From 25ac81b95b2ebbfa6df50eb411d15b33ee33c4ba Mon Sep 17 00:00:00 2001 From: Nicolas Rougier Date: Sun, 16 Aug 2015 19:55:47 +0200 Subject: [PATCH] Removed sections to ease numbering --- README.html | 67 +++-------------- README.ipynb | 208 ++++++++++++++++++++++++++++----------------------- README.rst | 179 ++++++++++++++++---------------------------- 3 files changed, 190 insertions(+), 264 deletions(-) diff --git a/README.html b/README.html index c7d6b17..aafa6dc 100644 --- a/README.html +++ b/README.html @@ -3,7 +3,7 @@ - + 100 numpy exercises @@ -27,17 +27,11 @@ is:

Here is what the page looks like so far: http://www.labri.fr/perso/nrougier/teaching/numpy.100/index.html

-
-

Note

-

The level names came from an old-game (Dungeon Master)

-

Repository is at: https://github.com/rougier/numpy-100

The corresponding IPython notebook is available from the github repo, thanks to the rst2ipynb conversion tool by Valentin Haenel

Thanks to Michiaki Ariga, there is now a Julia version.

-
-

Neophyte

  1. Import the numpy package under the name np

    @@ -94,16 +88,13 @@ from the github repo, thanks to the Create a 3x3x3 array with random values
    
+
    
 
     Z = np.random.random((3,3,3))
 print Z
 
    
+
    2. -
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Novice

-

  1. Create a 8x8 matrix and fill it with a checkerboard pattern

     Z = np.zeros((8,8),dtype=int)
@@ -168,17 +159,14 @@ from the github repo, thanks to the Create a random vector of size 30 and find the mean value
    
+
    
 
     Z = np.random.random(30)
 m = Z.mean()
 print m
 
    
+
    2. -
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Apprentice

-

  1. Make an array immutable (read-only)

     Z = np.zeros(10)
@@ -267,18 +255,15 @@ point by point distances

  2. Find the nearest value from a given value in an array

    +
     Z = np.random.uniform(0,1,10)
 z = 0.5
 m = Z.flat[np.abs(Z - z).argmin()]
 print m
    +
    3. -
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-

Journeyman

-

  1. Consider the following file:

     1,2,3,4,5
@@ -375,6 +360,7 @@ dimensions (5,5) ?

  2. How to swap two rows of an array ?

    +
     # Author: Eelco Hoogendoorn
 
@@ -382,12 +368,8 @@ dimensions (5,5) ?
    
 A[[0,1]] = A[[1,0]]
 print A
    +
    3. -
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Craftsman

-

  1. 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])

    @@ -445,9 +427,6 @@ python -c "import numpy; numpy.info(num

  2. How to negate a boolean, or to change the sign of a float inplace ?

    -
    3. -
-
 # Author: Nathaniel J. Smith
 
@@ -457,14 +436,7 @@ python -c "import numpy; numpy.info(num
 Z = np.random.uniform(-1.0,1.0,100)
 np.negative(arr, out=arr)
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    -
  1. -
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Artisan

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    +

  1. Considering a 10x3 matrix, extract rows with unequal values (e.g. [2,2,3])

     # Author: Robert Kern
@@ -513,11 +485,6 @@ how to compute distance from each point j (P[j]) to each line i (P0[i],P1[i]) ?<
 Answer needed actually
    2. -
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Adept

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  1. 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)

    @@ -561,11 +528,6 @@ array R = [[1,2,3,4], [2,3,4,5], [3,4,5,6], ..., [11,12,13,14]] ?

    print R
    2. -
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Expert

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  1. 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 ?

    @@ -628,11 +590,6 @@ How to compute the sum of of the p matrix products at once ? (result has shape ( # and 2 and 1, to remain with a (n,1) vector.
    2. -
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Master

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  1. Given a two dimensional array, how to extract unique rows ?

