1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
|
/* -*-ePiX-*- */
#include "epix.h"
using namespace ePiX;
double k(4); // change width of hump
double dx(0.05); // width of thin shaded region
double x(1/sqrt(k)); // position of thin shaded region
const double dy(0.5);
double f(double t)
{
return sqrt(fabs(k)/(2*M_PI))*exp(-k*t*t);
}
P pt1(x, f(x)+2*dy);
P pt2(x+dx,f(x)+dy);
P pt3(x+3*dx,f(x));
Color shade1(Black(0.1));
Color shade2(Black(0.4));
Color shade3(Black(0.6));
int main()
{
picture(P(0,0), P(1,1), "150x150pt");
begin();
legend L;
L.backing(Neutral());
fill(shade1);
shadeplot(f, xmin(), x, 90);
L.fill_item("$=\\displaystyle\\int_a^x f(t)\\,dt$");
fill(shade2);
rect(P(x,0), P(x+dx, f(x)));
L.fill_item("= $f(x)\\,dx\\vphantom{\\Bigg|}$");
fill(shade3);
shadeplot(f, x, x+dx, 10);
L.fill_item("= $F(x+dx)-F(x)$");
bold();
plot(f, xmin(), xmax(), 120);
plain();
h_axis(4);
v_axis(4);
font_size("scriptsize");
L.draw(canvas().tr(), P(-2,-2), bl);
font_size("footnotesize");
label(P(xmin(),0), P(0,-5), "$a$", b);
label(P(x,0), P(0,-5), "$x$", b);
label(P(x+dx,0), P(0,-2), "$x+dx$", br);
pst_format();
end();
}
|
