```source("http://macosa.dima.unige.it/r.R")    # If I have not already loaded the library
---------- ---------- ---------- ---------- ---------- ---------- ---------- ----------
# We can also trace the direction field of the solutions of an indefinite integral.
# See here for explanations.

#
f1 = function(x) 1+x; f2 = function(x) 3^x; f3 = function(x) 1.5^x
f4 = function(x) 1/x; f5 = function(x) x^2; f6 = function(x) x
BF=1.8; HF=1.8
boxww(-3,2, -2,3); Dy = function(x,y) f1(x); diredif(-3,2,-2,3, 15,15)
GridHC(0,"blue"); GridVC(0,"blue");
underX("-3",-3); underX("2",2); underX("0",0); underY("-2",-2); underY("3",3); underY("0",0)
boxww(-3,2, -2,3); Dy = function(x,y) f2(x); diredif(-3,2,-2,3, 15,15)
GridHC(0,"blue"); GridVC(0,"blue");
underX("-3",-3); underX("2",2); underX("0",0); underY("-2",-2); underY("3",3); underY("0",0)
boxww(-3,2, -2,3); Dy = function(x,y) f3(x); diredif(-3,2,-2,3, 15,15)
GridHC(0,"blue"); GridVC(0,"blue");
underX("-3",-3); underX("2",2); underX("0",0); underY("-2",-2); underY("3",3); underY("0",0)
boxww(-3,2, -2,3); Dy = function(x,y) f4(x); diredif(-3,2,-2,3, 15,15)
GridHC(0,"blue"); GridVC(0,"blue");
underX("-3",-3); underX("2",2); underX("0",0); underY("-2",-2); underY("3",3); underY("0",0)
boxww(-3,2, -2,3); Dy = function(x,y) f5(x); diredif(-3,2,-2,3, 15,15)
GridHC(0,"blue"); GridVC(0,"blue");
underX("-3",-3); underX("2",2); underX("0",0); underY("-2",-2); underY("3",3); underY("0",0)
boxww(-3,2, -2,3); Dy = function(x,y) f6(x); diredif(-3,2,-2,3, 15,15)
GridHC(0,"blue"); GridVC(0,"blue");
underX("-3",-3); underX("2",2); underX("0",0); underY("-2",-2); underY("3",3); underY("0",0)

Other examples of use

```