"#### 1. Import the numpy package under the name `np` (★☆☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "6c52078e",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "118ded29",
"metadata": {},
"source": [
"#### 2. Print the numpy version and the configuration (★☆☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "023a2c52",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "172b913a",
"metadata": {},
"source": [
"#### 3. Create a null vector of size 10 (★☆☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "df54025a",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "95ee9e07",
"metadata": {},
"source": [
"#### 4. How to find the memory size of any array (★☆☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "5c5b0950",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "45fca154",
"metadata": {},
"source": [
"#### 5. How to get the documentation of the numpy add function from the command line? (★☆☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "fcb1248a",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "674e8019",
"metadata": {},
"source": [
"#### 6. Create a null vector of size 10 but the fifth value which is 1 (★☆☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "452df2a7",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "7685e337",
"metadata": {},
"source": [
"#### 7. Create a vector with values ranging from 10 to 49 (★☆☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "10847d11",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "54c913ba",
"metadata": {},
"source": [
"#### 8. Reverse a vector (first element becomes last) (★☆☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "34722e83",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "8e72fd08",
"metadata": {},
"source": [
"#### 9. Create a 3x3 matrix with values ranging from 0 to 8 (★☆☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "e18eef56",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "088424fc",
"metadata": {},
"source": [
"#### 10. Find indices of non-zero elements from [1,2,0,0,4,0] (★☆☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "9a402d06",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "3f347de9",
"metadata": {},
"source": [
"#### 11. Create a 3x3 identity matrix (★☆☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "e38459c2",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "24e98f25",
"metadata": {},
"source": [
"#### 12. Create a 3x3x3 array with random values (★☆☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "94752bb3",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "7cbca2cc",
"metadata": {},
"source": [
"#### 13. Create a 10x10 array with random values and find the minimum and maximum values (★☆☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "c0643b1f",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "6cab4cbb",
"metadata": {},
"source": [
"#### 14. Create a random vector of size 30 and find the mean value (★☆☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "e922a524",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "72053be8",
"metadata": {},
"source": [
"#### 15. Create a 2d array with 1 on the border and 0 inside (★☆☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "6bc84dfe",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "86b0206b",
"metadata": {},
"source": [
"#### 16. How to add a border (filled with 0's) around an existing array? (★☆☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "41e66e3e",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "98a45574",
"metadata": {},
"source": [
"#### 17. What is the result of the following expression? (★☆☆)\n",
"```python\n",
"0 * np.nan\n",
"np.nan == np.nan\n",
"np.inf > np.nan\n",
"np.nan - np.nan\n",
"np.nan in set([np.nan])\n",
"0.3 == 3 * 0.1\n",
"```"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "7eb533d5",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "1486619a",
"metadata": {},
"source": [
"#### 18. Create a 5x5 matrix with values 1,2,3,4 just below the diagonal (★☆☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "2b9fb59c",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "319287fd",
"metadata": {},
"source": [
"#### 19. Create a 8x8 matrix and fill it with a checkerboard pattern (★☆☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "299f5e60",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "fb1686ed",
"metadata": {},
"source": [
"#### 20. Consider a (6,7,8) shape array, what is the index (x,y,z) of the 100th element? (★☆☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "22888cc4",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "137ea278",
"metadata": {},
"source": [
"#### 21. Create a checkerboard 8x8 matrix using the tile function (★☆☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "9cb81fe1",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "9319f5a1",
"metadata": {},
"source": [
"#### 22. Normalize a 5x5 random matrix (★☆☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "fcdc0459",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "f1902fef",
"metadata": {},
"source": [
"#### 23. Create a custom dtype that describes a color as four unsigned bytes (RGBA) (★☆☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "7445cb2d",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "3f34bd2a",
"metadata": {},
"source": [
"#### 24. Multiply a 5x3 matrix by a 3x2 matrix (real matrix product) (★☆☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "ec8bd6da",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "b1919ba3",
