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R - Concatenate two dataframes?
...
227
You want "rbind".
b$b <- NA
new <- rbind(a, b)
rbind requires the data frames to have...
Logical operators for boolean indexing in Pandas
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219
When you say
(a['x']==1) and (a['y']==10)
You are implicitly asking Python to convert (a['x...
Script parameters in Bash
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125
The arguments that you provide to a bashscript will appear in the variables $1 and $2 and $3 wh...
Remove duplicated rows using dplyr
...tion for this purpose.
Original answer below:
library(dplyr)
set.seed(123)
df <- data.frame(
x = sample(0:1, 10, replace = T),
y = sample(0:1, 10, replace = T),
z = 1:10
)
One approach would be to group, and then only keep the first row:
df %>% group_by(x, y) %>% filter(row_num...
How to select rows with one or more nulls from a pandas DataFrame without listing columns explicitly
...p.NaN], range(3), range(3)])
>>> df.isnull()
0 1 2
0 False False False
1 False True False
2 False False True
3 False False False
4 False False False
>>> df.isnull().any(axis=1)
0 False
1 True
2 True
3 False
4 False
dtype: bool
>...
Iterate a list with indexes in Python
... 19] and makes it into iterable list of tuples, like so: [(0,3), (1,7), (2,19)] to use it instead of:
6 Answers
...
No secret option provided to Rack::Session::Cookie warning?
I am running Rails 3.2.3, Ruby 1.9 under Fedora 17. I get this warning, when I run rails s , and how do I fix?
7 Answers
...
How to get device make and model on iOS?
...elName)
The result should be:
// Output on a simulator
@"i386" on 32-bit Simulator
@"x86_64" on 64-bit Simulator
// Output on an iPhone
@"iPhone1,1" on iPhone
@"iPhone1,2" on iPhone 3G
@"iPhone2,1" on iPhone 3GS
@"iPhone3,1" on iPhone 4 (GSM)
@"iPhone3,2" on iPhone 4 (GSM Rev A)
@"iPhone...
Why does ~True result in -2?
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240
int(True) is 1.
1 is:
00000001
and ~1 is:
11111110
Which is -2 in Two's complement1
1 ...
Multiple linear regression in Python
...ress my dependent variable (y) against several independent variables (x1, x2, x3, etc.).
13 Answers
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