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If I have a data.frame that contain the variables that listed in df$Var. Is it a way for me to reorder my data col in the order of df$Var?
The df is looks like this:
Is it a way I can sort dt so the col in dt will in the order of var in df?
Thanks.
We can use factor with levels specified as the values in 'df1$Var'
dt1[order(factor(names(dt1), levels = df1$Var))]
Or use match
dt1[order(match(names(dt1), df1$Var))]
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Looking for other way than ifelse.
How to create NewColumn like this:
As displayed in your picture, you want to paste together two columns. Assuming your dataframe is called df, you can do:
df$NewColumn <- paste(df$Column2,"",df$Column1)
Which will get you the outcome in the picture.
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I need to iterate a sequence that is being repeated.
Say I have a vector of 1,2,3 I want printed out 5 times.
each time needs to be inceased by one.
so 1,2,3,2,3,4,3,4,5,4,5,6,5,6,7
rep(1:3, 5) + rep(0:4, each=3)
should do the trick
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Data sample is below: I have 3million rows.
Date,id,type,qty
9/30/14,1,’A’,10
9/30/14,2,’Z’,12
9/30/14,3,’B’,15
9/30/14,1,’B’,20
9/30/14,1,’Z’,20
9/30/14,1,’A’,20
9/30/14,2,’B’,20
9/30/14,3,’B’,5
9/30/14,3,’A’,40
I want result as below:
Date,id,type,Qty
9/30/14,1,A,20
9/30/14,1,B,20
9/30/14,2,B,20
9/30/14,3,B,5
9/30/14,3,’A’,40
Logic is below: On the same date, pick the latest qty (from the later record) for each id and type.Ignore types y and Z.
DT[,.(Qty=last(qty)),by=.(Date,id,type)][type!='Z'][order(id)]
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I want to calculate which value correspond to 80% of a column data in order to use this value as a limit value (Xlimit). After that I want to get column data>Xlimit.
Try this
x = data.frame(a=sample(1:10),b=sample(1:10))
aLim = quantile(x$a,0.8)
xUpdated = x[x$a>=aLim,]