Programming the statistical procedures from SAS

How to calculate if my plants died ?

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Occasional Contributor
Posts: 16
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How to calculate if my plants died ?

Hi,

I'm elementary user of SAS. I am working on agricultural research and my experiment was laid out in split plot design.

However, I'm facing a problem, in which several plants had died, even of plants in one of the treatment combination.

So, what should I do ?

Ok, I'll explain my data;

A1     B1     1      died

A1     B1     2      20

A1     B1     3      died

A1     B1     4      died

A1     B1     5      died

A1     B2     1      died

A1     B2     2      13

A1     B2     3      died

A1     B2     4      12

A1     B2     5      10

A1     B3     1      died

A1     B3     2      died

A1     B3     3      died

A1     B3     4      15

A1     B3     5      17

A2     B1     1      died

A2     B1     2      died

A2     B1     3      died

A2     B1     4      died

A2     B1     5      died

A2     B2     1      died

A2     B2     2      28

A2     B2     3      died

A2     B2     4      died

A2     B2     5      30

A2     B3     1      17

A2     B3     2      15

A2     B3     3      16

A2     B3     4      died

A2     B3     5      18

A3     B1     1      5

A3     B1     2      died

A3     B1     3      10

A3     B1     4      died

A3     B1     5      died

A3     B2     1      died

A3     B2     2      10

A3     B2     3      8

A3     B2     4      9

A3     B2     5      died

A3     B3     1      died

A3     B3     2      5

A3     B3     3      died

A3     B3     4      10

A3     B3     5      6


It would be appreciated if you could help me


A very big thank you for your help


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‎08-20-2015 11:13 AM
Valued Guide
Valued Guide
Posts: 673

Re: How to calculate if my plants died ?

It all depends if the deaths are due to the treatment. If they are, then your dead plants cannot be considered missing at random, and you have problems. You can treat plant death as a binary variable (0: alive, 1: dead, one value for each record) and analyze the data as a generalized linear mixed model (check out the SAS User's Guide for GLIMMIX).

     model z = A|B / dist=bin link=logit;

if z is the binary variable. See the rest of the code in your other posts for this split plot.

This idea is ignoring the quantitative response variable where the plants did not die. If plant death is related to treatment, then you can definitely NOT analyze the continuous variables for the alive plants. If plant death is unrelated to the treatments (unlikely), you could analyze the rest of the data (you don't have to do anything special). You have a lot of dead plants, so you probably need better experimental methods -- statistics cannot rescue an experiment that should not be analyzed.

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Occasional Contributor
Posts: 16

Re: How to calculate if my plants died ?

After I read several statistic book I knew that is missing value, but how to create the codes using SAS ? It would be appriciated if you could help me

Esteemed Advisor
Esteemed Advisor
Posts: 6,959

Re: How to calculate if my plants died ?

Errrm, water them more?  Sorry, sarcasm aside, you have not specified any problem.  Try rephrasing it with test data (just a small amount) in the form of a datastep.  Provide example required output, and clarify any logical steps.

Solution
‎08-20-2015 11:13 AM
Valued Guide
Valued Guide
Posts: 673

Re: How to calculate if my plants died ?

It all depends if the deaths are due to the treatment. If they are, then your dead plants cannot be considered missing at random, and you have problems. You can treat plant death as a binary variable (0: alive, 1: dead, one value for each record) and analyze the data as a generalized linear mixed model (check out the SAS User's Guide for GLIMMIX).

     model z = A|B / dist=bin link=logit;

if z is the binary variable. See the rest of the code in your other posts for this split plot.

This idea is ignoring the quantitative response variable where the plants did not die. If plant death is related to treatment, then you can definitely NOT analyze the continuous variables for the alive plants. If plant death is unrelated to the treatments (unlikely), you could analyze the rest of the data (you don't have to do anything special). You have a lot of dead plants, so you probably need better experimental methods -- statistics cannot rescue an experiment that should not be analyzed.

SAS Super FREQ
Posts: 3,301

Re: How to calculate if my plants died ?

@lvm's response reminds me of a famous quote by R. Fisher: "To consult the statistician after an experiment is finished is often merely to ask him to conduct a post mortem examination. He can perhaps say what the experiment died of."

Occasional Contributor
Posts: 16

Re: How to calculate if my plants died ?

A very big thank you @lvm, @RW9, and @Rick Wicklin

Occasional Contributor
Posts: 16

Re: How to calculate if my plants died ?

My experiment arranged in Split Plot design. How to make a Charts/ Boxplots for Proportions of a Binary Variable ?

data Survival;

  input A $ B $ Block Y;  if Y=1 then 1='Survive'; else 0='Died';

datalines;

A1     B1     1      0

A1     B1     2      1

A1     B1     3      0

A1     B1     4      0

A1     B1     5      0

A1     B2     1      1

A1     B2     2      1

A1     B2     3      1

A1     B2     4      1

A1     B2     5      0

A1     B3     1      1

A1     B3     2      0

A1     B3     3      0

A1     B3     4      1

A1     B3     5      1

A2     B1     1      0

A2     B1     2      0

A2     B1     3      0

A2     B1     4      0

A2     B1     5      0

A2     B2     1      1

A2     B2     2      0

A2     B2     3      0

A2     B2     4      1

A2     B2     5      0

A2     B3     1      1

A2     B3     2      1

A2     B3     3      1

A2     B3     4      0

A2     B3     5      1

A3     B1     1      1

A3     B1     2      0

A3     B1     3      1

A3     B1     4      0

A3     B1     5      0

A3     B2     1      0

A3     B2     2      1

A3     B2     3      1

A3     B2     4      1

A3     B2     5      0

A3     B3     1      0

A3     B3     2      1

A3     B3     3      0

A3     B3     4      1

A3     B3     5      1

;

 

Is it true when it displayed in as shown below ? how to write the codes

 

 

original.jpg

 

 

Please help me it is so important for me...

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