#APLQuest
#APLQuest 2018-02: Write a function that, given a scalar real non-negative number, will return a two-element vector of the integer and fractional parts of the number (see apl.quest/2018/2/ to test your solution and view ours).

#APL #IntegerFractional #NumberDecomposition
APL Quest 2018-2: Number Splitting
Write a function that, given a scalar real non-negative number, will return a two-element vector of the integer and fractional parts of the number.
apl.quest
September 28, 2026 at 2:08 PM
#APLQuest 2013-02: Write a function that returns the percent (from 0 to 100) of passing (65 or higher) grades in a vector of grades (see apl.quest/2013/2/ to test your solution and view ours). #APL #DataAnalysis #Percentages
APL Quest 2013-2: Making The Grade
Write a function which returns the percent (from 0 to 100) of passing (65 or higher) grades in a vector of grades.
apl.quest
October 13, 2025 at 1:06 PM
#APLQuest 2013-06: Write a function that returns the magnitude of the range of a numeric array. (see apl.quest/2013/6/ to test your solution and view ours).

#APL #Statistics #RangeCalculation
APL Quest 2013-6: Home On The Range
Write a function which returns the magnitude of the range of a numeric array.
apl.quest
November 10, 2025 at 2:31 PM
#APLQuest 2015-05: Write a function that returns the population standard deviation of its numeric array right argument (see apl.quest/2015/5/ to test your solution and view ours).

#APL #Statistics #StatisticalAnalysis
APL Quest 2015-5: He's so mean, he has no standard deviation
Write a function that returns the population standard deviation of its numeric array right argument.
apl.quest
March 23, 2026 at 3:36 PM
#APLQuest 2013-09: Write a function that produces n month moving averages for a year's worth of data (see apl.quest/2013/9/ to test your solution and view ours). #APL #MovingAverage #TimeSeriesAnalysis
APL Quest 2013-9: It Is a Moving Experience
Write a function which produces n month moving averages for a year's worth of data.
apl.quest
December 1, 2025 at 2:04 PM
#APLQuest 2013-08: Write a function that produces a multiplication table (see apl.quest/2013/8/ to test your solution and view ours). #APL #MultiplicationTable #MatrixGeneration
APL Quest 2013-8: Go Forth And Multiply
Write a function which produces a multiplication table.
apl.quest
November 24, 2025 at 2:06 PM
#APLQuest 2013-10: Write a function that solves a set of linear equations (see apl.quest/2013/10/ to test your solution and view ours). #APL #LinearEquations #MatrixDivision
APL Quest 2013-10: Solution Salvation
Write a function which solves a set of linear equations.
apl.quest
December 8, 2025 at 2:01 PM
#APLQuest 2017-06: Write a function that takes a character vector as its right argument and k (the substring length) as its left argument and returns a vector of the k-mers of the original string (see apl.quest/2017/6/ to test your solution and view ours).

#APL #DNA #Bioinformatics
APL Quest 2017-6: k-mers
Write a function that takes a character vector as its right argument and k (the substring length) as its left argument and returns a vector of the k-mers of the original string.
apl.quest
August 17, 2026 at 1:17 PM
#APLQuest 2014-04: Write a function that removes extraneous (leading, trailing, and multiple) spaces from a character vector (see apl.quest/2014/4/ to test your solution and view ours). #APL #StringNormalization #WhitespaceHandling
APL Quest 2014-4: Space The Final Frontier
Write a function that removes extraneous (leading, trailing, and multiple) spaces from a character vector.
apl.quest
January 5, 2026 at 2:11 PM
#APLQuest 2013-07: Write a function that selects the floating point (non-integer) numbers from a numeric vector (see apl.quest/2013/7/ to test your solution and view ours). #APL #DataFiltering #FloatingPoint
APL Quest 2013-7: Float Your Boat
Write a function which selects the floating point (non-integer) numbers from a numeric vector.
apl.quest
November 17, 2025 at 2:03 PM
#APLQuest 2018-01: Write a function that, given a scalar or vector of skyscraper heights from closest to furthest, will return an integer representing the number of skyscrapers that can be seen (see apl.quest/2018/1/ to test your solution and view ours).

#APL #SkylineProblem #RunningMaximum
APL Quest 2018-1: Oh Say Can You See?
Write a function that, given a scalar or vector of skyscraper heights from closest to furthest, will return an integer representing the number of skyscrapers that can be seen.
apl.quest
September 21, 2026 at 1:58 PM
#APLQuest 2016-02: Write a function that takes a numeric vector as its right argument and returns the median of the array (see apl.quest/2016/2/ to test your solution and view ours). #APL #Statistics #Median
APL Quest 2016-2: Statistics - Median
Write a function that takes a numeric vector as its right argument and returns the median of the array.
apl.quest
May 11, 2026 at 1:13 PM
#APLQuest 2017-02: Write a function that takes an integer array and replaces all the odd numbers with the next greater even number (see apl.quest/2017/2/ to test your solution and view ours).

#APL #EvenNumbers #ArrayTransformation
APL Quest 2017-2: Good Evening
Write a function that takes an integer array and replaces all the odd numbers with the next greater even number.
apl.quest
July 20, 2026 at 1:16 PM
#APLQuest 2017-10: Write a function that will reshape a given array into the smallest square matrix that will contain all the elements of the argument, padding with additional elements if necessary (see apl.quest/2017/10/ to test your solution and view ours).