"metadata": {},
"source": [
"#### 25. Given a 1D array, negate all elements which are between 3 and 8, in place. (★☆☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "5b63b63b",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "fb1daa27",
"metadata": {},
"source": [
"#### 26. What is the output of the following script? (★☆☆)\n",
"```python\n",
"# Author: Jake VanderPlas\n",
"\n",
"print(sum(range(5),-1))\n",
"from numpy import *\n",
"print(sum(range(5),-1))\n",
"```"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "52a34d3d",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "89b7e7a7",
"metadata": {},
"source": [
"#### 27. Consider an integer vector Z, which of these expressions are legal? (★☆☆)\n",
"```python\n",
"Z**Z\n",
"2 << Z >> 2\n",
"Z <- Z\n",
"1j*Z\n",
"Z/1/1\n",
"Z<Z>Z\n",
"```"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "451181cf",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "8c7601c6",
"metadata": {},
"source": [
"#### 28. What are the result of the following expressions? (★☆☆)\n",
"```python\n",
"np.array(0) / np.array(0)\n",
"np.array(0) // np.array(0)\n",
"np.array([np.nan]).astype(int).astype(float)\n",
"```"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "52983a0b",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "06c9164d",
"metadata": {},
"source": [
"#### 29. How to round away from zero a float array ? (★☆☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "4cce0af8",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "52235994",
"metadata": {},
"source": [
"#### 30. How to find common values between two arrays? (★☆☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "27eff6b1",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "7e6f7d78",
"metadata": {},
"source": [
"#### 31. How to ignore all numpy warnings (not recommended)? (★☆☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "1bdde6e1",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "b001277e",
"metadata": {},
"source": [
"#### 32. Is the following expressions true? (★☆☆)\n",
"```python\n",
"np.sqrt(-1) == np.emath.sqrt(-1)\n",
"```"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "d8673bdf",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "b9a5ff84",
"metadata": {},
"source": [
"#### 33. How to get the dates of yesterday, today and tomorrow? (★☆☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "f33f9cc2",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "f8e96e58",
"metadata": {},
"source": [
"#### 34. How to get all the dates corresponding to the month of July 2016? (★★☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "3927a8e8",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "557c163e",
"metadata": {},
"source": [
"#### 35. How to compute ((A+B)*(-A/2)) in place (without copy)? (★★☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "3c2f59ac",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "14c05852",
"metadata": {},
"source": [
"#### 36. Extract the integer part of a random array of positive numbers using 4 different methods (★★☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "8b7d2937",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "003b8721",
"metadata": {},
"source": [
"#### 37. Create a 5x5 matrix with row values ranging from 0 to 4 (★★☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "63c75db0",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "8e71dc21",
"metadata": {},
"source": [
"#### 38. Consider a generator function that generates 10 integers and use it to build an array (★☆☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "f6aefd94",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "b7f03449",
"metadata": {},
"source": [
"#### 39. Create a vector of size 10 with values ranging from 0 to 1, both excluded (★★☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "a27cd904",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "043156c5",
"metadata": {},
"source": [
"#### 40. Create a random vector of size 10 and sort it (★★☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "6ae5eb58",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "4f7e8f3f",
"metadata": {},
"source": [
"#### 41. How to sum a small array faster than np.sum? (★★☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "88790af3",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "13d1ca52",
"metadata": {},
"source": [
"#### 42. Consider two random array A and B, check if they are equal (★★☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "ca6dd579",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "cf7cca6d",
"metadata": {},
"source": [
"#### 43. Make an array immutable (read-only) (★★☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "cbbb8917",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "37b0828f",
"metadata": {},
"source": [
"#### 44. Consider a random 10x2 matrix representing cartesian coordinates, convert them to polar coordinates (★★☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "a89969af",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "b7d7dd80",
"metadata": {},
"source": [
"#### 45. Create random vector of size 10 and replace the maximum value by 0 (★★☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "8403a440",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "b47e5837",
"metadata": {},
"source": [
"#### 46. Create a structured array with `x` and `y` coordinates covering the [0,1]x[0,1] area (★★☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "42c72e94",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "8c7946ee",
