Mercurial > octave-nkf

annotate scripts/finance/irr.m @ 3426:f8dde1807dee

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
[project @ 2000-01-13 08:40:00 by jwe]
author jwe
date Thu, 13 Jan 2000 08:40:53 +0000
parents e4f4b2d26ee9
children 3234a698073a
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
3191
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
1 ## Copyright (C) 1995, 1996, 1997 Kurt Hornik
3426
f8dde1807dee [project @ 2000-01-13 08:40:00 by jwe]
jwe
parents: 3191
diff changeset
2 ##
3191
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
3 ## This program is free software; you can redistribute it and/or modify
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
4 ## it under the terms of the GNU General Public License as published by
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
5 ## the Free Software Foundation; either version 2, or (at your option)
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
6 ## any later version.
3426
f8dde1807dee [project @ 2000-01-13 08:40:00 by jwe]
jwe
parents: 3191
diff changeset
7 ##
3191
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
8 ## This program is distributed in the hope that it will be useful, but
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
9 ## WITHOUT ANY WARRANTY; without even the implied warranty of
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
10 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
3426
f8dde1807dee [project @ 2000-01-13 08:40:00 by jwe]
jwe
parents: 3191
diff changeset
11 ## General Public License for more details.
f8dde1807dee [project @ 2000-01-13 08:40:00 by jwe]
jwe
parents: 3191
diff changeset
12 ##
3191
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
13 ## You should have received a copy of the GNU General Public License
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
14 ## along with this file. If not, write to the Free Software Foundation,
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
15 ## 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
16
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
17 ## usage: irr (p [, i])
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
18 ##
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
19 ## Computes the internal rate of return of a series of payments p from
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
20 ## an initial investment i, i.e., the solution of npv (r, p) = i. If the
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
21 ## second argument is omitted, i = 0 is used.
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
22 ##
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
23 ## See also: npv; pv, rate.
3426
f8dde1807dee [project @ 2000-01-13 08:40:00 by jwe]
jwe
parents: 3191
diff changeset
24
3191
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
25 ## Author: KH <Kurt.Hornik@ci.tuwien.ac.at>
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
26 ## Description: Internal rate of return of an investment
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
27
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
28 function r = irr (p, i)
3426
f8dde1807dee [project @ 2000-01-13 08:40:00 by jwe]
jwe
parents: 3191
diff changeset
29
3191
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
30 if (nargin == 1)
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
31 i = 0;
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
32 elseif !(nargin == 2)
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
33 usage ("irr (p [, i])");
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
34 endif
3426
f8dde1807dee [project @ 2000-01-13 08:40:00 by jwe]
jwe
parents: 3191
diff changeset
35
3191
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
36 tmp = output_precision;
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
37 output_precision = 15;
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
38 if !(is_vector (p))
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
39 error ("irr: p must be a vector");
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
40 else
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
41 p_string = type p;
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
42 endif
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
43
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
44 if !is_scalar (i)
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
45 error ("irr: i must be a scalar");
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
46 endif
3426
f8dde1807dee [project @ 2000-01-13 08:40:00 by jwe]
jwe
parents: 3191
diff changeset
47
3191
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
48 string = ["function delta = f (r) ", ...
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
49 "delta = npv (r, %s) - %g; end"];
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
50 eval (sprintf (string, p_string, i));
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
51
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
52 r = fsolve ("f", 0.01);
3426
f8dde1807dee [project @ 2000-01-13 08:40:00 by jwe]
jwe
parents: 3191
diff changeset
53
3191
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
54 output_precision = tmp;
3426
f8dde1807dee [project @ 2000-01-13 08:40:00 by jwe]
jwe
parents: 3191
diff changeset
55
3191
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
56 endfunction