double m;
+ int beste;
+ double bestm;
+
+ e = 2 * ceil(log10(max - min));
+ beste = 0;
+ bestm = Inf(1);
+ for(;e>-100;e--){+ n = calcm(min, max, e, nil, nil);
+ if(n <= 0) continue;
+ if(n < 10) m = 10.0 / n;
+ else m = n / 10.0;
+ if(m < bestm){+ beste = e;
+ bestm = m;
+ }
+ if(n > 10) break;
+ }
+ calcm(min, max, beste, dp, mp);
+ return (max - *mp) / *dp;
+}
+
+void
+drawaxes(void)
+{+ int x, y, p;
+ double dx, dy, mx, my;
+ int nx, ny;
+ int i;
+ char fmt[32];
+
+ if(xmin < 0 && xmax > 0)
+ x = deconvx(&screen->r, 0);
+ else
+ x = screen->r.min.x+5;
+ line(screen, Pt(x, screen->r.min.y), Pt(x, screen->r.max.y), Endarrow, 0, 0, display->black, ZP);
+ if(ymin < 0 && ymax > 0)
+ y = deconvy(&screen->r, 0);
+ else
+ y = screen->r.max.y-5;
+ line(screen, Pt(screen->r.min.x, y), Pt(screen->r.max.x, y), 0, Endarrow, 0, display->black, ZP);
+ nx = ticks(xmin, xmax, &dx, &mx);
+ tickfmt(dx, mx, nx, fmt);
+ for(i = 0; i <= nx; i++){+ p = deconvx(&screen->r, dx*i+mx);
+ if(xticklabel(fmt, dx*i+mx, p, x, y))
+ line(screen, Pt(p, y), Pt(p, y-5), 0, 0, 0, display->black, ZP);
+ }
+ ny = ticks(ymin, ymax, &dy, &my);
+ tickfmt(dy, my, ny, fmt);
+ for(i = 0; i <= ny; i++){+ p = deconvy(&screen->r, dy*i+my);
+ if(yticklabel(fmt, dy*i+my, p, x, y))
+ line(screen, Pt(x, p), Pt(x+5, p), 0, 0, 0, display->black, ZP);
+ }
+}
+
+void
drawgraphs(void)
{int i;
@@ -413,6 +569,8 @@
color = display->black;
for(i = 0; i < nfns; i++)
drawgraph(&fns[i], &screen->r);
+ if(!aflag)
+ drawaxes();
flushimage(display, 1);
}
@@ -419,7 +577,7 @@
void
usage(void)
{- fprint(2, "usage: fplot [-c [-s size]] [-r range] functions ...\n");
+ fprint(2, "usage: fplot [-a] [-c [-s size]] [-r range] functions ...\n");
exits("usage");}
@@ -430,10 +588,13 @@
Rectangle r;
double xmin_, xmax_, ymin_, ymax_;
- m.buttons = 7;
+ m.buttons = 0;
r = egetrect(1, &m);
if(Dx(r) < 1 || Dy(r) < 1)
return;
+ zoomst = realloc(zoomst, sizeof(FRectangle) * (nzoomst + 1));
+ if(zoomst == nil) sysfatal("realloc: %r");+ zoomst[nzoomst++] = (FRectangle){xmin, xmax, ymin, ymax};xmin_ = convx(&screen->r, r.min.x);
xmax_ = convx(&screen->r, r.max.x);
ymin_ = convy(&screen->r, r.max.y);
@@ -447,6 +608,20 @@
}
void
+unzoom(void)
+{+ if(nzoomst == 0) return;
+ xmin = zoomst[nzoomst - 1].xmin;
+ xmax = zoomst[nzoomst - 1].xmax;
+ ymin = zoomst[nzoomst - 1].ymin;
+ ymax = zoomst[nzoomst - 1].ymax;
+ zoomst = realloc(zoomst, sizeof(FRectangle) * --nzoomst);
+ if(zoomst == nil && nzoomst != 0) sysfatal("realloc: %r");+ draw(screen, screen->r, display->white, nil, ZP);
+ drawgraphs();
+}
+
+void
parsefns(int n, char **s)
{int i, max, cur;
@@ -497,8 +672,10 @@
Event e;
Rectangle r;
int i;
+ static int lbut;
ARGBEGIN {+ case 'a': aflag++; break;
case 'r': parserange(EARGF(usage())); break;
case 's': parsesize(EARGF(usage())); break;
case 'c': cflag++; break;
@@ -526,10 +703,27 @@
drawgraphs();
for(;;) { switch(event(&e)) {+ case Emouse:
+ if((e.mouse.buttons & 1) != 0)
+ zoom();
+ if((~e.mouse.buttons & lbut & 4) != 0)
+ unzoom();
+ lbut = e.mouse.buttons;
+ break;
case Ekeyboard:
switch(e.kbdc) {- case 'q': exits(nil);
- case 'z': zoom();
+ case 'q': case 127: exits(nil); break;
+ case 'y':
+ if(!isInf(ymin, 1) && !isInf(ymax, -1)){+ zoomst = realloc(zoomst, sizeof(FRectangle) * (nzoomst + 1));
+ if(zoomst == nil) sysfatal("realloc: %r");+ zoomst[nzoomst++] = (FRectangle){xmin, xmax, ymin, ymax};+ ymin = gymin-0.05*(gymax-gymin);
+ ymax = gymax+0.05*(gymax-gymin);
+ draw(screen, screen->r, display->white, nil, ZP);
+ drawgraphs();
+ }
+ break;
}
}
}