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Numbering rows within groups in a data frame
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Use ave, ddply, dplyr or data.table:
df$num <- ave(df$val, df$cat, FUN = seq_along)
or:
library(plyr)
ddply(df, .(cat), mutate, id = seq_along(val))
or:
library(dplyr)
df %>% group_by(cat) %>% mutate(id = row_number())
or (the most memory efficient, as it assigns by reference w...
Place cursor at the end of text in EditText
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There is a function called append for ediitext which appends the string value to current edittext value and places the cursor at the end of the value.
You can have the string value as the current ediitext value itself and call append();...
Finding all objects that have a given property inside a collection [duplicate]
...st for the Matchers. Some will argue that this is not Java-style, but it's fun how this guy twisted Java to make a bit of functional programming. Have a look at the source code also, it's quite sci-fi.
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How do I show the value of a #define at compile-time?
... GCC terminology seems to have changed, and with it the URL, which is now https://gcc.gnu.org/onlinedocs/cpp/Stringizing.html#Stringizing
– Chris Barry
Aug 29 '19 at 11:14
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Find index of last occurrence of a sub-string using T-SQL
...ng using SQL? I am using SQL Server 2000 right now. I basically need the functionality that the .NET System.String.LastIndexOf method provides. A little googling revealed this - Function To Retrieve Last Index - but that does not work if you pass in a "text" column expression. Other solution...
Heatmap in matplotlib with pcolor?
...ay
ax.invert_yaxis()
ax.xaxis.tick_top()
# Set the labels
# label source:https://en.wikipedia.org/wiki/Basketball_statistics
labels = [
'Games', 'Minutes', 'Points', 'Field goals made', 'Field goal attempts', 'Field goal percentage', 'Free throws made', 'Free throws attempts', 'Free throws per...
CSS opacity only to background color, not the text on it? [duplicate]
...use a transparent background, in which case you could try using the rgba() function:
rgba(R, G, B, A)
R (red), G (green), and B (blue) can be either <integer>s or <percentage>s, where the number 255 corresponds to 100%. A (alpha) can be a <number> between 0 and 1, or a <percent...
Why is it recommended to have empty line in the end of a source file?
...ill actually read right up to the EOF marker so that the runtime library's function of reading from input will know when to stop reading any further. When you open the stream for Append mode, it will wipe the EOF marker and write past it, until a close is explicitly called in which it will insert th...
how to stop Javascript forEach? [duplicate]
... trying to find specific comment in deep comments nesting with recursive function and forEach within. Is there a way to stop Node.js forEach ? As I understand every forEach iteration is a function and and I can't just do break , only return but this won't stop forEach .
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Create Generic method constraining T to an Enum
... but is possible in MSIL. I wrote this little....thing
// license: http://www.apache.org/licenses/LICENSE-2.0.html
.assembly MyThing{}
.class public abstract sealed MyThing.Thing
extends [mscorlib]System.Object
{
.method public static !!T GetEnumFromString<valuetype .ctor ([mscorlib]Sy...