"metadata": {},
"source": [
"#### 47. Given two arrays, X and Y, construct the Cauchy matrix C (Cij =1/(xi - yj)) (★★☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "26b93f06",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "3e898e5f",
"metadata": {},
"source": [
"#### 48. Print the minimum and maximum representable value for each numpy scalar type (★★☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "afd1ae18",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "6fe6133b",
"metadata": {},
"source": [
"#### 49. How to print all the values of an array? (★★☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "5764ec92",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "7ee2dacc",
"metadata": {},
"source": [
"#### 50. How to find the closest value (to a given scalar) in a vector? (★★☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "742518ef",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "cfeda6ba",
"metadata": {},
"source": [
"#### 51. Create a structured array representing a position (x,y) and a color (r,g,b) (★★☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "9fcbd031",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "b97e75b5",
"metadata": {},
"source": [
"#### 52. Consider a random vector with shape (100,2) representing coordinates, find point by point distances (★★☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "c58a45b6",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "291e0bb9",
"metadata": {},
"source": [
"#### 53. How to convert a float (32 bits) array into an integer (32 bits) in place?"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "2f3e6c00",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "1e305e92",
"metadata": {},
"source": [
"#### 54. How to read the following file? (★★☆)\n",
"```\n",
"1, 2, 3, 4, 5\n",
"6, , , 7, 8\n",
" , , 9,10,11\n",
"```"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "753024cb",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "94a8ad69",
"metadata": {},
"source": [
"#### 55. What is the equivalent of enumerate for numpy arrays? (★★☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "ae45249f",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "72b340c9",
"metadata": {},
"source": [
"#### 56. Generate a generic 2D Gaussian-like array (★★☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "a80e5c9b",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "86550d61",
"metadata": {},
"source": [
"#### 57. How to randomly place p elements in a 2D array? (★★☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "db9f2582",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "153f8cfa",
"metadata": {},
"source": [
"#### 58. Subtract the mean of each row of a matrix (★★☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "8301cb12",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "f4038090",
"metadata": {},
"source": [
"#### 59. How to sort an array by the nth column? (★★☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "eb5745df",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "20d2a462",
"metadata": {},
"source": [
"#### 60. How to tell if a given 2D array has null columns? (★★☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "b92b7316",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "bb2aa49b",
"metadata": {},
"source": [
"#### 61. Find the nearest value from a given value in an array (★★☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "8b62e59c",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "1a950e1a",
"metadata": {},
"source": [
"#### 62. Considering two arrays with shape (1,3) and (3,1), how to compute their sum using an iterator? (★★☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "cad1d01b",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "165b3a20",
"metadata": {},
"source": [
"#### 63. Create an array class that has a name attribute (★★☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "666bf983",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "87f85b12",
"metadata": {},
"source": [
"#### 64. Consider a given vector, how to add 1 to each element indexed by a second vector (be careful with repeated indices)? (★★★)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "03ee4c88",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "1cda27c4",
"metadata": {},
"source": [
"#### 65. How to accumulate elements of a vector (X) to an array (F) based on an index list (I)? (★★★)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "aee2c782",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "1db205db",
"metadata": {},
"source": [
"#### 66. Considering a (w,h,3) image of (dtype=ubyte), compute the number of unique colors (★★☆)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "43204f35",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "ebaf1222",
"metadata": {},
"source": [
"#### 67. Considering a four dimensions array, how to get sum over the last two axis at once? (★★★)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "aabbbab9",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "2dfb4033",
"metadata": {},
"source": [
"#### 68. Considering a one-dimensional vector D, how to compute means of subsets of D using a vector S of same size describing subset indices? (★★★)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "7a9c2287",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "7035c626",
"metadata": {},
"source": [
