dergachev

OS X Screencast to animated GIF

This gist shows how to create a GIF screencast using only free OS X tools: QuickTime, ffmpeg, and gifsicle.

Instructions

To capture the video (filesize: 19MB), using the free "QuickTime Player" application:

peterhurford

1.) If I have a data.frame df <- data.frame(a = c(1, 2, 3), b = c(4, 5, 6), c(7, 8, 9))...

1a.) How do I select the c(4, 5, 6)?

1b.) How do I select the 1?

1c.) How do I select the 5?

1d.) What is df[, 3]?

pavlov99

// Based on following links:
// http://andrew.hedges.name/experiments/haversine/
// http://www.movable-type.co.uk/scripts/latlong.html
df
  .withColumn("a", pow(sin(toRadians($"destination_latitude" - $"origin_latitude") / 2), 2) + cos(toRadians($"origin_latitude")) * cos(toRadians($"destination_latitude")) * pow(sin(toRadians($"destination_longitude" - $"origin_longitude") / 2), 2))
  .withColumn("distance", atan2(sqrt($"a"), sqrt(-$"a" + 1)) * 2 * 6371)

>>>
+--------------+-------------------+-------------+----------------+---------------+----------------+--------------------+---------------------+--------------------+------------------+
|origin_airport|destination_airport|  origin_city|destination_city|origin_latitude|origin_longitude|destination_latitude|destination_longitude|                   a|          distance|