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How to Correctly Use Lists in R?
...:
Why do these two expressions not return the same result?
x = list(1, 2, 3, 4); x2 = list(1:4)
A list can contain any other class as each element. So you can have a list where the first element is a character vector, the second is a data frame, etc. In this case, you have created two different ...
How to update Identity Column in SQL Server?
...n the identity column
INSERT INTO YourTable(IdentityCol, otherCol) VALUES(13,'myValue')
GO
-- Delete the old row of which you have inserted a copy (above) (make sure about FK's)
DELETE FROM YourTable WHERE ID=3
GO
--Now set the idenetity_insert OFF to back to the previous track
SET IDENTITY_INSERT Y...
HTML5 Canvas Resize (Downscale) Image High Quality?
...e. )
Here's an example of canvas scale vs my pixel perfect scale on a 1/3 scale of a zombat.
Notice that the picture might get scaled in your Browser, and is .jpegized by S.O..
Yet we see that there's much less noise especially in the grass behind the wombat, and the branches on its right. The n...
Numpy array dimensions
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513
It is .shape:
ndarray.shape
Tuple of array dimensions.
Thus:
>>> a.shape
(2, 2...
Bootstrap 3 Glyphicons are not working
I downloaded bootstrap 3.0 and can't get the glyphicons to work. I get some kind of "E003" error. Any ideas why this is happening? I tried both locally and online and I still get the same problem.
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How to get the nth element of a python list or a default if not available
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gruszczygruszczy
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Read user input inside a loop
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answered Jul 30 '11 at 13:42
dankdank
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Pass a data.frame column name to a function
... just use the column name directly:
df <- data.frame(A=1:10, B=2:11, C=3:12)
fun1 <- function(x, column){
max(x[,column])
}
fun1(df, "B")
fun1(df, c("B","A"))
There's no need to use substitute, eval, etc.
You can even pass the desired function as a parameter:
fun1 <- function(x, colu...
Why can't R's ifelse statements return vectors?
...tors, you will get longer results:
> ifelse(c(TRUE, FALSE), c(1, 2), c(3, 4))
[1] 1 4
So ifelse is intended for the specific purpose of testing a vector of booleans and returning a vector of the same length, filled with elements taken from the (vector) yes and no arguments.
It is a common con...
Repeat each row of data.frame the number of times specified in a column
...), 1:2]
Result:
var1 var2
1 a d
2 b e
2.1 b e
3 c f
3.1 c f
3.2 c f
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