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POWhy does mapply repeat the same list multiple times?
 

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  1. POWhy does mapply repeat the same list multiple times?
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    <p>Please let me start by providing synthetic data set that shows the issues:</p> <pre><code>Do &lt;- rep(c(0,2,4,6,8,10,15,20,30,40,45,50,55,60,65,70,80,85,90,92,94,96,98,100), each=16,times=16) Cl &lt;- rep(c("K", "Y","M","C"), each= 384, times=4) In &lt;- rep(c("A", "S"), each=3072) Sa &lt;- rep(c(1,2), each=1536) Data &lt;- rnorm(6144) DataFrame &lt;- cbind.data.frame(Do,Cl,In,Sa,Data); head(DataFrame) rm(Do,Cl,In,Sa,Data) attach(DataFrame) </code></pre> <p>Next, I split the 'DataFrame' object into multiple lists to avoid unpredictable recycling. Basically, I am placing each data subset in a separate list so that cycling is predictable and that produced the correct output in my simulator.</p> <pre><code>DFSplit &lt;- split(DataFrame[ , "Data"], list(Do, Cl, In, Sa)) </code></pre> <p>The 'DFSplit' object has 384 lists</p> <pre><code>length(names(DFSplit)) </code></pre> <p>Then I created the function 'ids' to identify the lists names</p> <pre><code>ids &lt;- function(Do, Cl, In, Sa){ grep( paste( "^" , Do, "\\.", Cl, "\\.", In, "\\.", Sa,sep=""), names(DFSplit), value = TRUE)} mapply(ids, Do, Cl, In, Sa, SIMPLIFY = FALSE) </code></pre> <p>I understand that each of 'ids' arguments' length is 6144. mapply produces 384 lists each repeated 16 times. How can I change the ids function so that mapply doesn't repeat the same name 16 times. As an ugly and highly costly solution I used unique; i need a better fundamental solution. </p> <pre><code>unique(mapply(ids, Do, Cl, In, Sa, SIMPLIFY = FALSE)) </code></pre> <p>I also created a function to operate on the 'DFSplit' lists. It has the same issue as the previous function. The thing is, it accepts the previous function as an input.</p> <pre><code>dG &lt;- function(Do,Cl, In, Sa){ dg &lt;- 100* (1-10^-( DFSplit[[ids(Do, Cl, In, Sa)]] - DFSplit[[ids(0, Cl, In, Sa)]])) / (1-10^-( DFSplit[[ids(100, Cl, In, Sa)]] - DFSplit[[ids(0, Cl, In, Sa)]])) - Do dg} mapply(dG, Do, Cl, In, Sa, SIMPLIFY = FALSE) </code></pre> <p>What I am trying to do, unsuccessfully if I may say, is to apply the dG function inside each of the 384 lists. I acknowledge that dG function also needs to be modified and I don't know how. I want the input to the dG function to be the names of 384 lists each containing 16 numbers. I want the output to be 384 list with the dG applied.</p> <p>Please feel free to suggest a different solution all together. The important thing is I need to apply the 'dG' function to the data set.</p>
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    1. USRagy Isaac
    1. USRagy Isaac
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      1. POWhy does mapply repeat the same list multiple times?
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    1. COWhat is it what you want to accomplish? Your solution looks rather complex...
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      1. USPaul Hiemstra
    2. COHi Paul, I have been working on this for a week without success. I am trying to apply the 'dG' function to my data:'DataFrame'. Unfortunately I have not been successful since the arguments' lengths differ and recycling produced incorrect calculation. So I separated the file into lists, identified the name of each list and then applied the function dG.
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      1. USRagy Isaac
    3. COI can't really figure out what you're actually trying to accomplish from this code. But I'm surprised that you're surprised that your result is of length 6144. Each argument that you pass to the function `dG` is of length 6144.
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      1. USjoran
 

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