    Note

    @@ -671,9 +628,5 @@ How to compute the sum of of the p matrix products at once ? (result has shape (
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-

Archmaster

-
- diff --git a/README.ipynb b/README.ipynb index f4ffe6f..2106c12 100644 --- a/README.ipynb +++ b/README.ipynb @@ -41,22 +41,7 @@ "metadata": {}, "source": [ "Here is what the page looks like so far:\n", - "\n" - ] - }, - { - "cell_type": "heading", - "level": 1, - "metadata": {}, - "source": [ - "Note" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "The level names came from an old-game (Dungeon Master)\n" + "\n" ] }, { @@ -85,14 +70,6 @@ "version](https://github.com/chezou/julia-100-exercises).\n" ] }, - { - "cell_type": "heading", - "level": 2, - "metadata": {}, - "source": [ - "Neophyte" - ] - }, { "cell_type": "markdown", "metadata": {}, @@ -205,7 +182,7 @@ "cell_type": "markdown", "metadata": {}, "source": [ - "Find indices of non-zero elements from [1,2,0,0,4,0]\n" + "Find indices of non-zero elements from \\[1,2,0,0,4,0\\]\n" ] }, { @@ -273,14 +250,6 @@ "metadata": {}, "outputs": [] }, - { - "cell_type": "heading", - "level": 2, - "metadata": {}, - "source": [ - "Novice" - ] - }, { "cell_type": "markdown", "metadata": {}, @@ -473,14 +442,6 @@ "metadata": {}, "outputs": [] }, - { - "cell_type": "heading", - "level": 2, - "metadata": {}, - "source": [ - "Apprentice" - ] - }, { "cell_type": "markdown", "metadata": {}, @@ -547,7 +508,7 @@ "metadata": {}, "source": [ "Create a structured array with `x` and `y` coordinates covering the\n", - "[0,1]x[0,1] area.\n" + "\\[0,1\\]x\\[0,1\\] area.\n" ] }, { @@ -698,14 +659,6 @@ "metadata": {}, "outputs": [] }, - { - "cell_type": "heading", - "level": 2, - "metadata": {}, - "source": [ - "Journeyman" - ] - }, { "cell_type": "markdown", "metadata": {}, @@ -880,7 +833,7 @@ "cell_type": "markdown", "metadata": {}, "source": [ - "Consider the vector [1, 2, 3, 4, 5], how to build a new vector with 3\n", + "Consider the vector \\[1, 2, 3, 4, 5\\], how to build a new vector with 3\n", "consecutive zeros interleaved between each value ?\n" ] }, @@ -941,21 +894,13 @@ "metadata": {}, "outputs": [] }, - { - "cell_type": "heading", - "level": 2, - "metadata": {}, - "source": [ - "Craftsman" - ] - }, { "cell_type": "markdown", "metadata": {}, "source": [ "Consider a one-dimensional array Z, build a two-dimensional array whose\n", - "first row is (Z[0],Z[1],Z[2]) and each subsequent row is shifted by 1\n", - "(last row should be (Z[-3],Z[-2],Z[-1])\n" + "first row is (Z\\[0\\],Z\\[1\\],Z\\[2\\]) and each subsequent row is shifted\n", + "by 1 (last row should be (Z\\[-3\\],Z\\[-2\\],Z\\[-1\\])\n" ] }, { @@ -1050,19 +995,49 @@ "outputs": [] }, { - "cell_type": "heading", - "level": 2, + "cell_type": "markdown", "metadata": {}, "source": [ - "Artisan" + "How to get the documentation of the numpy add function from the command\n", + "line ?\n" + ] + }, + { + "cell_type": "raw", + "metadata": {}, + "source": [ + "python -c \"import numpy; numpy.info(numpy.add)\"" ] }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "How to negate a boolean, or to change the sign of a float inplace ?\n" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Author: Nathaniel J. Smith\n", + "\n", + "Z = np.random.randint(0,2,100)\n", + "np.logical_not(arr, out=arr)\n", + "\n", + "Z = np.random.uniform(-1.0,1.0,100)\n", + "np.negative(arr, out=arr)" + ], + "language": "python", + "metadata": {}, + "outputs": [] + }, { "cell_type": "markdown", "metadata": {}, "source": [ "Considering a 10x3 matrix, extract rows with unequal values (e.g.\n", - "[2,2,3])\n" + "\\[2,2,3\\])\n" ] }, { @@ -1108,13 +1083,53 @@ "outputs": [] }, { - "cell_type": "heading", - "level": 2, + "cell_type": "markdown", "metadata": {}, "source": [ - "Adept" + "Consider 2 sets of points P0,P1 describing lines (2d) and a point p, how\n", + "to compute distance from p to each line i (P0\\[i\\],P1\\[i\\]) ?