Simple arithmetic modifications of sum formulas.
Usage
addMolecules(formula1, formula2, elements = NULL, maxisotopes = 10)
subMolecules(formula1, formula2, elements = NULL, maxisotopes = 10)Arguments
- formula1
Sum formula (can be a vector).
- formula2
Sum formula.
- elements
List of allowed chemical elements, defaults to full periodic system of elements. See
initializeElements.- maxisotopes
Maximum number of isotopes shown in the resulting molecules.
Value
The input vector formula1 will be converted into molecule objects similar
to function getMolecule. However, the results will be amended
or reduced by formula2.
Details
`addMolecules` adds the second argument to the first. `subMolecules` subtracts the second argument from the first. This can be useful to revert e.g. adduct/fragment formation found in ESI mass spectrometry, or to mimic simple chemical reactions. No chemical checks are performed.
Examples
# Remove the proton-adduct from Ethanol
subMolecules("C2H7O", "H")
#> $formula
#> [1] "C2H6O"
#>
#> $score
#> [1] 1
#>
#> $exactmass
#> [1] 46.04186
#>
#> $charge
#> [1] 0
#>
#> $parity
#> [1] "e"
#>
#> $valid
#> [1] "Valid"
#>
#> $DBE
#> [1] 0
#>
#> $isotopes
#> $isotopes[[1]]
#> [,1] [,2] [,3] [,4] [,5] [,6]
#> [1,] 46.0418648 47.04534542 48.04631711 4.904960e+01 5.005324e+01 5.105929e+01
#> [2,] 0.9749152 0.02293559 0.00210353 4.540559e-05 2.816635e-07 2.324709e-10
#> [,7] [,8] [,9] [,10]
#> [1,] 5.206548e+01 5.307171e+01 5.407796e+01 5.508422e+01
#> [2,] 8.458096e-14 1.665930e-17 1.857005e-21 1.107409e-25
#>
#>