zeros

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    PRIMER- MDS-shows identical biological community samples equally different, WHY?

    Hi, I have a large data set of marine intertidal organism abundance (measured as percent cover. I also have environmental data of substrate type, and beach exposure to wind/waves. The research question is “Do unconsolidated beaches (eg. sand or gravel, not bedrock) have different communities...
  2. M

    [R]: Mixed model for non-normal y with many 0s and some high values in nested design

    Dear all, I am currently writing my master thesis on the effect of a certain insecticide on bumble bee colonies. In particular I am testing whether the insecticide affects virus or bacterium concentrations. In many colonies I haven’t found any viruses, but if they are present they can be in...
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    SPSS Tranformation using Log10(variable+1) not working

    Hi, I'm trying to transform a positively skewed variable that includes 10 zeros, so I understand that when using the Log10 function, '+1' should be added, and then all the zeros would become 1. I have performed this, and although the distribution of the variable seems better, unfortunately...
  4. A

    replacing missing values for zeros in a loop

    Hello Stata experts, I am working in panel data with dyadic data and years. My data base is like the following: pair year fdi 1 2005 . 1 2006 . 1 2007 . 1 2008 . 1 2009 0 1 2010 0 1 2011 0 2 2005 . 2 2006 . 2 2007 . 2 2008 0 2 2009 0 2 2010 . 2 2011 . 3 2005 . 3 2006 . 3 2007 . 3 2008 2 3 2009 4...
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    Throwing out zeros from a faulty sensor

    I'm fairly new at stats. I have time-series data from a sensor. There are a lot of zeros in the data -- 70% of readings -- and those seem improbable physically. By visual inspection they seem to be faults, but the data otherwise looks like I expect it to. I plan to just throw away the zeros...
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    What statistics to use to find a possible correlation of coinciding null results?

    I would like your advice on the following problem: I am investigating the following data: For 600 trials data was gathered simultaneously from two sources (locations in rats brain). Each trial was investigated and either a result was found (some time stamp) or no result was found (a "zero...
  7. S

    Kruskal Wallis test and problem with zeros

    Hi. I am conducting a biological research about species abundance variations between different hours and localitions. I am comparing 11 different locations and 5 different hours. Independent variables are hour and locality. Dependent variables are abundances of each species found in...
  8. M

    Life data analysis zero time failures problem

    Hi, I have life data which contains time to failures of zero, I'm really not sure which distribution I should use to analyse this data, i've tried using a weibull distribution in software such as mintab and Weibull++ but they either ignore the data when calculating the parameters or do not...
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    Low correlation, but significative p-value

    Hello, I have a sample n=522, and did a spearman correlation with the result coeffeciente 0,27 **, wich indicates that there isnt a relation. However the p-valu is <0,05. My sample has a several 0 wich i belevie is the awnser to this results. Is it true? What can i think of this...