"#### 69. How to get the diagonal of a dot product? (★★★)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "f6af16c1",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "8f73f0e5",
"metadata": {},
"source": [
"#### 70. Consider the vector [1, 2, 3, 4, 5], how to build a new vector with 3 consecutive zeros interleaved between each value? (★★★)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "b0cabc11",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "bafaa79e",
"metadata": {},
"source": [
"#### 71. Consider an array of dimension (5,5,3), how to mulitply it by an array with dimensions (5,5)? (★★★)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "d441e30b",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "80a9ac82",
"metadata": {},
"source": [
"#### 72. How to swap two rows of an array? (★★★)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "1aee2791",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "5e53d68c",
"metadata": {},
"source": [
"#### 73. Consider a set of 10 triplets describing 10 triangles (with shared vertices), find the set of unique line segments composing all the triangles (★★★)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "2f975322",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "f85da603",
"metadata": {},
"source": [
"#### 74. Given a sorted array C that corresponds to a bincount, how to produce an array A such that np.bincount(A) == C? (★★★)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "8c476a73",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "a2330e6c",
"metadata": {},
"source": [
"#### 75. How to compute averages using a sliding window over an array? (★★★)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "35e5e9f5",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "87698de8",
"metadata": {},
"source": [
"#### 76. Consider a one-dimensional array Z, build a two-dimensional array whose first row is (Z[0],Z[1],Z[2]) and each subsequent row is shifted by 1 (last row should be (Z[-3],Z[-2],Z[-1]) (★★★)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "753763ed",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "b8417b15",
"metadata": {},
"source": [
"#### 77. How to negate a boolean, or to change the sign of a float inplace? (★★★)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "3cad31b2",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "37a49831",
"metadata": {},
"source": [
"#### 78. Consider 2 sets of points P0,P1 describing lines (2d) and a point p, how to compute distance from p to each line i (P0[i],P1[i])? (★★★)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "df95dce8",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "f5ae032f",
"metadata": {},
"source": [
"#### 79. Consider 2 sets of points P0,P1 describing lines (2d) and a set of points P, how to compute distance from each point j (P[j]) to each line i (P0[i],P1[i])? (★★★)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "f5ae2e9b",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "6bc35ba2",
"metadata": {},
"source": [
"#### 80. Consider an arbitrary array, write a function that extract a subpart with a fixed shape and centered on a given element (pad with a `fill` value when necessary) (★★★)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "2ad8db75",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "d17818f7",
"metadata": {},
"source": [
"#### 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]]? (★★★)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "97deb72f",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "67f526e6",
"metadata": {},
"source": [
"#### 82. Compute a matrix rank (★★★)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "d70bed5b",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "0a3fb55f",
"metadata": {},
"source": [
"#### 83. How to find the most frequent value in an array?"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "b0647d07",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "cb0ac341",
"metadata": {},
"source": [
"#### 84. Extract all the contiguous 3x3 blocks from a random 10x10 matrix (★★★)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "91798923",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "c2a9da0d",
"metadata": {},
"source": [
"#### 85. Create a 2D array subclass such that Z[i,j] == Z[j,i] (★★★)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "f9b027ff",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "718ac868",
"metadata": {},
"source": [
"#### 86. Consider a set of p matrices with 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)) (★★★)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "4de05217",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "a6eda6f8",
"metadata": {},
"source": [
"#### 87. Consider a 16x16 array, how to get the block-sum (block size is 4x4)? (★★★)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "286b8db5",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "625aa611",
"metadata": {},
"source": [
"#### 88. How to implement the Game of Life using numpy arrays? (★★★)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "a01c1ff2",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "ca3dde4a",
"metadata": {},
"source": [
"#### 89. How to get the n largest values of an array (★★★)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "5d14148c",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "e233805e",
"metadata": {},
"source": [
"#### 90. Given an arbitrary number of vectors, build the cartesian product (every combinations of every item) (★★★)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "17638e13",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "c163f115",