\n" ] }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "def distance(P0, P1, p):\n", + " T = P1 - P0\n", + " L = (T**2).sum(axis=1)\n", + " U = -((P0[:,0]-p[...,0])*T[:,0] + (P0[:,1]-p[...,1])*T[:,1]) / L\n", + " U = U.reshape(len(U),1)\n", + " D = P0 + U*T - p\n", + " return np.sqrt((D**2).sum(axis=1))\n", + "\n", + "P0 = np.random.uniform(-10,10,(10,2))\n", + "P1 = np.random.uniform(-10,10,(10,2))\n", + "p = np.random.uniform(-10,10,( 1,2))\n", + "print distance(P0, P1, p)" + ], + "language": "python", + "metadata": {}, + "outputs": [] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "Consider 2 sets of points P0,P1 describing lines (2d) and a set of\n", + "points P, how to compute distance from each point j (P\\[j\\]) to each\n", + "line i (P0\\[i\\],P1\\[i\\]) ?\n" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "Answer needed actually" + ], + "language": "python", + "metadata": {}, + "outputs": [] + }, { "cell_type": "markdown", "metadata": {}, @@ -1161,9 +1176,9 @@ "cell_type": "markdown", "metadata": {}, "source": [ - "Consider an array Z = [1,2,3,4,5,6,7,8,9,10,11,12,13,14], how to\n", - "generate an array R = [[1,2,3,4], [2,3,4,5], [3,4,5,6], ...,\n", - "[11,12,13,14]] ?\n" + "Consider an array Z = \\[1,2,3,4,5,6,7,8,9,10,11,12,13,14\\], how to\n", + "generate an array R = \\[\\[1,2,3,4\\], \\[2,3,4,5\\], \\[3,4,5,6\\], ...,\n", + "\\[11,12,13,14\\]\\] ?\n" ] }, { @@ -1180,14 +1195,6 @@ "metadata": {}, "outputs": [] }, - { - "cell_type": "heading", - "level": 2, - "metadata": {}, - "source": [ - "Expert" - ] - }, { "cell_type": "markdown", "metadata": {}, @@ -1242,7 +1249,7 @@ "cell_type": "markdown", "metadata": {}, "source": [ - "Create a 2D array subclass such that Z[i,j] == Z[j,i]\n" + "Create a 2D array subclass such that Z\\[i,j\\] == Z\\[j,i\\]\n" ] }, { @@ -1299,14 +1306,6 @@ "metadata": {}, "outputs": [] }, - { - "cell_type": "heading", - "level": 2, - "metadata": {}, - "source": [ - "Master" - ] - }, { "cell_type": "markdown", "metadata": {}, @@ -1316,7 +1315,7 @@ }, { "cell_type": "heading", - "level": 2, + "level": 1, "metadata": {}, "source": [ "Note" @@ -1348,12 +1347,37 @@ "outputs": [] }, { - "cell_type": "heading", - "level": 2, + "cell_type": "markdown", "metadata": {}, "source": [ - "Archmaster" + "How to implement the Game of Life using numpy arrays ?\n" ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Author: Nicolas Rougier\n", + "\n", + "def iterate(Z):\n", + " # Count neighbours\n", + " N = (Z[0:-2,0:-2] + Z[0:-2,1:-1] + Z[0:-2,2:] +\n", + " Z[1:-1,0:-2] + Z[1:-1,2:] +\n", + " Z[2: ,0:-2] + Z[2: ,1:-1] + Z[2: ,2:])\n", + "\n", + " # Apply rules\n", + " birth = (N==3) & (Z[1:-1,1:-1]==0)\n", + " survive = ((N==2) | (N==3)) & (Z[1:-1,1:-1]==1)\n", + " Z[...] = 0\n", + " Z[1:-1,1:-1][birth | survive] = 1\n", + " return Z\n", + "\n", + "Z = np.random.randint(0,2,(50,50))\n", + "for i in range(100): Z = iterate(Z)" + ], + "language": "python", + "metadata": {}, + "outputs": [] } ], "metadata": {} diff --git a/README.rst b/README.rst index 59c2c84..11d43ac 100644 --- a/README.rst +++ b/README.rst @@ -24,37 +24,20 @@ is: Here is what the page looks like so far: http://www.labri.fr/perso/nrougier/teaching/numpy.100/index.html -.. Note:: The level names came from an old-game (Dungeon Master) - Repository is at: https://github.com/rougier/numpy-100 -The corresponding `IPython notebook -`_ is available -from the github repo, thanks to the `rst2ipynb -`_ conversion tool by `Valentin Haenel -`_ - Thanks to Michiaki Ariga, there is now a `Julia version `_. -.. **Contents** -.. .. contents:: -.. :local: -.. :depth: 1 - - -Neophyte -======== - -1. Import the numpy package under the name ``np`` +#. Import the numpy package under the name ``np`` .. code-block:: python import numpy as np -2. Print the numpy version and the configuration. +#. Print the numpy version and the configuration. .. code-block:: python @@ -62,7 +45,7 @@ Neophyte np.