[R] How to keep plot title same as column name using apply/sapply?

[arun]

Hi,
You can try:
  par(mfrow=c(3, 2))
 mapply(hist,split(a,col(a)),main=colnames(a),xlab="x")


If you look at the output, 
mapply(hist,a,main=colnames(a),xlab="x")

         [,1]               [,2]               [,3]              
breaks   Numeric,2          Numeric,2          Numeric,2         
counts   1                  1                  1                 
density  2                  5                  20                
mids     0.75               0.3                0.025             
xname    "dots[[1L]][[1L]]" "dots[[1L]][[2L]]" "dots[[1L]][[3L]]"
equidist TRUE               TRUE               TRUE              
         [,4]               [,5]               [,6]              
breaks   Numeric,2          Numeric,2          Numeric,2         
counts   1                  1                  1                 
density  10                 5                  1                 
mids     0.15               0.3                0.5 

_____________________________________
         [,46]               [,47]               [,48]              
breaks   Numeric,2           Numeric,2           Numeric,2          
counts   1                   1                   1                  
density  0.002               0.01                0.02               
mids     -6250               -950                275                
xname    "dots[[1L]][[46L]]" "dots[[1L]][[47L]]" "dots[[1L]][[48L]]"
equidist TRUE                TRUE                TRUE               
         [,49]               [,50]              
breaks   Numeric,2           Numeric,2          
counts   1                   1                  
density  0.001               0.005              
mids     10500               3300               
xname    "dots[[1L]][[49L]]" "dots[[1L]][[50L]]"
equidist TRUE                TRUE               


#it is going through every single observation rather than by columns.
A.K.
      



----- Original Message -----
From: C W <tmrsg11 at gmail.com>
To: arun <smartpink111 at yahoo.com>
Cc: R help <r-help at r-project.org>
Sent: Thursday, April 18, 2013 7:20 PM
Subject: Re: [R] How to keep plot title same as column name using apply/sapply?

> mapply(hist,as.data.frame(a),main=colnames(a),xlab="x")

Why it does't work when I use "a" instead of "as.data.frame(a)"?
?mapply says "arguments to vectorize over (vectors or lists of
strictly positive length, or all of zero length)."

Thanks,
Mike

On Thu, Apr 18, 2013 at 6:49 PM, arun <smartpink111 at yahoo.com> wrote:
> Hi,
> Try:
>  par(mfrow=c(3, 2))
> mapply(hist,as.data.frame(a),main=colnames(a),xlab="x")
> A.K.
>
>
>
>
> ----- Original Message -----
> From: C W <tmrsg11 at gmail.com>
> To: r-help <r-help at r-project.org>
> Cc:
> Sent: Thursday, April 18, 2013 6:30 PM
> Subject: [R] How to keep plot title same as column name using apply/sapply?
>
> Dear list,
> I am trying to plot histogram of a 10 by 5 matrix by columns.
>
> What is a good way to paste the column names?
>
> dput(a)
> structure(c(0.891856482875103, 0.249593821948295, 0.0385066520473322,
> 0.109098868876336, 0.238035894186719, 0.971470380855763, 0.168018536530906,
> 0.941457062296419, -0.285381460315397, -0.0229335863796271, -20138.175683257,
> 28190.7238887329, 8521.44473371867, 37565.8599592035, -61036.6139527803,
> -57278.42539968, 24284.2860193156, 57470.8275786857, -5035.05919672665,
> -48223.3060594833, 0.105003428645432, 0.0385466025676578, 0.130895042931661,
> 0.0682065344415605, 0.155879093753174, 0.0598988083656877, 0.121624303748831,
> 0.120134906983003, 0.159434637567028, 0.0144033632241189, 6133.33965969139,
> 5363.20408479208, 22432.8473630982, 10627.5697498379, 273.481263455154,
> 8326.07386291277, 133.117356408579, 4108.23352922685, 643.558745779806,
> 5532.10081652847, -4512.80115728638, -5839.1178791698, 7341.05048720629,
> -1299.37511688102, -13151.5558568303, -6442.78100296569, -975.590624649323,
> 298.440121450997, 10808.9562034117, 3210.22497745543), .Dim = c(10L,
> 5L), .Dimnames = list(NULL, c("Tmrw", "hRm2", "vm", "Fluid",
> "SM")))
> par(mfrow=c(3, 2))
> apply(a, 2, function(x){hist(x, main="column name here")})
>
> This plots, but doesn't plot title.
>
> But,
>> apply(a,2,function(x){colnames(x)})
> NULL
>
> Maybe the column names is lost?  But, I see column names here.
>
>> apply(a,2,function(x){is.vector(x)})
> Tmrw  hRm2    vm Fluid    SM
> TRUE  TRUE  TRUE  TRUE  TRUE
>
> My understanding is that, apply() takes data matrix column by column,
> and pastes names back on at the end?  But I need it for plot title,
> how should I change my code?
>
> Thanks,
> Mike
>
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