Module: Mathpack::IO

Defined in:
lib/mathpack/io.rb

Constant Summary collapse

@@next_stop = 
/[+*-\/() ]/
@@operators = 
%w{+ - / ** *}
@@delimiters = 
%w{, .}
@@numbers = 
%w{0 1 2 3 4 5 6 7 8 9}
@@math_constants = 
{ 'pi' => 'Math::PI' }
@@math_functions = 
{ 'ln(' => 'Math.log(', 'e**(' => 'Math.exp(', 'arctg(' => 'Math.atan(', 'arcsin(' => 'Math.asin(', 'arccos(' => 'Math.acos(', 'sin(' => 'Math.sin(', 'cos(' => 'Math.cos(', 'tg(' => 'Math.tan(', 'lg(' => 'Math.log10(' }

Class Method Summary collapse

Class Method Details

.count_diff(first_array, second_array) ⇒ Object 



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# File 'lib/mathpack/io.rb', line 100

def self.count_diff(first_array, second_array)
  if first_array.length == second_array.length
    diff = Array.new(first_array.length){ |i| (first_array[i] - second_array[i]).abs }
  elsif first_array.length == second_array.length * 2 - 1
    diff = Array.new(second_array.length) { |i| (first_array[2 * i] - second_array[i]).abs }
  else
    fail 'Arrays length mismatch'
  end
  diff.max
end

.is_valid_function?(function_string) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/mathpack/io.rb', line 40

def self.is_valid_function?(function_string)
  str = function_string.dup
  @@math_functions.values.each do |math_func|
    str.gsub!(math_func, '(')
  end
  str.delete!(' ')
  str.gsub!('x', '')
  (@@operators + @@delimiters + @@numbers).each do |sym|
    str.gsub!(sym, '')
  end
  brackets_stack = []
  str.each_char do |bracket|
    if brackets_stack.empty?
      brackets_stack << bracket
      next
    end
    if bracket.eql? '('
      brackets_stack << bracket
    else
      if brackets_stack.last.eql? '('
        brackets_stack.pop
      else
        brackets_stack << bracket
      end
    end
  end
  str.gsub!(/[\(\)]/, '')
  brackets_stack.empty? && str.empty?
end

.parse_function(string_function) ⇒ Object 



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# File 'lib/mathpack/io.rb', line 35

def self.parse_function(string_function)
  transformed_function = transform_string_function string_function
  produce_block(transformed_function) if is_valid_function?(transformed_function)
end

.print_table_function(params = {}) ⇒ Object 



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# File 'lib/mathpack/io.rb', line 11

def self.print_table_function(params = {})
  fail 'Arrays length dismatch' if params[:x].length != params[:y].length
  File.open(params[:filename]|| 'table_function.csv', 'w+') do |file|
    file.write("#{params[:labels][:x]};#{params[:labels][:y]}\n") if params[:labels] && params[:labels][:x] && params[:labels][:y]
    params[:x].each_index do |i|
      file.write("#{params[:x][i]};#{params[:y][i]}\n")
    end
  end
end

.produce_block(valid_function) ⇒ Object 



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# File 'lib/mathpack/io.rb', line 93

def self.produce_block(valid_function)
  valid_function.gsub!('x', 'var')
  valid_function.gsub!('evarp', 'exp')
  calculate = -> str { ->x { eval str.gsub('var', x.to_s) } }
  calculate.(valid_function)
end

.read_table_function(filename) ⇒ Object 



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# File 'lib/mathpack/io.rb', line 21

def self.read_table_function(filename)
  x = []
  y = []
  data = File.read(filename)
  rows = data.split("\n")
  rows.delete!(0) unless rows[0].split(';')[0].to_f
  rows.each do |row|
    parts = row.split(';')
    x << parts[0].to_f
    y << parts[1].to_f
  end
  { x: x, y: y}
end

.transform_string_function(function_string) ⇒ Object 



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# File 'lib/mathpack/io.rb', line 70

def self.transform_string_function(function_string)
  function = function_string.dup
  i_next = 0
  while i_next != function.length do
    i = function.index('^', i_next)
    break if i.nil?
    if function[i + 1].eql? '('
      function[i..i + 1] = '**('
    else
      i_next = function.index(@@next_stop, i)
      i_next = function.length unless i_next
      function[i...i_next] = '**('+ function[i + 1...i_next] + ')'
    end
  end
  @@math_functions.each do |key, value|
    function.gsub!(key, value)
  end
  @@math_constants.each do |key, value|
    function.gsub!(key, value)
  end
  function
end