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Detect if value is number in MySQL
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answered Feb 21 '11 at 10:47
RichardTheKiwiRichardTheKiwi
96.3k2323 gold badges178178 silver badges250250 bronze badges
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What does the ^ operator do in Java?
...perator.
Let's take 5^6 as example:
(decimal) (binary)
5 = 101
6 = 110
------------------ xor
3 = 011
This the truth table for bitwise (JLS 15.22.1) and logical (JLS 15.22.2) xor:
^ | 0 1 ^ | F T
--+----- --+-----
0 | 0 1 F | F T
1 | 1 0 T | T...
Automatically expanding an R factor into a collection of 1/0 indicator variables for every factor le
...vel, there is an associated column in a new data frame, which contains a 1/0 indicator. E.g., suppose I have:
8 Answers
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Gray out image with CSS?
...age" src="something.jpg" />
</div>
css:
#myImage {
opacity: 0.4;
filter: alpha(opacity=40); /* msie */
}
/* or */
#wrapper {
opacity: 0.4;
filter: alpha(opacity=40); /* msie */
background-color: #000;
}
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Two color borders
...utline is inside of the shadow; in FireFox it is outside, so -moz-outline: 0 is useful to ensure that you don't get a gnarly line around your beautiful CSS drop shadow).
.someclass {
border: 1px solid blue;
outline: 1px solid darkblue;
}
Edit: Some people have remarked that outline doesn't ji...
SQL Logic Operator Precedence: And and Or
...e's an example to illustrate:
Declare @x tinyInt = 1
Declare @y tinyInt = 0
Declare @z tinyInt = 0
Select Case When @x=1 OR @y=1 And @z=1 Then 'T' Else 'F' End -- outputs T
Select Case When (@x=1 OR @y=1) And @z=1 Then 'T' Else 'F' End -- outputs F
For those who like to consult references (in al...
Regular expression for matching latitude/longitude coordinates?
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answered Aug 19 '10 at 3:38
Eric CEric C
3,55633 gold badges2828 silver badges2626 bronze badges
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Modifying a subset of rows in a pandas dataframe
...fy this DataFrame (or create a copy) so that B is always NaN whenever A is 0. How would I achieve that?
5 Answers
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deleting rows in numpy array
... [7,8,9]])
To delete the first row, do this:
x = numpy.delete(x, (0), axis=0)
To delete the third column, do this:
x = numpy.delete(x,(2), axis=1)
So you could find the indices of the rows which have a 0 in them, put them in a list or a tuple and pass this as the second argument of the...
Getting the array length of a 2D array in Java
... };
System.out.println(foo.length); //2
System.out.println(foo[0].length); //3
System.out.println(foo[1].length); //4
}
Column lengths differ per row. If you're backing some data by a fixed size 2D array, then provide getters to the fixed values in a wrapper class.
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