Module: Ms::Calc

Defined in:
lib/ms/calc.rb

Class Method Summary collapse

Class Method Details

.ppm_range_at(mz, ppm) ⇒ Object 



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# File 'lib/ms/calc.rb', line 18

def ppm_range_at(mz, ppm)
  mz = mz.to_f
  tol = ppm_tol_at(mz, ppm)
  mz-tol...mz+tol
end

.ppm_span_at(mz, ppm) ⇒ Object 



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# File 'lib/ms/calc.rb', line 13

def ppm_span_at(mz, ppm)
  tol = ppm_tol_at(mz, ppm)
  [mz-tol, mz+tol]
end

.ppm_tol_at(mz, ppm) ⇒ Object

ppm calculations… maybe use RUnit



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# File 'lib/ms/calc.rb', line 9

def ppm_tol_at(mz, ppm)
  1.0 * mz * ppm / 10**6
end

.round(n, precision) ⇒ Object

Rounds n to the specified precision (ie number of decimal places)



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# File 'lib/ms/calc.rb', line 25

def round(n, precision)
  factor = 10**precision.to_i
  (n * factor).round.to_f / factor
end