Matlab / Octave Higher Order Functions - quasi-Functional Programming

higherOrderFunction.m

% Author: Caio Rodrigues
% Objective: Test higher order functions and anonymous functions.
% 
% Limitations: Doesn't support assignment in lambda function and also doens't support multiple lines.
% Other limitations are that functions cannot be stored in data structures or returned from functions.
%
octave:30> computeTable = @(xmin, dx, xmax, fn) [ (xmin:dx:xmax)'  (fn(xmin:dx:xmax))'] 
computeTable =

octave:15> computeTable(0.0, 0.1, 2.0, @(x)[2 * x + 1.0])
ans =

   0.00000   1.00000
   0.10000   1.20000
   0.20000   1.40000
   0.30000   1.60000
   0.40000   1.80000
   0.50000   2.00000
   0.60000   2.20000
   0.70000   2.40000
   0.80000   2.60000
   0.90000   2.80000
   1.00000   3.00000
   1.10000   3.20000
   1.20000   3.40000
   1.30000   3.60000
   1.40000   3.80000
   1.50000   4.00000
   1.60000   4.20000
   1.70000   4.40000
   1.80000   4.60000
   1.90000   4.80000
   2.00000   5.00000
   
octave:34> computeTable(0.0, 0.1, 2.0, @exp)
ans =

   0.00000   1.00000
   0.10000   1.10517
   0.20000   1.22140
   0.30000   1.34986
   0.40000   1.49182
   0.50000   1.64872
   0.60000   1.82212
   0.70000   2.01375
   0.80000   2.22554
   0.90000   2.45960
   1.00000   2.71828
   1.10000   3.00417
   1.20000   3.32012
   1.30000   3.66930
   1.40000   4.05520
   1.50000   4.48169
   1.60000   4.95303
   1.70000   5.47395
   1.80000   6.04965
   1.90000   6.68589
   2.00000   7.38906

   
octave:12> thunk = @() disp('Hello world')
thunk =

@() disp ('Hello world')

octave:13> thunk()
Hello world
octave:14> 


computeTableTrig = @(min, step, max, fn)[ (min:step:max)' (fn(pi / 180.0 * (min:step:max)))']
  
% Table with angles in degrees and sines  
octave:21> computeTableTrig(0.0, 15.0, 180.0, @sin)
ans =

     0.00000     0.00000
    15.00000     0.25882
    30.00000     0.50000
    45.00000     0.70711
    60.00000     0.86603
    75.00000     0.96593
    90.00000     1.00000
   105.00000     0.96593
   120.00000     0.86603
   135.00000     0.70711
   150.00000     0.50000
   165.00000     0.25882
   180.00000     0.00000
 
% Table with angles in degrees, radians and tan 
computeTableTrig2 = @(min, step, max, fn)[ (min:step:max)'  (pi / 180 * (min:step:max))' (fn(pi / 180.0 * (min:step:max)))']

octave:29> computeTableTrig2(0.0, 15.0, 180.0, @sin)
ans =

     0.00000     0.00000     0.00000
    15.00000     0.26180     0.25882
    30.00000     0.52360     0.50000
    45.00000     0.78540     0.70711
    60.00000     1.04720     0.86603
    75.00000     1.30900     0.96593
    90.00000     1.57080     1.00000
   105.00000     1.83260     0.96593
   120.00000     2.09440     0.86603
   135.00000     2.35619     0.70711
   150.00000     2.61799     0.50000
   165.00000     2.87979     0.25882
   180.00000     3.14159     0.00000