__config__.show() -3. Create a null vector of size 10 +#. Create a null vector of size 10 .. code-block:: python @@ -70,7 +53,7 @@ Neophyte print Z -4. Create a null vector of size 10 but the fifth value which is 1 +#. Create a null vector of size 10 but the fifth value which is 1 .. code-block:: python @@ -79,7 +62,7 @@ Neophyte print Z -5. Create a vector with values ranging from 10 to 49 +#. Create a vector with values ranging from 10 to 49 .. code-block:: python @@ -87,7 +70,7 @@ Neophyte print Z -6. Create a 3x3 matrix with values ranging from 0 to 8 +#. Create a 3x3 matrix with values ranging from 0 to 8 .. code-block:: python @@ -95,7 +78,7 @@ Neophyte print Z -7. Find indices of non-zero elements from [1,2,0,0,4,0] +#. Find indices of non-zero elements from [1,2,0,0,4,0] .. code-block:: python @@ -103,7 +86,7 @@ Neophyte print nz -8. Create a 3x3 identity matrix +#. Create a 3x3 identity matrix .. code-block:: python @@ -111,7 +94,7 @@ Neophyte print Z -9. Create a 5x5 matrix with values 1,2,3,4 just below the diagonal +#. Create a 5x5 matrix with values 1,2,3,4 just below the diagonal .. code-block:: python @@ -119,18 +102,14 @@ Neophyte print Z -10. Create a 3x3x3 array with random values +#. Create a 3x3x3 array with random values .. code-block:: python Z = np.random.random((3,3,3)) print Z - -Novice -====== - -1. Create a 8x8 matrix and fill it with a checkerboard pattern +#. Create a 8x8 matrix and fill it with a checkerboard pattern .. code-block:: python @@ -140,7 +119,7 @@ Novice print Z -2. Create a 10x10 array with random values and find the minimum and maximum values +#. Create a 10x10 array with random values and find the minimum and maximum values .. code-block:: python @@ -149,7 +128,7 @@ Novice print Zmin, Zmax -3. Create a checkerboard 8x8 matrix using the tile function +#. Create a checkerboard 8x8 matrix using the tile function .. code-block:: python @@ -157,7 +136,7 @@ Novice print Z -4. Normalize a 5x5 random matrix (between 0 and 1) +#. Normalize a 5x5 random matrix (between 0 and 1) .. code-block:: python @@ -167,7 +146,7 @@ Novice print Z -5. Multiply a 5x3 matrix by a 3x2 matrix (real matrix product) +#. Multiply a 5x3 matrix by a 3x2 matrix (real matrix product) .. code-block:: python @@ -175,7 +154,7 @@ Novice print Z -6. Create a 5x5 matrix with row values ranging from 0 to 4 +#. Create a 5x5 matrix with row values ranging from 0 to 4 .. code-block:: python @@ -184,7 +163,7 @@ Novice print Z -7. Create a vector of size 10 with values ranging from 0 to 1, both excluded +#. Create a vector of size 10 with values ranging from 0 to 1, both excluded .. code-block:: python @@ -192,7 +171,7 @@ Novice print Z -8. Create a random vector of size 10 and sort it +#. Create a random vector of size 10 and sort it .. code-block:: python @@ -201,7 +180,7 @@ Novice print Z -9. Consider two random array A anb B, check if they are equal. +#. Consider two random array A anb B, check if they are equal. .. code-block:: python @@ -211,7 +190,7 @@ Novice print equal -10. Create a random vector of size 30 and find the mean value +#. Create a random vector of size 30 and find the mean value .. code-block:: python @@ -220,12 +199,7 @@ Novice print m - -Apprentice -========== - - -1. Make an array immutable (read-only) +#. Make an array immutable (read-only) .. code-block:: python @@ -234,7 +208,7 @@ Apprentice Z[0] = 1 -2. Consider a random 10x2 matrix representing cartesian coordinates, convert +#. Consider a random 10x2 matrix representing cartesian coordinates, convert them to polar coordinates .. code-block:: python @@ -247,7 +221,7 @@ Apprentice print T -3. Create random vector of size 10 and replace the maximum value by 0 +#. Create random vector of size 10 and replace the maximum value by 0 .. code-block:: python @@ -256,7 +230,7 @@ Apprentice print Z -4. Create a structured array with ``x`` and ``y`` coordinates covering the +#. Create a structured array with ``x`` and ``y`` coordinates covering the [0,1]x[0,1] area. .. code-block:: python @@ -267,7 +241,7 @@ Apprentice print Z -5. Print