GEOSTATS: Summary of Boostrapping Replies
- Hello. A summary of the replies I received to the following request is
provided below. I have decided to go with Mathematica after
discovering the huge discount for students. It is capable of generating
voronoi diagrams as well as performing the resampling (and many other
things of course).
I have not looked into the reply regarding placing constraints on
resampling (reply #11) although intend to. I am curious if anyone else
has feedback on this subject.
Thanks to all those who responded.
I am working on a m.s. thesis that involves the use of
parametric and non-parametric methods of estimating average
concentrations of lead. My questions are:
1) Does anybody have or know of software (preferably shareware) that
performs bootstrapping (or some other resampling method)? I am aware of
Mathematica but it is not within my budget.
2) I am also looking for software that can calculate theissen polygons
(aka: voronoi diagrams and polygons of influence).
Any help will be appreciated,
1) Check out the " Software for bootstrap computations" appendix in "An
Introduction to the Bootstrap" Monograph on Statistics and Applied
Probability 57; Efron, Bradley and Robert J. Tibshirani. Chapman & Hall,
1993. It mentions an MS-DOS package called "Resampling stats. Obtained
from: Resampling Stats
612 N. Jackson St. Arlington, VA 22201
2) S or S-plus has built-in facilities for vectors, matrices, etc. S
language functions are given in the above appendix.
3) Are you aware of the cross-validation capabilities of kt3d in the
GSLIB package? It will reestimate (kriging) each sample point in the
data set using all the other points. You might also be interested in
Direct Assessment of Local Accuracy and Precision, by Clayton Deutsch
presented at the 1996 Geostats Congress in Wollongong.
4) I just bought Mathematica for a decent price. As a student, you can
get Mathematica 3.0 (the latest version) for $ 139.95. The phone number
is 1-800-441-MATH. Although you can order it by phone, you will be
asked to mail or fax a copy of your student ID. If I remember
correctly, this price was not on the Wolfram/Mathematica Home-page, but
it was on a brochure that I received. The only disadvantage of the
student version is that you do not get the manuals in hard copy, but on
5) RESAMPLE is on the SU clusters server.
6) I would recommend Matlab. It too may not be within your budget, but
I would check student prices and availability at your school. There is
a lot of code available and it is a superlative number cruncher. As a
non-mathematician and non-programmer, I have found it very intuitive and
easy to modify to my needs.
7) If you have access to your university software then there is a good
chance that they have IMSL. IMSL is a collection of Fortran subroutines
for problem solving and statistical development.
8) If you get a general purpose program like IDL you can easily write a
simple program to do resampling and many other things. I think that
they have a student version available.
9) Techbase software has an academic loan program with minimal costs
involved to set it up
10) You could write your own program. "Numerical Recipes" by Press et
al. is a good source of random number generators.
11) Bootstrap has to be constrained by some statistical properties as
revealed from the data available (variogram, pdf, ....etc). To do so you
have to find a way by which you can generate a random field that
reproduce similar statistics as estimated from the data. See: Lall and
Sharma, WRR 32(3), 679-690, 1996.
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