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Projection for 17th observation
Dear Marco,
This is the second response to your mail dated July 1st. Based on your mail, I
go back to the model and replaced C(15)=1120 with 895, thus the projection for
K=16 would be:
P(16)
A=485
B=245
C=812
D=1494
E=369
The complete output table follows.
Table of MDSM output for 15th observation and 16th projection.
k=15
P(15) D(15) E(15) IV(15) R(15) T(15) P(16)
A 597.5941 520 535.5188 0.292641 -62.0753 0.931759 484.5149
B 255.0158 234 238.2032 0.130169 -16.8127 1.046004 244.7648
C 1133.465 895 942.693 0.515146 -190.772 0.907379 812.1038
D 1408.263 1404 1404.853 0.767698 - 3.4104 1.063965 1493.807
E 410.2986 370 378.0597 0.206595 -32.2389 0.997123 368.9356
1964.292 1798.415 1829.954 1 203.9142 2.216283 1822.567
0.9955 0.9967
1.0012
Furthermore, I entered 16th observation, as D(16), based on your email, and the
MDSM projected P(17) for next observation which due the end of July:
P(17)
A=522
B=236
C=929
D=1448
E=330
The complete output Table follows.
Table of MDSM output for 16th observation and 17th projection.
k=16
P(16) D(16) E(16) IV(16) R(16) T(16) P(17)
A 484.5149 535 524.903 0.285692 40.38812 0.976256 522.2971
B 244.7648 237 238.553 0.129839 - 6.21186 0.997463 236.3988
C 812.1038 952 924.0208 0.502923 111.9169 0.976272 929.4113
D 1493.807 1422 1436.361 0.781777 -57.4459 1.018339 1448.079
E 368.9356 352 355.3871 0.193429 -13.5485 0.936269 329.5668
SGI 1822.567 1842.4671837.302 1 132.9616 2.19425 1843.375
0.9997 0.9974
0.9977
Let's see how close the projection will be this time.
P.S. You mentioned in your last mail that you were also collecting weekly-data.
Some times changing the time interval makes a better fit. Considering your data
are microorganisms, weekly data may describe the dynamics better.
Although a better projection would generally catch people' attention, I would
not expect this model to make a perfect projection. The purpose of this model
is only for supplying a formula or quantified mechanism that allow us to
monitor dynamics of communities. It is expected that this model would improve
and extend our understanding of the dynamics of multivariate communities.
P.P.S. After carefully read your mails, I understand that the 15th observation
was collected June 3rd, but posted June 19th. Ignore my question in previous
mail.
Thank you,
T. Jay BAI, Ph.D.
Quantitative Ecologist
970-490-8345
Bai@gpsr.colostate.edu
http://lamar.colostate.edu/~jbai