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Difference between Select and ConvertAll in C#
...INQ extension method and works on all IEnumerable<T> objects whereas ConvertAll is implemented only by List<T>. The ConvertAll method exists since .NET 2.0 whereas LINQ was introduced with 3.5.
You should favor Select over ConvertAll as it works for any kind of list, but they do the sam...
What is the best method of handling currency/money?
...e calculation.
If you insist on using integers, you will have to manually convert to and from BigDecimals everywhere, which will probably just become a pain.
As pointed out by mcl, to print the price, use:
number_to_currency(price, :unit => "€")
#=> €1,234.01
...
Why does ('0' ? 'a' : 'b') behave different than ('0' == true ? 'a' : 'b') [duplicate]
... return the result of the comparison x == ToNumber(y).
When booleans are converted to numbers, the following conversion takes place:
Boolean: The result is 1 if the argument is true. The result is +0 if the argument is false.
Now we have
'0' == 1
which matches the condition in step 5:
...
Understanding ibeacon distancing
...ually the difference in dB. So:
ratio_dB = txCalibratedPower - RSSI
To convert that into a linear ratio, we use the standard formula for dB:
ratio_linear = 10 ^ (ratio_dB / 10)
If we assume conservation of energy, then the signal strength must fall off as 1/r^2. So:
power = power_at_1_meter...
Is Python interpreted, or compiled, or both?
...tion to native machine code. A compiler is, more generally, a program that converts a program in one programming language into a program in another programming language (arguably, you can even have a compiler with the same input and output language if significant transformations are applied). And JI...
What does .SD stand for in data.table in R
...
Edit:
Given how well-received this answer was, I've converted it into a package vignette now available here
Given how often this comes up, I think this warrants a bit more exposition, beyond the helpful answer given by Josh O'Brien above.
In addition to the Subset of the D...
Replace tabs with spaces in vim
I would like to convert tab to spaces in gVim. I added the following line to my _vimrc :
11 Answers
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RGB to hex and hex to RGB
How to convert colors in RGB format to hex format and vice versa?
50 Answers
50
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How does Google's Page Speed lossless image compression work?
...sion(0), alpha_filtering(1), alpha_quality(100) {}
There is also image_converter.cc which is used to losslessly convert to the smallest format.
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How to use the 'sweep' function
...,sd))
df_T=sweep(sweep(df,2,df_means,"-"),2,df_sds,"/")*10+50
This code convert raw scores to T scores (with mean=50 and sd=10):
> df
[,1] [,2] [,3] [,4] [,5]
[1,] 109 8 89 69 15
[2,] 85 13 25 150 26
[3,] 30 79 48 1 125
[4,] 56 74 23 140 100
[5,] 136...