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Use of ~ (tilde) in R programming Language
...".
The myFormula <- part of that line stores the formula in an object called myFormula so you can use it in other parts of your R code.
Other common uses of formula objects in R
The lattice package uses them to specify the variables to plot.
The ggplot2 package uses them to specify panels fo...
Convert XML String to Object
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You need to use the xsd.exe tool which gets installed with the Windows SDK into a directory something similar to:
C:\Program Files\Microsoft SDKs\Windows\v6.0A\bin
And on 64-bit computers:
C:\Program Files (x86)\Microsoft SDKs\Windows\v6.0A\bin
And on Windows 10 com...
Is it a good idea to index datetime field in mysql?
...atabase is very broad. I'd say to just make sure that it's normalized and all appropriate columns are indexed (i.e. ones used in joins and where clauses).
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Jump to matching XML tags in Vim
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There is a vim plugin called matchit.vim . You can find it here: http://www.vim.org/scripts/script.php?script_id=39 . It was created pretty much the exact purpose you describe.
Install that, place your cursor on the body of the tag (not the <&g...
How can I see the SQL that will be generated by a given ActiveRecord query in Ruby on Rails
...query has been issued, but I'm wondering if there is a method that can be called on and ActiveRecord Query.
11 Answers
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Tracing XML request/responses with JAX-WS
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Following options enable logging of all communication to the console (technically, you only need one of these, but that depends on the libraries you use, so setting all four is safer option). You can set it in the code like in example, or as command line parame...
Get records with max value for each group of grouped SQL results
..., age desc, Person) x
group by `Group`
This works because in mysql you're allowed to not aggregate non-group-by columns, in which case mysql just returns the first row. The solution is to first order the data such that for each group the row you want is first, then group by the columns you want the...
Cleaning `Inf` values from an R dataframe
...ption 1
Use the fact that a data.frame is a list of columns, then use do.call to recreate a data.frame.
do.call(data.frame,lapply(DT, function(x) replace(x, is.infinite(x),NA)))
Option 2 -- data.table
You could use data.table and set. This avoids some internal copying.
DT <- data.table(dat)...
How to move columns in a MySQL table?
...erform on a large table? Is it just changing some metadata, or does it actually have to reorganize data on the disk?
– Kip
Nov 12 '15 at 16:01
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Logical operator in a handlebars.js {{#if}} conditional
... options.fn(this);
}
return options.inverse(this);
});
You can then call the helper in the template like this
{{#ifCond v1 v2}}
{{v1}} is equal to {{v2}}
{{else}}
{{v1}} is not equal to {{v2}}
{{/ifCond}}
sha...