Module: WavSpectrumAnalyzer::Common

Included in:
FFTApp, WaveLetApp
Defined in:
lib/wavspa/common.rb

Instance Method Summary collapse

Instance Method Details

#down_step(freq) ⇒ Object 



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# File 'lib/wavspa/common.rb', line 22

def down_step(freq)
  return (@logscale)? (freq / @grid_step): (freq - @grid_step)
end

#draw_freq_line(fb) ⇒ Object 



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# File 'lib/wavspa/common.rb', line 26

def draw_freq_line(fb)
  #
  # 低周波方向
  #
  frq = down_step(@basis_freq)
  loop {
    pos  = fpos(frq)
    break if pos >= @output_width

    fb.hline(pos, "#{frq.to_i}Hz") if pos >= 0
    frq = down_step(frq)
  }
 
  #
  # 高周波方向
  #
  frq = @basis_freq;
  loop {
    pos = fpos(frq)
    break if pos <= 0 

    fb.hline(pos, "#{frq.to_i}Hz") if pos < @output_width
    frq = up_step(frq)
  }
end

#draw_time_line(fb, wav, usize) ⇒ Object 



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# File 'lib/wavspa/common.rb', line 65

def draw_time_line(fb, wav, usize)
  tc = 0
  tm = 0
  n  = (wav.data_size / (wav.sample_size / 8)) / usize

  fb.vline(0, time_str(tm))

  n.times { |col|
    tc += usize;
    if tc >= wav.sample_rate
      tm += 1
      tc %= wav.sample_rate
      fb.vline(col, time_str(tm)) if (tm % 10).zero?
    end
  }
end

#fpos(r) ⇒ Object 



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# File 'lib/wavspa/common.rb', line 13

def fpos(r)
  scale = (@logscale)? log_scaler(r): linear_scaler(r)
  return (scale * @output_width).round
end

#linear_scaler(r) ⇒ Object 



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# File 'lib/wavspa/common.rb', line 9

def linear_scaler(r)
  return 1.0 - ((r - @lo_freq) / @freq_width)
end

#log_scaler(r) ⇒ Object 



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# File 'lib/wavspa/common.rb', line 5

def log_scaler(r)
  return 1.0 - ((Math.log(r / @lo_freq) / @log_base) / @output_width)
end

#time_str(tm) ⇒ Object 



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# File 'lib/wavspa/common.rb', line 52

def time_str(tm)
  m = tm / 60
  s = tm % 60

  if m.zero?
    ret = %q{%d"} % s
  else
    ret = %q{%d'%02d"} % [m, s]
  end

  return ret
end

#up_step(freq) ⇒ Object 



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# File 'lib/wavspa/common.rb', line 18

def up_step(freq)
  return (@logscale)? (freq * @grid_step): (freq + @grid_step)
end