Question

I’m trying to design a Ruby script that will help with RC/RL circuit design by taking values of E24 series resistors and E12 and E6 series capacitors and inductors. Basically just cycling through each possible combination with the equation F = 1 / ( 2 * Pi * R * C ) [for the RC circuit for eg].

I’m not after efficiency here, just reliability. I need it to cycle through every single combination of the resistor array and capacitor/inductor array (never all 3) using the values for the equation above and if it is within plus/minus x% of a certain value to return which values in the array it used. I can nest 2 for loops to go through each combination, but I want it to not just return values within a tolerance but tell me which value is the closest (or exact).

Answer 1

This is a mild refactoring of your code:

# I noticed that your resistance array is just the same set of values
# repeated with factors from 1 to 1000000, so this would be more concise
# way of defining it (and less prone to typing errors):
RES_ARRAY = [*-1..5].map{ |e| 10 ** e }.map{ |factor|
             [ 10, 11, 12, 13, 15, 16, 18, 20,
               22, 24, 27, 30, 33, 36, 39, 43,
               47, 51, 56, 62, 68, 75, 82, 91 ].map{ |e| e * factor }
           }.reduce( :+ )

# Global variables should be used very rarely. Constants should be written IN UPCASE:
CAP_ARRAY, IND_ARRAY = [], []
BREAK_FREQ = 19 * ( 10 ** 3 )

# Whole words should be used whenever possible in the code:
TOLERANCE = 0.997

# Methods should be named in snake_case:
def make_array( j, arr )
  # Let us use #each_slice and #map insterad of % and << operators:
  arr.each_slice( j ).map( &:first ).map{ |e| e * 1e-9 }
end

def cap_test
  puts "RC Circuit Estimation"
  for i in 0...RES_ARRAY.size
    for j in 0...CAP_ARRAY.size
      n = 1 / ( 2 * Math::PI * RES_ARRAY[ i ] * CAP_ARRAY[ j ] )
      if n > BREAK_FREQ * TOLERANCE and n < BREAK_FREQ * ( 2 - TOLERANCE )
        diff = 100 - ( ( n - BREAK_FREQ ) / BREAK_FREQ ).abs
        puts "Resistor:  #{RES_ARRAY[ i ]} Ohms"
        puts "Capacitor: #{CAP_ARRAY[ j ].to_f} F"
        puts "Within #{diff}%"
        puts "---------------------"
      end
    end
  end
end

def ind_test
  puts "RL Circuit Estimation"
  for i in 0...RES_ARRAY.size
    for j in 0...IND_ARRAY.size
      n = RES_ARRAY[ i ] / ( 2 * Math::PI * IND_ARRAY[ j ] )
      if n > BREAK_FREQ * TOLERANCE and n < BREAK_FREQ * ( 2 - TOLERANCE )
        diff = ( 1 - ( ( n - BREAK_FREQ ) / BREAK_FREQ ).abs ) * 100
        puts "Resistor:  #{RES_ARRAY[ i ]} Ohms"
        puts "Inductor: #{IND_ARRAY[ j ].to_f} H"
        puts "Within #{diff}%"
        puts "---------------------"
      end
    end
  end
end

make_array 2, CAP_ARRAY
make_array 4, IND_ARRAY
cap_Test()
ind_Test()