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How to sum a variable by group
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404
Using aggregate:
aggregate(x$Frequency, by=list(Category=x$Category), FUN=sum)
Category x
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Check for internet connection availability in Swift
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10 Answers
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Adding a y-axis label to secondary y-axis in matplotlib
...directly
import numpy as np
import matplotlib.pyplot as plt
x = np.arange(0, 10, 0.1)
y1 = 0.05 * x**2
y2 = -1 *y1
fig, ax1 = plt.subplots()
ax2 = ax1.twinx()
ax1.plot(x, y1, 'g-')
ax2.plot(x, y2, 'b-')
ax1.set_xlabel('X data')
ax1.set_ylabel('Y1 data', color='g')
ax2.set_ylabel('Y2 data', color...
How to get first N elements of a list in C#?
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answered Nov 26 '08 at 7:28
Matt HamiltonMatt Hamilton
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Why does C++ rand() seem to generate only numbers of the same order of magnitude?
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There are only 3% of numbers between 1 and 230 which are NOT between 225 and 230. So, this sounds pretty normal :)
Because 225 / 230 = 2-5 = 1/32 = 0.03125 = 3.125%
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remove None value from a list without removing the 0 value
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10 Answers
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Install go with brew, and running the gotour
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Custodio
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answered Dec 30 '14 at 17:36
user2562923user2...
Android Studio 0.4 Duplicate files copied in APK META-INF/LICENSE.txt
After I have updated my Studio from 0.3.7 to 0.4.0, I can't compile my project. I found a solution on stackoverflow: Duplicate files copied (Android Studio 0.4.0)
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What is the fastest factorial function in JavaScript? [closed]
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110
You can search for (1...100)! on Wolfram|Alpha to pre-calculate the factorial sequence.
The firs...
How to reuse an ostringstream?
...lear, then seek the appropriate sequence to the begin:
s.clear();
s.seekp(0); // for outputs: seek put ptr to start
s.seekg(0); // for inputs: seek get ptr to start
That will prevent some reallocations done by str by overwriting whatever is in the output buffer currently instead. Results are like...