[R] Neural Network

javad bayat jbayat67 at yahoo.com
Sat Jan 24 07:41:09 CET 2015

Dear Charles;
I think my variables are dependent. For e.g. the concentration of  Phosphorus, Nitrogen, Silica and etc. have effect on the present of Chlorophyll a and the concentration of Chlorophyll a can make the Eutrophication in lake along with other algeas. 
So I think they are dependent variables.

On Thu, 1/22/15, Charles Determan Jr <deter088 at umn.edu> wrote:

 Subject: Re: [R] Neural Network

 Date: Thursday, January 22, 2015, 4:41 PM

 please make sure to hit 'reply all' so that these
 messages go to the R help list so others (many far more
 skilled than I) may possibly chime in.
 The problem here is that you appear
 to have no dependent variable (i.e. no eutrophication
 variable).  Without it, there is no way to a typical
 'supervised' analysis.  Given that this is likely a
 regression type problem (I assume eutrophication would be
 continous) I'm not quite sure 'supervised' is
 the correct description but it furthers my point that you
 need a dependent variable for any neuralnet algorithm I am
 aware of.  As such, if you don't have a dependent
 variable then you will need to look at unsupervised methods
 such as PCA.  Other users may have other
 On Wed, Jan 21, 2015 at


 Many thanks for your attention. what I want to know is: How
 can I predict the Eutrophication by these parameters in the

 These variables are the most important variables that
 control the Eutro. in lakes.

 Let me break it to two parts.

 1) How can I predict these variables by NN?

 2) Is it possible to predict the Eutro. by these

 Many thanks for your help.



 On Wed, 1/21/15, Charles Determan Jr <deter088 at umn.edu>

  Subject: Re: [R] Neural Network

  Cc: "r-help at r-project.org"
 <r-help at r-project.org>

  Date: Wednesday, January 21, 2015, 9:10 PM



  question is a little too broad to be answered

  definitively.  Also, this is not a code writing

  You should make a meaningful attempt and we are here to

  when you get stuck.


  If you want to know if you can do neural nets, the answer

  yes.  The three packages most commonly used (that I

  of) are 'neuralnet', 'nnet' and

  'RSNNS'.  You should look in to these package

  documentation for how to use them.  There are also

  examples online if you simply google them.

  2. You question is unclear, are you

  wanting to predict all the variables (e.g. phosphorus,

  N, etc.) or do you have some metric for

  What exactly is the model supposed to predict?

  3. If you want to know if a

  neuralnet is appropriate, that is more of a statistical

  question.  It depends more on the question you want to

  answer.  Given your temporal data, you may want to look

  to mixed effects models (e.g nlme, lme4) as another

  potential approach.


  On Tue, Jan 20, 2015 at

  11:35 PM, javad bayat via R-help <r-help at r-project.org>




  I am the new user of R. I want to simulation or

  the Eutrophication of a lake. I have weekly data(almost

  two years) for Total phosphorus, Total N, pH, Chlorophyll

  Alkalinity, Silica.

  Can I predict the Eutrophication by Neural Network in

  How can I simulation the Eutrophication by these


  please help me to write the codes.

  many thanks.


  R-help at r-project.org

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  PLEASE do read the posting guide http://www.R-project.org/posting-guide.html

  and provide commented, minimal, self-contained,



  Dr. Charles Determan, PhD

  Integrated Biosciences

 Dr. Charles Determan, PhD
 Integrated Biosciences

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