the minimum and maximum representable value for each numpy scalar type +#. Print the minimum and maximum representable value for each numpy scalar type .. code-block:: python @@ -280,7 +254,7 @@ Apprentice print np.finfo(dtype).eps -6. Create a structured array representing a position (x,y) and a color (r,g,b) +#. Create a structured array representing a position (x,y) and a color (r,g,b) .. code-block:: python @@ -292,7 +266,7 @@ Apprentice print Z -7. Consider a random vector with shape (100,2) representing coordinates, find +#. Consider a random vector with shape (100,2) representing coordinates, find point by point distances .. code-block:: python @@ -309,7 +283,7 @@ Apprentice print D -8. Generate a generic 2D Gaussian-like array +#. Generate a generic 2D Gaussian-like array .. code-block:: python @@ -320,7 +294,7 @@ Apprentice print G -9. How to tell if a given 2D array has null columns ? +#. How to tell if a given 2D array has null columns ? .. code-block:: python @@ -329,7 +303,7 @@ Apprentice Z = np.random.randint(0,3,(3,10)) print (~Z.any(axis=0)).any() -10. Find the nearest value from a given value in an array +#. Find the nearest value from a given value in an array .. code-block:: python @@ -339,10 +313,7 @@ Apprentice print m -Journeyman -========== - -1. Consider the following file:: +#. Consider the following file:: 1,2,3,4,5 6,,,7,8 @@ -355,7 +326,7 @@ Journeyman Z = np.genfromtxt("missing.dat", delimiter=",") -2. Consider a generator function that generates 10 integers and use it to build an +#. Consider a generator function that generates 10 integers and use it to build an array .. code-block:: python @@ -367,7 +338,7 @@ Journeyman print Z -3. Consider a given vector, how to add 1 to each element indexed by a second +#. Consider a given vector, how to add 1 to each element indexed by a second vector (be careful with repeated indices) ? .. code-block:: python @@ -380,7 +351,7 @@ Journeyman print Z -4. How to accumulate elements of a vector (X) to an array (F) based on an index +#. How to accumulate elements of a vector (X) to an array (F) based on an index list (I) ? .. code-block:: python @@ -393,7 +364,7 @@ Journeyman print F -5. Considering a (w,h,3) image of (dtype=ubyte), compute the number of unique +#. Considering a (w,h,3) image of (dtype=ubyte), compute the number of unique colors .. code-block:: python @@ -407,7 +378,7 @@ Journeyman print np.unique(I) -6. Considering a four dimensions array, how to get sum over the last two axis at once ? +#. Considering a four dimensions array, how to get sum over the last two axis at once ? .. code-block:: python @@ -416,7 +387,7 @@ Journeyman print -7. Considering a one-dimensional vector D, how to compute means of subsets of D +#. Considering a one-dimensional vector D, how to compute means of subsets of D using a vector S of same size describing subset indices ? @@ -432,7 +403,7 @@ Journeyman print D_means -8. Consider the vector [1, 2, 3, 4, 5], how to build a new vector with 3 +#. Consider the vector [1, 2, 3, 4, 5], how to build a new vector with 3 consecutive zeros interleaved between each value ? .. code-block:: python @@ -446,7 +417,7 @@ Journeyman print Z0 -9. Consider an array of dimension (5,5,3), how to mulitply it by an array with +#. Consider an array of dimension (5,5,3), how to mulitply it by an array with dimensions (5,5) ? .. code-block:: python @@ -456,7 +427,7 @@ Journeyman print A * B[:,:,None] -10. How to swap two rows of an array ? +#. How to swap two rows of an array ? .. code-block:: python @@ -468,10 +439,7 @@ Journeyman print A -Craftsman -========= - -1. Consider a one-dimensional array Z, build a two-dimensional array whose +#. 