81.Consider an array Z = [1,2,3,4,5,6,7,8,9,10,11,12,13,14], how to generate an array R = [[1,2,3,4], [2,3,4,5], [3,4,5,6], …, [11,12,13,14]]
考慮一個數組Z = [1,2,3,4,5,6,7,8,9,10,11,12,13,14],如何生成一個數組R = [[1,2,3,4], [2,3,4,5], [3,4,5,6], …,[11,12,13,14]]? (提示: stride_tricks.as_strided)
82.Compute a matrix rank
計算一個矩陣的秩
83.How to find the most frequent value in an array
如何找到一個數組中出現頻率最高的值
84.Extract all the contiguous 3x3 blocks from a random 10x10 matrix
從一個10x10的矩陣中提取出連續的3x3區塊
85.Create a 2D array subclass such that Z[i,j] == Z[j,i]
創建一個滿足 Z[i,j] == Z[j,i]的子類
86.Consider a set of p matrices wich shape (n,n) and a set of p vectors with shape (n,1). How to compute the sum of of the p matrix products at once(result has shape (n,1))
考慮p個 nxn 矩陣和p個形狀爲(n,1)的向量，如何直接計算p個矩陣的乘積的和(答案的形狀是(n,1))
87.Consider a 16x16 array, how to get the block-sum (block size is 4x4)
對於一個16x16的數組，如何得到一個區域(block-sum)的和(區域大小爲4x4)
88.How to implement the Game of Life using numpy arrays
如何利用numpy數組實現Game of Life
89.How to get the n largest values of an array
如何找到一個數組的第n個最大值
numpy.random.shuffle()
numpy.random,shuffle(x)是進行原地洗牌，直接改變x的值，而無返回值。
對於多維度的array來說，只對第一維進行洗牌，比如一個 3×33×3 的array，只對行之間進行洗牌，而行內內容保持不變。
90.Given an arbitrary number of vectors, build the cartesian product (every combinations of every item)
給定任意個數向量，創建笛卡爾積(每一個元素的每一種組合)
91.How to create a record array from a regular array
如何從一個正常數組創建記錄數組(record array)
92.Consider a large vector Z, compute Z to the power of 3 using 3 different methods
考慮一個大向量Z, 用三種不同的方法計算它的立方
93.Consider two arrays A and B of shape (8,3) and (2,2). How to find rows of A that contain elements of each row of B regardless of the order of the elements in B
考慮兩個形狀分別爲(8,3) 和(2,2)的數組A和B. 如何在數組A中找到滿足包含B中元素的行？(不考慮B中每行元素順序)
94.Considering a 10x3 matrix, extract rows with unequal values
考慮一個10x3的矩陣，分解出有不全相同值的行
95.Convert a vector of ints into a matrix binary representation
將一個整數向量轉換爲matrix binary的表現形式
96.Given a two dimensional array, how to extract unique rows
給定一個二維數組，如何提取出唯一的(unique)行
97.Considering 2 vectors A & B, write the einsum equivalent of inner, outer, sum, and mul function
考慮兩個向量A和B，寫出用einsum等式對應的inner, outer, sum, mul函數
98.Considering a path described by two vectors (X,Y), how to sample it using equidistant samples
考慮一個由兩個向量描述的路徑(X,Y)，如何用等距樣例(equidistant samples)對其進行採樣(sample)
99.Given an integer n and a 2D array X, select from X the rows which can be interpreted as draws from a multinomial distribution with n degrees, i.e., the rows which only contain integers and which sum to n
給定一個整數n和一個2D數組X，從X中選出行，滿足n次多項式分佈，即行內只有整數且相加爲n
100.Compute bootstrapped 95% confidence intervals for the mean of a 1D array X，i.e. resample the elements of an array with replacement N times, compute the mean of each sample, and then compute percentiles over the means.
對於一個一維數組X，計算它boostrapped之後的95%置信區間的平均值
