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Convert a row of a data frame to vector
...u have to be careful if your row contains a factor. Here is an example:
df_1 = data.frame(V1 = factor(11:15),
V2 = 21:25)
df_1[1,] %>% as.numeric() # you expect 11 21 but it returns
[1] 1 21
Here is another example (by default data.frame() converts characters to factors)
d...
Understanding typedefs for function pointers in C
... can use it to declare variables and so on. For example:
static void alarm_catcher(int signum)
{
fprintf(stderr, "%s() called (%d)\n", __func__, signum);
}
static void signal_catcher(int signum)
{
fprintf(stderr, "%s() called (%d) - exiting\n", __func__, signum);
exit(1);
}
static str...
What is the JavaScript equivalent of var_dump or print_r in PHP? [duplicate]
...e of object in JavaScript (for debugging). Is there anything similar to var_dump in PHP?
9 Answers
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How to use JavaScript source maps (.map files)?
...using the minified code instead of the full, unminified version. When your app is in production, and has an error, the sourcemap will help take your ugly file, and will allow you to see the original version of the code. If you didn't have the sourcemap, then any error would seem cryptic at best.
Sam...
How do I get indices of N maximum values in a NumPy array?
...t;> a = [1, 3, 2, 4, 5]
>>> heapq.nlargest(3, range(len(a)), a.__getitem__)
[4, 3, 1]
If you use Python 2, use xrange instead of range.
Source: heapq — Heap queue algorithm
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Is there a typical state machine implementation pattern?
... use a table driven approach for most state machines:
typedef enum { STATE_INITIAL, STATE_FOO, STATE_BAR, NUM_STATES } state_t;
typedef struct instance_data instance_data_t;
typedef state_t state_func_t( instance_data_t *data );
state_t do_state_initial( instance_data_t *data );
state_t do_state_f...
Passing parameters to a Bash function
...s of declaring a function. I prefer the second approach.
function function_name {
command...
}
or
function_name () {
command...
}
To call a function with arguments:
function_name "$arg1" "$arg2"
The function refers to passed arguments by their position (not by name), that is $1, $2...
Get bitcoin historical data [closed]
...ocket in higher resolution over longer time period you could use script log_bitstamp_trades.py below.
The script uses python websocket-client and pusher_client_python libraries, so install them.
#!/usr/bin/python
import pusherclient
import time
import logging
import sys
import datetime
import sig...
What is the purpose of the vshost.exe file?
When I create and compile a "Hello, World!" application in C#, I get three files in the Debug folder apart from the main exe (e.g. HelloWorld.exe)
...
How to convert An NSInteger to an int?
...endently of whether you are building for a 32-bit or a 64-bit system.
#if __LP64__ || TARGET_OS_EMBEDDED || TARGET_OS_IPHONE || TARGET_OS_WIN32 || NS_BUILD_32_LIKE_64
typedef long NSInteger;
#else
typedef int NSInteger;
#endif
You can use NSInteger any place you use an int without converting it....