"metadata": {},
"source": [
"#### 91. How to create a record array from a regular array? (★★★)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "da402514",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "049c006e",
"metadata": {},
"source": [
"#### 92. Consider a large vector Z, compute Z to the power of 3 using 3 different methods (★★★)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "96ce278a",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "6e652635",
"metadata": {},
"source": [
"#### 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? (★★★)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "f429d6d4",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "33c4755d",
"metadata": {},
"source": [
"#### 94. Considering a 10x3 matrix, extract rows with unequal values (e.g. [2,2,3]) (★★★)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "29507586",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "c9fe158d",
"metadata": {},
"source": [
"#### 95. Convert a vector of ints into a matrix binary representation (★★★)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "58209fb7",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "f60086c9",
"metadata": {},
"source": [
"#### 96. Given a two dimensional array, how to extract unique rows? (★★★)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "787b6e4c",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "0f5e1299",
"metadata": {},
"source": [
"#### 97. Considering 2 vectors A & B, write the einsum equivalent of inner, outer, sum, and mul function (★★★)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "cd2a8214",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "a04dd898",
"metadata": {},
"source": [
"#### 98. Considering a path described by two vectors (X,Y), how to sample it using equidistant samples (★★★)?"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "12d9c30f",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "b45bf2ae",
"metadata": {},
"source": [
"#### 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. (★★★)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "f4179f4a",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "d92b6592",
"metadata": {},
"source": [
"#### 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). (★★★)"
#### 1. Import the numpy package under the name `np` (★☆☆)
%% Cell type:code id:6c52078e tags:
```
```
%% Cell type:markdown id:118ded29 tags:
#### 2. Print the numpy version and the configuration (★☆☆)
%% Cell type:code id:023a2c52 tags:
```
```
%% Cell type:markdown id:172b913a tags:
#### 3. Create a null vector of size 10 (★☆☆)
%% Cell type:code id:df54025a tags:
```
```
%% Cell type:markdown id:95ee9e07 tags:
#### 4. How to find the memory size of any array (★☆☆)
%% Cell type:code id:5c5b0950 tags:
```
```
%% Cell type:markdown id:45fca154 tags:
#### 5. How to get the documentation of the numpy add function from the command line? (★☆☆)
%% Cell type:code id:fcb1248a tags:
```
```
%% Cell type:markdown id:674e8019 tags:
#### 6. Create a null vector of size 10 but the fifth value which is 1 (★☆☆)
%% Cell type:code id:452df2a7 tags:
```
```
%% Cell type:markdown id:7685e337 tags:
#### 7. Create a vector with values ranging from 10 to 49 (★☆☆)
%% Cell type:code id:10847d11 tags:
```
```
%% Cell type:markdown id:54c913ba tags:
#### 8. Reverse a vector (first element becomes last) (★☆☆)
%% Cell type:code id:34722e83 tags:
```
```
%% Cell type:markdown id:8e72fd08 tags:
#### 9. Create a 3x3 matrix with values ranging from 0 to 8 (★☆☆)
%% Cell type:code id:e18eef56 tags:
```
```
%% Cell type:markdown id:088424fc tags:
#### 10. Find indices of non-zero elements from [1,2,0,0,4,0] (★☆☆)
%% Cell type:code id:9a402d06 tags:
```
```
%% Cell type:markdown id:3f347de9 tags:
#### 11. Create a 3x3 identity matrix (★☆☆)
%% Cell type:code id:e38459c2 tags:
```
```
%% Cell type:markdown id:24e98f25 tags:
#### 12. Create a 3x3x3 array with random values (★☆☆)
%% Cell type:code id:94752bb3 tags:
```
```
%% Cell type:markdown id:7cbca2cc tags:
#### 13. Create a 10x10 array with random values and find the minimum and maximum values (★☆☆)
%% Cell type:code id:c0643b1f tags:
```
```
%% Cell type:markdown id:6cab4cbb tags:
#### 14. Create a random vector of size 30 and find the mean value (★☆☆)
%% Cell type:code id:e922a524 tags:
```
```
%% Cell type:markdown id:72053be8 tags:
#### 15. Create a 2d array with 1 on the border and 0 inside (★☆☆)
%% Cell type:code id:6bc84dfe tags:
```
```
%% Cell type:markdown id:86b0206b tags:
#### 16. How to add a border (filled with 0's) around an existing array? (★☆☆)
%% Cell type:code id:41e66e3e tags:
```
```
%% Cell type:markdown id:98a45574 tags:
#### 17. What is the result of the following expression? (★☆☆)
```python
0 * np.nan
np.nan == np.nan
np.inf > np.nan
np.nan - np.nan
np.nan in set([np.nan])
0.3 == 3 * 0.1
```
%% Cell type:code id:7eb533d5 tags:
```
```
%% Cell type:markdown id:1486619a tags:
#### 18. Create a 5x5 matrix with values 1,2,3,4 just below the diagonal (★☆☆)
%% Cell type:code id:2b9fb59c tags:
```
```
%% Cell type:markdown id:319287fd tags:
#### 19. Create a 8x8 matrix and fill it with a checkerboard pattern (★☆☆)
%% Cell type:code id:299f5e60 tags:
```
```
%% Cell type:markdown id:fb1686ed tags:
#### 20. Consider a (6,7,8) shape array, what is the index (x,y,z) of the 100th element? (★☆☆)
%% Cell type:code id:22888cc4 tags:
```
```