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]) @@ -488,7 +456,7 @@ Craftsman print Z -2. Consider a set of 10 triplets describing 10 triangles (with shared +#. Consider a set of 10 triplets describing 10 triangles (with shared vertices), find the set of unique line segments composing all the triangles. .. code-block:: python @@ -504,7 +472,7 @@ Craftsman print G -3. Given an array C that is a bincount, how to produce an array A such that +#. Given an array C that is a bincount, how to produce an array A such that np.bincount(A) == C ? .. code-block:: python @@ -515,7 +483,7 @@ Craftsman A = np.repeat(np.arange(len(C)), C) print A -4. How to compute averages using a sliding window over an array ? +#. How to compute averages using a sliding window over an array ? .. code-block:: python @@ -528,30 +496,26 @@ Craftsman Z = np.arange(20) print moving_average(Z, n=3) -5. How to get the documentation of the numpy add function from the command line ? +#. How to get the documentation of the numpy add function from the command line ? .. code-block:: bash python -c "import numpy; numpy.info(numpy.add)" -6. How to negate a boolean, or to change the sign of a float inplace ? +#. How to negate a boolean, or to change the sign of a float inplace ? - .. code-block:: python + .. code-block:: python - # Author: Nathaniel J. Smith + # Author: Nathaniel J. Smith - Z = np.random.randint(0,2,100) - np.logical_not(arr, out=arr) + Z = np.random.randint(0,2,100) + np.logical_not(arr, out=arr) - Z = np.random.uniform(-1.0,1.0,100) - np.negative(arr, out=arr) + Z = np.random.uniform(-1.0,1.0,100) + np.negative(arr, out=arr) -7. -Artisan -======= - -1. Considering a 10x3 matrix, extract rows with unequal values (e.g. [2,2,3]) +#. Considering a 10x3 matrix, extract rows with unequal values (e.g. [2,2,3]) .. code-block:: python @@ -563,7 +527,7 @@ Artisan print Z print U -2. Convert a vector of ints into a matrix binary representation. +#. Convert a vector of ints into a matrix binary representation. .. code-block:: python @@ -579,7 +543,7 @@ Artisan print np.unpackbits(I[:, np.newaxis], axis=1) -3. Consider 2 sets of points P0,P1 describing lines (2d) and a point p, how to +#. 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]) ? .. code-block:: python @@ -598,7 +562,7 @@ Artisan print distance(P0, P1, p) -4. Consider 2 sets of points P0,P1 describing lines (2d) and a set of points P, +#. 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]) ? .. code-block:: python @@ -606,11 +570,7 @@ Artisan Answer needed actually - -Adept -===== - -1. Consider an arbitrary array, write a function that extract a subpart with a +#. 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) @@ -645,7 +605,7 @@ Adept print R -2. Consider an array Z = [1,2,3,4,5,6,7,8,9,10,11,12,13,14], how to generate an +#. 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]] ? .. code-block:: python @@ -657,10 +617,7 @@ Adept print R -Expert -====== - -1. Consider two arrays A and B of shape (8,3) and (2,2). How to find rows of A +#. 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 ? @@ -676,7 +633,7 @@ Expert print rows -2. Extract all the contiguous 3x3 blocks from a random 10x10 matrix. +#. Extract all the contiguous 3x3 blocks from a random 10x10 matrix. .. code-block:: python @@ -690,7 +647,7 @@ Expert print C -3. Create a 2D array subclass such that Z[i,j] == Z[j,i] +#. Create a 2D array subclass such that Z[i,j] == Z[j,i] .. code-block:: python @@ -709,7 +666,7 @@ Expert S[2,3] = 42 print S -4. Consider a set of p matrices wich shape (n,n) and a set of p vectors with shape (n,1). +#. 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)) .. code-block:: python @@ -729,10 +686,7 @@ Expert # and 2 and 1, to remain with a (n,1) vector. -Master -====== - -1. Given a two dimensional array, how to extract unique rows ? +#. Given a two dimensional array, how to extract unique rows ? .. note:: See `stackoverflow `_ for explanations. @@ -746,7 +700,7 @@ Master uZ = Z[idx] print uZ -2. How to implement the Game of Life using numpy arrays ? +#. How to implement the Game of Life using numpy arrays ? .. code-block:: python @@ -767,8 +721,3 @@ Master Z = np.random.randint(0,2,(50,50)) for i in range(100): Z = iterate(Z) - - - -Archmaster -==========