#APL #SquareMatrix #ArrayReshaping
APL Quest 2017-10: Squaring Off
Write a function that will reshape a given array into the smallest square matrix that will contain all the elements of the argument, padding with additional elements if necessary.
apl.quest
September 14, 2026 at 1:18 PM
#APLQuest 2014-09: Write a function that calculates the distance (in metres) that a projectile travels, given an initial velocity (in metres per second) and a trajectory in degrees (see apl.quest/2014/9/ to test your solution and view ours). #APL #Physics #Mathematics
APL Quest 2014-9: Going Ballistic
Write a function which calculates the distance (in meters) a projectile travels given an initial velocity in meters per second and a trajectory in degrees.
apl.quest
February 9, 2026 at 2:19 PM
Our #APLMonday series is changing! From this week, we will be posting questions from #APLQuest. This week's question is 2013-01: Write a function to produce a vector of the first n odd numbers (see apl.quest/2013/1/ to test your solution and view ours). #APL #OddNumbers #SequenceGeneration
APL Quest 2013-1: Seems a Bit Odd To Me
Write a function to produce a vector of the first n odd numbers.
apl.quest
October 6, 2025 at 1:12 PM
#APLQuest 2016-04: Write a function that takes vectors as its left and right arguments and returns them “meshed” into a single vector formed by alternately taking successive elements from each argument (see apl.quest/2016/4/ to test your solution and view ours). #APL #Vectors #Meshed
APL Quest 2016-4: Just Meshing Around
Write a function that takes vectors as its left and right arguments and returns them “meshed” into a single vector formed by alternately taking successive elements from each argument.
apl.quest
May 25, 2026 at 9:50 PM
#APLQuest 2017-07: Write a function that takes a character vector representing a DNA string and returns 4 integers of the number of occurrences for each of the symbols 'A', 'C', 'G', and 'T' respectively (see apl.quest/2017/7/). #APL #DNASequencing #FrequencyCounting
APL Quest 2017-7: Counting DNA Nucleotides
Write a function that takes a character vector representing a DNA string and returns 4 integers of the number of occurrences for each of the symbols 'A', 'C', 'G', and 'T' respectively.
apl.quest
August 24, 2026 at 2:59 PM
#APLQuest 2015-10: Write a function that takes an integer right argument representing the order of the Pascal's triangle to be created and returns a “nicely” formatted character matrix (see apl.quest/2015/10/ to test your solution and view ours).

#APL #PascalsTriangle #TextFormatting
APL Quest 2015-10: Blaise'ing a Trail
Write a function that takes an integer right argument representing the order of the Pascal's triangle to be created and returns a “nicely” formatted character matrix.
apl.quest
April 27, 2026 at 2:17 PM
#APLQuest 2014-07: Write a function that takes the diameters of the stationary and mobile circles and returns the number of revolutions the mobile must traverse until the tangent points meet again (see apl.quest/2014/7/ to test your solution and view ours). #APL #CircleGeometry #RotationalMotion
APL Quest 2014-7: Revolutionary Thinking
Write a function which takes the diameters of the stationary and mobile circles and returns the number of revolutions the mobile must traverse until the tangent points meet again.
apl.quest
January 26, 2026 at 2:53 PM
#APLQuest 2016-10: Write a function that takes as its right argument a vector of prices and as its left argument a numeric vector that indicates the number ordered and returns the total cost for the order (see apl.quest/2016/10/ to test your solution and view ours).

#APL #DotProduct #VectorMath
APL Quest 2016-10: Order Total
Write a function that takes as its right argument a vector of prices and as its left argument a numeric vector that indicates the number ordered and returns the total cost for the order.
apl.quest
July 6, 2026 at 1:17 PM
#APLQuest 2014-06: Write a function that takes an integer vector representing the sides of a number of dice and returns a 2 column matrix of the number of ways each possible total of the dice can be rolled (see apl.quest/2014/6/ to test your solution and view ours). #APL #Probability #Combinatorics
APL Quest 2014-6: Roll The Dice
Write a function that takes an integer vector representing the sides of a number of dice and returns a 2 column matrix of the number of ways each possible total of the dice can be rolled.
apl.quest
January 19, 2026 at 2:20 PM
#APLQuest 2017-09: Write a function that takes a character vector or scalar and returns a Boolean vector indicating anywhere an element is followed by an element of the same value (see apl.quest/2017/9/ to test your solution and view ours).

#APL #DuplicateDetection #AdjacentComparison
APL Quest 2017-9: Double Trouble
Write a function that takes a character vector or scalar and returns a Boolean vector indicating anywhere an element is followed by an element of the same value.
apl.quest
September 7, 2026 at 2:48 PM
#APLQuest 2017-08: Write a function that takes a Boolean vector or scalar and “turns off” all the 1s after the first 1 (see apl.quest/2017/8/ to test your solution and view ours).

#APL #BooleanVectors #FirstOccurrence
APL Quest 2017-8: Be the First 1
Write a function that takes a Boolean vector or scalar and “turns off” all the 1s after the first 1.
apl.quest
August 31, 2026 at 1:40 PM
#APLQuest 2017-05: Write a function that takes a string representing a nucleotide and returns a `1` if it is a valid DNA string, `0` otherwise (see apl.quest/2017/5/ to test your solution and view ours). #APL #DNA #StringValidation
APL Quest 2017-5: DNA?
Write a function that takes a string representing a nucleotide and returns a `1` if it is a valid DNA string, `0` otherwise.
apl.quest
August 10, 2026 at 1:22 PM