%% Cell type:markdown id:137ea278 tags:
#### 21. Create a checkerboard 8x8 matrix using the tile function (★☆☆)
%% Cell type:code id:9cb81fe1 tags:
```
```
%% Cell type:markdown id:9319f5a1 tags:
#### 22. Normalize a 5x5 random matrix (★☆☆)
%% Cell type:code id:fcdc0459 tags:
```
```
%% Cell type:markdown id:f1902fef tags:
#### 23. Create a custom dtype that describes a color as four unsigned bytes (RGBA) (★☆☆)
%% Cell type:code id:7445cb2d tags:
```
```
%% Cell type:markdown id:3f34bd2a tags:
#### 24. Multiply a 5x3 matrix by a 3x2 matrix (real matrix product) (★☆☆)
%% Cell type:code id:ec8bd6da tags:
```
```
%% Cell type:markdown id:b1919ba3 tags:
#### 25. Given a 1D array, negate all elements which are between 3 and 8, in place. (★☆☆)
%% Cell type:code id:5b63b63b tags:
```
```
%% Cell type:markdown id:fb1daa27 tags:
#### 26. What is the output of the following script? (★☆☆)
```python
# Author: Jake VanderPlas
print(sum(range(5),-1))
from numpy import *
print(sum(range(5),-1))
```
%% Cell type:code id:52a34d3d tags:
```
```
%% Cell type:markdown id:89b7e7a7 tags:
#### 27. Consider an integer vector Z, which of these expressions are legal? (★☆☆)
```python
Z**Z
2 <<Z>> 2
Z <- Z
1j*Z
Z/1/1
Z<Z>Z
```
%% Cell type:code id:451181cf tags:
```
```
%% Cell type:markdown id:8c7601c6 tags:
#### 28. What are the result of the following expressions? (★☆☆)
```python
np.array(0) / np.array(0)
np.array(0) // np.array(0)
np.array([np.nan]).astype(int).astype(float)
```
%% Cell type:code id:52983a0b tags:
```
```
%% Cell type:markdown id:06c9164d tags:
#### 29. How to round away from zero a float array ? (★☆☆)
%% Cell type:code id:4cce0af8 tags:
```
```
%% Cell type:markdown id:52235994 tags:
#### 30. How to find common values between two arrays? (★☆☆)
%% Cell type:code id:27eff6b1 tags:
```
```
%% Cell type:markdown id:7e6f7d78 tags:
#### 31. How to ignore all numpy warnings (not recommended)? (★☆☆)
%% Cell type:code id:1bdde6e1 tags:
```
```
%% Cell type:markdown id:b001277e tags:
#### 32. Is the following expressions true? (★☆☆)
```python
np.sqrt(-1) == np.emath.sqrt(-1)
```
%% Cell type:code id:d8673bdf tags:
```
```
%% Cell type:markdown id:b9a5ff84 tags:
#### 33. How to get the dates of yesterday, today and tomorrow? (★☆☆)
%% Cell type:code id:f33f9cc2 tags:
```
```
%% Cell type:markdown id:f8e96e58 tags:
#### 34. How to get all the dates corresponding to the month of July 2016? (★★☆)
%% Cell type:code id:3927a8e8 tags:
```
```
%% Cell type:markdown id:557c163e tags:
#### 35. How to compute ((A+B)*(-A/2)) in place (without copy)? (★★☆)
%% Cell type:code id:3c2f59ac tags:
```
```
%% Cell type:markdown id:14c05852 tags:
#### 36. Extract the integer part of a random array of positive numbers using 4 different methods (★★☆)
%% Cell type:code id:8b7d2937 tags:
```
```
%% Cell type:markdown id:003b8721 tags:
#### 37. Create a 5x5 matrix with row values ranging from 0 to 4 (★★☆)
%% Cell type:code id:63c75db0 tags:
```
```
%% Cell type:markdown id:8e71dc21 tags:
#### 38. Consider a generator function that generates 10 integers and use it to build an array (★☆☆)
%% Cell type:code id:f6aefd94 tags:
```
```
%% Cell type:markdown id:b7f03449 tags:
#### 39. Create a vector of size 10 with values ranging from 0 to 1, both excluded (★★☆)
%% Cell type:code id:a27cd904 tags:
```
```
%% Cell type:markdown id:043156c5 tags:
#### 40. Create a random vector of size 10 and sort it (★★☆)
%% Cell type:code id:6ae5eb58 tags:
```
```
%% Cell type:markdown id:4f7e8f3f tags:
#### 41. How to sum a small array faster than np.sum? (★★☆)
%% Cell type:code id:88790af3 tags:
```
```
%% Cell type:markdown id:13d1ca52 tags:
#### 42. Consider two random array A and B, check if they are equal (★★☆)
%% Cell type:code id:ca6dd579 tags:
```
```
%% Cell type:markdown id:cf7cca6d tags:
#### 43. Make an array immutable (read-only) (★★☆)
%% Cell type:code id:cbbb8917 tags:
```
```
%% Cell type:markdown id:37b0828f tags:
#### 44. Consider a random 10x2 matrix representing cartesian coordinates, convert them to polar coordinates (★★☆)
%% Cell type:code id:a89969af tags:
```
```
%% Cell type:markdown id:b7d7dd80 tags:
#### 45. Create random vector of size 10 and replace the maximum value by 0 (★★☆)
%% Cell type:code id:8403a440 tags:
```
```
%% Cell type:markdown id:b47e5837 tags:
#### 46. Create a structured array with `x` and `y` coordinates covering the [0,1]x[0,1] area (★★☆)
%% Cell type:code id:42c72e94 tags:
```
```
%% Cell type:markdown id:8c7946ee tags:
#### 47. Given two arrays, X and Y, construct the Cauchy matrix C (Cij =1/(xi - yj)) (★★☆)
%% Cell type:code id:26b93f06 tags:
```
```
%% Cell type:markdown id:3e898e5f tags:
#### 48. Print the minimum and maximum representable value for each numpy scalar type (★★☆)
%% Cell type:code id:afd1ae18 tags:
```
```
%% Cell type:markdown id:6fe6133b tags:
#### 49. How to print all the values of an array? (★★☆)
%% Cell type:code id:5764ec92 tags:
```
```
%% Cell type:markdown id:7ee2dacc tags:
#### 50. How to find the closest value (to a given scalar) in a vector? (★★☆)
%% Cell type:code id:742518ef tags:
```
```
%% Cell type:markdown id:cfeda6ba tags:
#### 51. Create a structured array representing a position (x,y) and a color (r,g,b) (★★☆)
%% Cell type:code id:9fcbd031 tags:
```
```
%% Cell type:markdown id:b97e75b5 tags:
#### 52. Consider a random vector with shape (100,2) representing coordinates, find point by point distances (★★☆)
%% Cell type:code id:c58a45b6 tags:
```
```
%% Cell type:markdown id:291e0bb9 tags:
#### 53. How to convert a float (32 bits) array into an integer (32 bits) in place?
%% Cell type:code id:2f3e6c00 tags:
```
```
%% Cell type:markdown id:1e305e92 tags:
#### 54. How to read the following file? (★★☆)
```
1, 2, 3, 4, 5
6, , , 7, 8
, , 9,10,11
```
%% Cell type:code id:753024cb tags:
```
```
%% Cell type:markdown id:94a8ad69 tags:
#### 55. What is the equivalent of enumerate for numpy arrays? (★★☆)
%% Cell type:code id:ae45249f tags:
```
```
%% Cell type:markdown id:72b340c9 tags:
#### 56. Generate a generic 2D Gaussian-like array (★★☆)
%% Cell type:code id:a80e5c9b tags:
```
```
%% Cell type:markdown id:86550d61 tags:
#### 57. How to randomly place p elements in a 2D array? (★★☆)
%% Cell type:code id:db9f2582 tags:
```
```
%% Cell type:markdown id:153f8cfa tags:
#### 58. Subtract the mean of each row of a matrix (★★☆)
%% Cell type:code id:8301cb12 tags:
```
```
%% Cell type:markdown id:f4038090 tags:
#### 59. How to sort an array by the nth column? (★★☆)
%% Cell type:code id:eb5745df tags:
```
```
%% Cell type:markdown id:20d2a462 tags:
#### 60. How to tell if a given 2D array has null columns? (★★☆)
%% Cell type:code id:b92b7316 tags:
```
```
%% Cell type:markdown id:bb2aa49b tags:
#### 61. Find the nearest value from a given value in an array (★★☆)
%% Cell type:code id:8b62e59c tags:
```
```
%% Cell type:markdown id:1a950e1a tags:
#### 62. Considering two arrays with shape (1,3) and (3,1), how to compute their sum using an iterator? (★★☆)
%% Cell type:code id:cad1d01b tags:
```
```
%% Cell type:markdown id:165b3a20 tags:
#### 63. Create an array class that has a name attribute (★★☆)
%% Cell type:code id:666bf983 tags:
```
```
%% Cell type:markdown id:87f85b12 tags:
#### 64. Consider a given vector, how to add 1 to each element indexed by a second vector (be careful with repeated indices)? (★★★)
%% Cell type:code id:03ee4c88 tags:
```
```
%% Cell type:markdown id:1cda27c4 tags:
#### 65. How to accumulate elements of a vector (X) to an array (F) based on an index list (I)? (★★★)
%% Cell type:code id:aee2c782 tags:
```
```
%% Cell type:markdown id:1db205db tags:
#### 66. Considering a (w,h,3) image of (dtype=ubyte), compute the number of unique colors (★★☆)
%% Cell type:code id:43204f35 tags:
```
```
%% Cell type:markdown id:ebaf1222 tags:
#### 67. Considering a four dimensions array, how to get sum over the last two axis at once? (★★★)
%% Cell type:code id:aabbbab9 tags:
```
```
%% Cell type:markdown id:2dfb4033 tags:
#### 68. Considering a one-dimensional vector D, how to compute means of subsets of D using a vector S of same size describing subset indices? (★★★)
%% Cell type:code id:7a9c2287 tags:
```
```
%% Cell type:markdown id:7035c626 tags:
#### 69. How to get the diagonal of a dot product? (★★★)
%% Cell type:code id:f6af16c1 tags:
```
```
%% Cell type:markdown id:8f73f0e5 tags:
#### 70. Consider the vector [1, 2, 3, 4, 5], how to build a new vector with 3 consecutive zeros interleaved between each value? (★★★)
%% Cell type:code id:b0cabc11 tags:
```
```
%% Cell type:markdown id:bafaa79e tags:
#### 71. Consider an array of dimension (5,5,3), how to mulitply it by an array with dimensions (5,5)? (★★★)
%% Cell type:code id:d441e30b tags:
```
```
%% Cell type:markdown id:80a9ac82 tags:
#### 72. How to swap two rows of an array? (★★★)
%% Cell type:code id:1aee2791 tags:
```
```
%% Cell type:markdown id:5e53d68c tags:
#### 73. Consider a set of 10 triplets describing 10 triangles (with shared vertices), find the set of unique line segments composing all the triangles (★★★)
%% Cell type:code id:2f975322 tags:
```
```
%% Cell type:markdown id:f85da603 tags:
#### 74. Given a sorted array C that corresponds to a bincount, how to produce an array A such that np.bincount(A) == C? (★★★)
%% Cell type:code id:8c476a73 tags:
```
```
%% Cell type:markdown id:a2330e6c tags:
#### 75. How to compute averages using a sliding window over an array? (★★★)
%% Cell type:code id:35e5e9f5 tags:
```
```
%% Cell type:markdown id:87698de8 tags:
#### 76. Consider a one-dimensional array Z, build a two-dimensional array whose first row is (Z[0],Z[1],Z[2]) and each subsequent row is shifted by 1 (last row should be (Z[-3],Z[-2],Z[-1]) (★★★)
%% Cell type:code id:753763ed tags:
```
```
%% Cell type:markdown id:b8417b15 tags:
#### 77. How to negate a boolean, or to change the sign of a float inplace? (★★★)
%% Cell type:code id:3cad31b2 tags:
```
```
%% Cell type:markdown id:37a49831 tags:
#### 78. Consider 2 sets of points P0,P1 describing lines (2d) and a point p, how to compute distance from p to each line i (P0[i],P1[i])? (★★★)
%% Cell type:code id:df95dce8 tags:
```
```
%% Cell type:markdown id:f5ae032f tags:
#### 79. Consider 2 sets of points P0,P1 describing lines (2d) and a set of points P, how to compute distance from each point j (P[j]) to each line i (P0[i],P1[i])? (★★★)
%% Cell type:code id:f5ae2e9b tags:
```
```
%% Cell type:markdown id:6bc35ba2 tags:
#### 80. Consider an arbitrary array, write a function that extract a subpart with a fixed shape and centered on a given element (pad with a `fill` value when necessary) (★★★)
%% Cell type:code id:2ad8db75 tags:
```
```
%% Cell type:markdown id:d17818f7 tags:
#### 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]]? (★★★)
%% Cell type:code id:97deb72f tags:
```
```
%% Cell type:markdown id:67f526e6 tags:
#### 82. Compute a matrix rank (★★★)
%% Cell type:code id:d70bed5b tags:
```
```
%% Cell type:markdown id:0a3fb55f tags:
#### 83. How to find the most frequent value in an array?
%% Cell type:code id:b0647d07 tags:
```
```
%% Cell type:markdown id:cb0ac341 tags:
#### 84. Extract all the contiguous 3x3 blocks from a random 10x10 matrix (★★★)
%% Cell type:code id:91798923 tags:
```
```
%% Cell type:markdown id:c2a9da0d tags:
#### 85. Create a 2D array subclass such that Z[i,j] == Z[j,i] (★★★)
%% Cell type:code id:f9b027ff tags:
```
```
%% Cell type:markdown id:718ac868 tags:
#### 86. Consider a set of p matrices with 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)) (★★★)
%% Cell type:code id:4de05217 tags:
```
```
%% Cell type:markdown id:a6eda6f8 tags:
#### 87. Consider a 16x16 array, how to get the block-sum (block size is 4x4)? (★★★)
%% Cell type:code id:286b8db5 tags:
```
```
%% Cell type:markdown id:625aa611 tags:
#### 88. How to implement the Game of Life using numpy arrays? (★★★)
%% Cell type:code id:a01c1ff2 tags:
```
```
%% Cell type:markdown id:ca3dde4a tags:
#### 89. How to get the n largest values of an array (★★★)
%% Cell type:code id:5d14148c tags:
```
```
%% Cell type:markdown id:e233805e tags:
#### 90. Given an arbitrary number of vectors, build the cartesian product (every combinations of every item) (★★★)
%% Cell type:code id:17638e13 tags:
```
```
%% Cell type:markdown id:c163f115 tags:
#### 91. How to create a record array from a regular array? (★★★)
%% Cell type:code id:da402514 tags:
```
```
%% Cell type:markdown id:049c006e tags:
#### 92. Consider a large vector Z, compute Z to the power of 3 using 3 different methods (★★★)
%% Cell type:code id:96ce278a tags:
```
```
%% Cell type:markdown id:6e652635 tags:
#### 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? (★★★)
%% Cell type:code id:f429d6d4 tags:
```
```
%% Cell type:markdown id:33c4755d tags:
#### 94. Considering a 10x3 matrix, extract rows with unequal values (e.g. [2,2,3]) (★★★)
%% Cell type:code id:29507586 tags:
```
```
%% Cell type:markdown id:c9fe158d tags:
#### 95. Convert a vector of ints into a matrix binary representation (★★★)
%% Cell type:code id:58209fb7 tags:
```
```
%% Cell type:markdown id:f60086c9 tags:
#### 96. Given a two dimensional array, how to extract unique rows? (★★★)
%% Cell type:code id:787b6e4c tags:
```
```
%% Cell type:markdown id:0f5e1299 tags:
#### 97. Considering 2 vectors A & B, write the einsum equivalent of inner, outer, sum, and mul function (★★★)
%% Cell type:code id:cd2a8214 tags:
```
```
%% Cell type:markdown id:a04dd898 tags:
#### 98. Considering a path described by two vectors (X,Y), how to sample it using equidistant samples (★★★)?
%% Cell type:code id:12d9c30f tags:
```
```
%% Cell type:markdown id:b45bf2ae tags:
#### 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. (★★★)
%% Cell type:code id:f4179f4a tags:
```
```
%% Cell type:markdown id:d92b6592 tags:
#### 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). (★★★)
