updating DIRECTORY.md

Author: cclauss

DIRECTORY.md

@@ -87,7 +87,6 @@
   * [Count 1S Brian Kernighan Method](bit_manipulation/count_1s_brian_kernighan_method.py)
   * [Count Number Of One Bits](bit_manipulation/count_number_of_one_bits.py)
   * [Excess 3 Code](bit_manipulation/excess_3_code.py)
-  * [Fast Walsh Hadamard Transform](bit_manipulation/fast_walsh_hadamard_transform.py)
   * [Find Previous Power Of Two](bit_manipulation/find_previous_power_of_two.py)
   * [Find Unique Number](bit_manipulation/find_unique_number.py)
   * [Gray Code Sequence](bit_manipulation/gray_code_sequence.py)
@@ -252,7 +251,6 @@
     * [Basic Binary Tree](data_structures/binary_tree/basic_binary_tree.py)
     * [Binary Search Tree](data_structures/binary_tree/binary_search_tree.py)
     * [Binary Search Tree Recursive](data_structures/binary_tree/binary_search_tree_recursive.py)
-    * [Binary Tree Maximum Path Sum](data_structures/binary_tree/binary_tree_maximum_path_sum.py)
     * [Binary Tree Mirror](data_structures/binary_tree/binary_tree_mirror.py)
     * [Binary Tree Node Sum](data_structures/binary_tree/binary_tree_node_sum.py)
     * [Binary Tree Path Sum](data_structures/binary_tree/binary_tree_path_sum.py)
@@ -698,6 +696,8 @@
   * [Support Vector Machines](machine_learning/support_vector_machines.py)
   * [T Stochastic Neighbour Embedding](machine_learning/t_stochastic_neighbour_embedding.py)
   * [Word Frequency Functions](machine_learning/word_frequency_functions.py)
+  * [Xgboost Classifier](machine_learning/xgboost_classifier.py)
+  * [Xgboost Regressor](machine_learning/xgboost_regressor.py)
 
 ## [Maths](maths)
   * [Abs](maths/abs.py)
@@ -722,15 +722,12 @@
   * [Chebyshev Distance](maths/chebyshev_distance.py)
   * [Check Polygon](maths/check_polygon.py)
   * [Chinese Remainder Theorem](maths/chinese_remainder_theorem.py)
-  * [Cholesky Decomposition](maths/cholesky_decomposition.py)
   * [Chudnovsky Algorithm](maths/chudnovsky_algorithm.py)
   * [Collatz Sequence](maths/collatz_sequence.py)
   * [Combinations](maths/combinations.py)
   * [Continued Fraction](maths/continued_fraction.py)
-  * [Convolve 1D](maths/convolve_1d.py)
   * [Decimal Isolate](maths/decimal_isolate.py)
   * [Decimal To Fraction](maths/decimal_to_fraction.py)
-  * [Derangement](maths/derangement.py)
   * [Dodecahedron](maths/dodecahedron.py)
   * [Double Factorial](maths/double_factorial.py)
   * [Dual Number Automatic Differentiation](maths/dual_number_automatic_differentiation.py)
@@ -766,10 +763,8 @@
   * [Juggler Sequence](maths/juggler_sequence.py)
   * [Karatsuba](maths/karatsuba.py)
   * [Kth Lexicographic Permutation](maths/kth_lexicographic_permutation.py)
-  * [Laplace Transformation](maths/laplace_transformation.py)
   * [Largest Of Very Large Numbers](maths/largest_of_very_large_numbers.py)
   * [Least Common Multiple](maths/least_common_multiple.py)
-  * [Line Intersection](maths/line_intersection.py)
   * [Line Length](maths/line_length.py)
   * [Liouville Lambda](maths/liouville_lambda.py)
   * [Lucas Lehmer Primality Test](maths/lucas_lehmer_primality_test.py)
@@ -789,7 +784,6 @@
     * [Adams Bashforth](maths/numerical_analysis/adams_bashforth.py)
     * [Bisection](maths/numerical_analysis/bisection.py)
     * [Bisection 2](maths/numerical_analysis/bisection_2.py)
-    * [Brent Method](maths/numerical_analysis/brent_method.py)
     * [Integration By Simpson Approx](maths/numerical_analysis/integration_by_simpson_approx.py)
     * [Intersection](maths/numerical_analysis/intersection.py)
     * [Nevilles Method](maths/numerical_analysis/nevilles_method.py)
@@ -805,7 +799,6 @@
     * [Square Root](maths/numerical_analysis/square_root.py)
     * [Weierstrass Method](maths/numerical_analysis/weierstrass_method.py)
   * [Odd Sieve](maths/odd_sieve.py)
-  * [Pell Number](maths/pell_number.py)
   * [Perfect Cube](maths/perfect_cube.py)
   * [Perfect Number](maths/perfect_number.py)
   * [Perfect Square](maths/perfect_square.py)
@@ -839,9 +832,7 @@
     * [Harmonic](maths/series/harmonic.py)
     * [Harmonic Series](maths/series/harmonic_series.py)
     * [Hexagonal Numbers](maths/series/hexagonal_numbers.py)
-    * [Logarithmic Series](maths/series/logarithmic_series.py)
     * [P Series](maths/series/p_series.py)
-  * [Sieve Of Atkin](maths/sieve_of_atkin.py)
   * [Sieve Of Eratosthenes](maths/sieve_of_eratosthenes.py)
   * [Sigmoid](maths/sigmoid.py)
   * [Signum](maths/signum.py)
@@ -881,16 +872,12 @@
   * [Test Factorial](maths/test_factorial.py)
   * [Test Prime Check](maths/test_prime_check.py)
   * [Three Sum](maths/three_sum.py)
-  * [Tonelli Shanks](maths/tonelli_shanks.py)
-  * [Trailing Zeroes](maths/trailing_zeroes.py)
   * [Trapezoidal Rule](maths/trapezoidal_rule.py)
   * [Triplet Sum](maths/triplet_sum.py)
   * [Twin Prime](maths/twin_prime.py)
   * [Two Pointer](maths/two_pointer.py)
   * [Two Sum](maths/two_sum.py)
   * [Volume](maths/volume.py)
-  * [Weddles Rule](maths/weddles_rule.py)
-  * [Weighted Average](maths/weighted_average.py)
   * [Zellers Congruence](maths/zellers_congruence.py)
 
 ## [Matrix](matrix)
@@ -1370,7 +1357,6 @@
   * [Dutch National Flag Sort](sorts/dutch_national_flag_sort.py)
   * [Exchange Sort](sorts/exchange_sort.py)
   * [External Sort](sorts/external_sort.py)
-  * [Flash Sort](sorts/flash_sort.py)
   * [Gnome Sort](sorts/gnome_sort.py)
   * [Heap Sort](sorts/heap_sort.py)
   * [Insertion Sort](sorts/insertion_sort.py)