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How to select the rows with maximum values in each group with dplyr? [duplicate]
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Try this:
result <- df %>%
group_by(A, B) %>%
filter(value == max(value)) %>%
arrange(A,B,C)
Seems to work:
identical(
as.data.frame(result),
ddply(df, .(A, B), function(x) x[which.max(x$value),])
)
#[1] TRUE
As pointed ...
SQL WHERE.. IN clause multiple columns
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You can make a derived table from the subquery, and join table1 to this derived table:
select * from table1 LEFT JOIN
(
Select CM_PLAN_ID, Individual_ID
From CRM_VCM_CURRENT_LEAD_STATUS
Where Lead_Key = :_Lead_Key
) table2
ON
table1.CM...
What is the most efficient way to create a dictionary of two pandas Dataframe columns?
....Series(df.Letter.values,index=df.Position).to_dict()
Out[9]: {1: 'a', 2: 'b', 3: 'c', 4: 'd', 5: 'e'}
Speed comparion (using Wouter's method)
In [6]: df = pd.DataFrame(randint(0,10,10000).reshape(5000,2),columns=list('AB'))
In [7]: %timeit dict(zip(df.A,df.B))
1000 loops, best of 3: 1.27 ms per...
Git: How to rebase to a specific commit?
I'd like to rebase to a specific commit, not to a HEAD of the other branch:
9 Answers
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Why do we need virtual functions in C++?
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Here is how I understood not just what virtual functions are, but why they're required:
Let's say you have these two classes:
class Animal
{
public:
void eat() { std::cout << "I'm eating generic food."; }
};
class Cat : public Animal
{
public:
void eat()...
How to select rows from a DataFrame based on column values?
How to select rows from a DataFrame based on values in some column in Pandas?
10 Answers
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Select multiple columns in data.table by their numeric indices
...iple columns using a vector of their numeric indices (position) in data.table ?
5 Answers
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MSBuild doesn't copy references (DLL files) if using project dependencies in solution
...cts in my Visual Studio solution (everyone targeting .NET 3.5) - for my problem only these two are important:
19 Answers
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URL Encoding using C#
I have an application which sends a POST request to the VB forum software and logs someone in (without setting cookies or anything).
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How to invoke the super constructor in Python?
...implicitly. How does one invoke it in Python? I would expect super(self) but this doesn't work.
7 Answers
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