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Apply a function to every row of a matrix or a data frame
... 3 4
[3,] 5 6
R> apply(M, 1, function(x) 2*x[1]+x[2])
[1] 4 10 16
R>
This takes a matrix and applies a (silly) function to each row. You pass extra arguments to the function as fourth, fifth, ... arguments to apply().
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Why use strong named assemblies?
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edited Jun 10 at 14:18
Jan Nils Ferner
2,81422 gold badges1414 silver badges3131 bronze badges
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How to catch integer(0)?
Let's say we have a statement that produces integer(0) , e.g.
6 Answers
6
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SSH library for Java [closed]
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answered Jun 15 '09 at 14:27
David RabinowitzDavid Rabinowitz
27.2k1313 gold badges8585 silver badges123123 bronze badges
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Delete topic in Kafka 0.8.1.1
I need to delete the topic test in Apache Kafka 0.8.1.1.
14 Answers
14
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Delete element in a slice
... arguments to a variadic function.
So what this line does:
a = append(a[:0], a[1:]...)
is essentially:
a = append(a[:0], a[1], a[2])
Now, you may be wondering, why not just do
a = append(a[1:]...)
Well, the function definition of append is
func append(slice []Type, elems ...Type) []Type
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How can I remove the decimal part from JavaScript number?
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403
You could use...
Math.trunc() (truncate fractional part, also see below)
Math.floor() (round ...
Do you use NULL or 0 (zero) for pointers in C++?
...as bolted on top of C, you could not use NULL as it was defined as (void*)0 . You could not assign NULL to any pointer other than void* , which made it kind of useless. Back in those days, it was accepted that you used 0 (zero) for null pointers.
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Plot yerr/xerr as shaded region rather than error bars
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from matplotlib import pyplot as plt
import numpy as np
x = np.linspace(0, 30, 30)
y = np.sin(x/6*np.pi)
error = np.random.normal(0.1, 0.02, size=y.shape)
y += np.random.normal(0, 0.1, size=y.shape)
plt.plot(x, y, 'k-')
plt.fill_between(x, y-error, y+error)
plt.show()
See also the matplotlib...
How can I have two fixed width columns with one flexible column in the center?
...sing width (which is a suggestion when using flexbox), you could use flex: 0 0 230px; which means:
0 = don't grow (shorthand for flex-grow)
0 = don't shrink (shorthand for flex-shrink)
230px = start at 230px (shorthand for flex-basis)
which means: always be 230px.
See fiddle, thanks @TylerH
Oh...